Re: [Emc-users] That single channel digital pocket scope has arrived :(
On 04/18/2012 09:14 PM, gene heskett wrote: [huge snip] To make an overly long story a bit shorter, I bought another 2Gb key that was actually formatted fat32, and copied everything I needed to it, then took it over to the neighbors. It installed twice, the second time took. Now I have to figure out how to use it all over again as a lot of the menu's have been changed, as is the key sequences to access them. I can't say as I'm pleased that I actually had to go find a winderz box just to update an open source device. That doesn't tell the whole story though as one of the reasons it kept failing was that the quoted powerup conditions to put it in the DFU mode was wrong, it isn't the|| button to hold down, but a solid punch on the middle, 4way button to close all 4 contacts turned out to be what was required. Thanks Cheers Adrian and list, Gene Pictures! We wanna see pictures! ;-) Mark -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
[Emc-users] 2 issues with LinuxCNC
Hello, gentlemen! I have 2 strange things about LinuxCNC, I hope that someone can help me out with an advice. First is that the machine has only servo thread and servo period set at 50 ns (running at 2 kHz). About a minute after starting LinuxCNC, I get realtime error, check dmesg for details. The strange part is that in dmesg output I see this: [ 1002.729793] In recent history there were [ 1002.729796] 1004274, 805509, 913005, 901971, and 902286 [ 1002.729798] elapsed clocks between calls to the motion controller. [ 1002.729805] This time, there were 968040 which is so anomalously [ 1002.729808] large that it probably signifies a problem with your [ 1002.729810] realtime configuration. For the rest of this run of [ 1002.729813] EMC, this message will be suppressed. The machine consists of: D525MW board 2 gb of ram 4 gb cf card for hdd Mesa 5i23 with 2 7i39s On top of it there is Lucid and fresh install of 2.5.0 version. It has hyperthreading disabled in bios and also isolcpus=1 in grub settings. Increasing servo period to 75 does help avoiding that error message. The 2 things that I do not understand are: 1) why are values 1004274, 805509, 913005, 901971, and 902286 considered as acceptable, but 968040 is not acceptable, given that one of those acceptable values is bigger than this one. 2) I had set servo period to 50 ns, but this is not even close to that. I have latency test running now (not very long, 10 minutes maybe) and max servo period (1 ms) jitter is 11281 ns, max jitter for 25 us base thread is 14312. How do I run glxgears? Pressing alt+f2 and typing glxgears and pressing enter gives error message about error stating file, no such file or directory. The second strange thing is: Previously this machine had 2.5.pre buildbot version (cannot tell, which exactly, but somewhere from winter). Approximately 6-8 weeks ago I had situation, when LinuxCNC stopped showing changes of gpio pin state - not limit/homing switch, not encoder signal inputs, nothing. It was working just fine and then turning machine on after several hours of resoldering encoder wires it just was not showing anything. I thought that it was problem with 5i23 card, so shipped it back to Mesa and received it back this week. Today I put the card in and it still was not responding to any changes in gpio pin state - I measured on the back of the card (where the legs of P3 connector stick out of pcb) with multimeter that limit switches drive that pin from 0,35 V to 5,03 V and back, so the signal was received on the card, but in Show HAL config, in Watch tab not that nor any of the neighboring pins did not change their state. I already thought that the card is still bad. But then I somehow figured to install the 2.5.0 version and it started showing the changes to input pins. It shows the change of joint position, if I turn the servos by hand and I see limit switches working. The motors still do not want to move. Not even steppers. Does anyone have any idea, what might be wrong? Everything was working before that initial stop responding to input pins situation and I have not changed anything in the configs or wiring. Viesturs -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Trajectory planning and other topics from a EMC(LinuxCNC) newbie (TheNewbie)
On 19 March 2012 02:17, Steve Blackmore st...@pilotltd.net wrote: Effectively LinuxCNC only looks ahead one line. This rather depends on what you mean by Look Ahead. One decision that I think might adversely affect LinuxCNC is that as far as I know LinuxCNC will always move in such a way as to be able to stop before the end of the next program line. For programs made of very small linear moves this means that the traverse speed can end up being very much reduced. I think that if this is actually the case it would make more sense to set a lower limit on this distance (INI file setting?) so that the motion system would guarantee stopping in the next program line or (for example) 0.01 Of course, I haven't checked the code, and I might be barking up entirely the wrong tree here. -- atp The idea that there is no such thing as objective truth is, quite simply, wrong. -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] 2 issues with LinuxCNC
On 19 April 2012 13:20, Viesturs Lācis viesturs.la...@gmail.com wrote: First is that the machine has only servo thread and servo period set at 50 ns (running at 2 kHz). About a minute after starting LinuxCNC, I get realtime error, check dmesg for details. I get this with a particular USB webcam inserted. Are there any USB devices attached? But then I somehow figured to install the 2.5.0 version and it started showing the changes to input pins There has been a change to the Hostmot2 watchdog. Perhaps it is related to that? Do you definitely have the Hostmot2 write function attached to a thread .halcmd show thread / halcmd show funct ought to answer that question. One of them show the thread period, and you want to make sure that that keeps changing too. -- atp The idea that there is no such thing as objective truth is, quite simply, wrong. -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] 2 issues with LinuxCNC
19 квітня 2012 р. 15:20 Viesturs Lācis viesturs.la...@gmail.com написав: The motors still do not want to move. Not even steppers. Does anyone have any idea, what might be wrong? Everything was working before that initial stop responding to input pins situation and I have not changed anything in the configs or wiring This much reminds my situation with linear motors not working on 7i39, doesn't it? I just received new SSD for this machine, and probably should install 2.6.0 there, Or 2.4.7. Also, when checking pins with HAL scope, sometimes it does not start showing signals immediately, but only after opening the signal choice dialog again. Might be related too. Andrew -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] That single channel digital pocket scope has arrived :(
Gene, Sorry to hear of the issues you had! I have been away from email today, so only just catching up - but glad to hear you got it sorted out in the end. Regards Adrian On 19 April 2012 11:14, gene heskett ghesk...@wdtv.com wrote: On Wednesday, April 18, 2012 09:05:32 PM gene heskett did opine: On Wednesday, April 18, 2012 04:11:11 PM Adrian Carter did opine: Try using 'benf's firmware, checkout http://www.seeedstudio.com/forum/viewforum.php?f=12 or just search around the interwebz for 'benf firmware'. Much improved. And I believe it includes the 'small signals' capture mode which is one of the things the quad;s community firmware does - makes the buffer the same size as the screen instead of waiting to fill it before display (which is the long delay you speak of). [huge snip] To make an overly long story a bit shorter, I bought another 2Gb key that was actually formatted fat32, and copied everything I needed to it, then took it over to the neighbors. It installed twice, the second time took. Now I have to figure out how to use it all over again as a lot of the menu's have been changed, as is the key sequences to access them. I can't say as I'm pleased that I actually had to go find a winderz box just to update an open source device. That doesn't tell the whole story though as one of the reasons it kept failing was that the quoted powerup conditions to put it in the DFU mode was wrong, it isn't the || button to hold down, but a solid punch on the middle, 4way button to close all 4 contacts turned out to be what was required. Thanks Cheers Adrian and list, Gene -- There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) My web page: http://coyoteden.dyndns-free.com:85/gene If a man slept by day, he had little time to work. That was a satisfying notion to Escargot. -- The Stone Giant, James P. Blaylock -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Trajectory planning and other topics from a EMC(LinuxCNC) newbie (TheNewbie)
I don't think that would work well. Think about the situation where you have several (mostly straight) short line segments, the last being the shortest, and then a 90deg turn. I think many would find it unacceptable to overshoot the last segment 10thou if you were doing something like inside corners. I only have two machines running linuxcnc so far (both commercial gantry routers, both steppers) as a hobby so have limited experience but I don't think the look ahead is that big of an issue *IF* the machine has decent acceleration capability is properly tuned to use it. I can process complex 3d profiling in wood on the big one right about the limit of my spindle hp (~100ipm w/ a 1/2 ballmill). Yes, it probably does limit me slightly when doing a final finishing pass w/ a smaller bit. When Im doing aluminum sheet at ~30ipm its a total non-issue though. I have a factory CNC 3hp Wells Index knee mill w/ DC servos that Im retrofitting (slowly.) If LinuxCNC can keep up on the gantrys it will be no problem FOR ME on the knee mill. But I see how it might be a limiting factor for a modern Hass class speed machine w/ massive spindle hp and feed rates possible when profiling. But those would typ have very high acceleration levels to match. Machines w/ very low acceleration levels will suffer the most as they won't be allowed to get up to speed if you can't slow them down very fast. Its like what they say about driving at night: Dont outdrive your headlights :) More segments of look ahead would no doubt be an improvement. But how much? (seriously, I think we'd all like to know.) Can people give examples of machines and jobs where cutting speed is a problem due to limited look ahead? I don't have enough experience to even be able to guess the magnitude of the issue. Best, Stephen I think that if this is actually the case it would make more sense to set a lower limit on this distance (INI file setting?) so that the motion system would guarantee stopping in the next program line or (for example) 0.01 -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Trajectory planning and other topics from a EMC(LinuxCNC) newbie (TheNewbie)
On 19 April 2012 14:04, Stephen Dubovsky smdubov...@gmail.com wrote: But I see how it might be a limiting factor for a modern Hass class speed machine w/ massive spindle hp and feed rates possible when profiling. It shouldn't be a limit on any machine with decent G-code. I am describing a problem with poor-quality G-code which is made up of thousands of very short line segments. There is a constraint to at least touch every segment (I think) so your concern about the 90 degree bend is covered. -- atp The idea that there is no such thing as objective truth is, quite simply, wrong. -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] 2 issues with LinuxCNC
On Thu, 19 Apr 2012, Viesturs L?cis wrote: Date: Thu, 19 Apr 2012 15:20:09 +0300 From: [UTF-8] Viesturs L?cis viesturs.la...@gmail.com Reply-To: Enhanced Machine Controller (EMC) emc-users@lists.sourceforge.net To: Enhanced Machine Controller (EMC) emc-users@lists.sourceforge.net Subject: [Emc-users] 2 issues with LinuxCNC Hello, gentlemen! I have 2 strange things about LinuxCNC, I hope that someone can help me out with an advice. First is that the machine has only servo thread and servo period set at 50 ns (running at 2 kHz). About a minute after starting LinuxCNC, I get realtime error, check dmesg for details. The strange part is that in dmesg output I see this: [ 1002.729793] In recent history there were [ 1002.729796] 1004274, 805509, 913005, 901971, and 902286 [ 1002.729798] elapsed clocks between calls to the motion controller. [ 1002.729805] This time, there were 968040 which is so anomalously [ 1002.729808] large that it probably signifies a problem with your [ 1002.729810] realtime configuration. For the rest of this run of [ 1002.729813] EMC, this message will be suppressed. The machine consists of: D525MW board 2 gb of ram 4 gb cf card for hdd Mesa 5i23 with 2 7i39s On top of it there is Lucid and fresh install of 2.5.0 version. It has hyperthreading disabled in bios and also isolcpus=1 in grub settings. Increasing servo period to 75 does help avoiding that error message. The 2 things that I do not understand are: 1) why are values 1004274, 805509, 913005, 901971, and 902286 considered as acceptable, but 968040 is not acceptable, given that one of those acceptable values is bigger than this one. 2) I had set servo period to 50 ns, but this is not even close to that. I have latency test running now (not very long, 10 minutes maybe) and max servo period (1 ms) jitter is 11281 ns, max jitter for 25 us base thread is 14312. How do I run glxgears? Pressing alt+f2 and typing glxgears and pressing enter gives error message about error stating file, no such file or directory. The second strange thing is: Previously this machine had 2.5.pre buildbot version (cannot tell, which exactly, but somewhere from winter). Approximately 6-8 weeks ago I had situation, when LinuxCNC stopped showing changes of gpio pin state - not limit/homing switch, not encoder signal inputs, nothing. It was working just fine and then turning machine on after several hours of resoldering encoder wires it just was not showing anything. I thought that it was problem with 5i23 card, so shipped it back to Mesa and received it back this week. Today I put the card in and it still was not responding to any changes in gpio pin state - I measured on the back of the card (where the legs of P3 connector stick out of pcb) with multimeter that limit switches drive that pin from 0,35 V to 5,03 V and back, so the signal was received on the card, but in Show HAL config, in Watch tab not that nor any of the neighboring pins did not change their state. I already thought that the card is still bad. But then I somehow figured to install the 2.5.0 version and it started showing the changes to input pins. It shows the change of joint position, if I turn the servos by hand and I see limit switches working. The motors still do not want to move. Not even steppers. Does anyone have any idea, what might be wrong? Everything was working before that initial stop responding to input pins situation and I have not changed anything in the configs or wiring. Viesturs This does rather sound like a watchdog issue (no outputs working) Note that the 5I23 card returned to you was damaged in the field by excessive input voltage (7V is normally needed to damage the input bus switches which was the situation with your returned card) If you still have a overvoltage situation, this can disable a whole connector of pins at the bus switch for that set of 24 pins. I would check the I/O on the FPGA with nothing else connected ,and check your signal sources carefully for overvoltages Peter Wallace Mesa Electronics -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] 2 issues with LinuxCNC
On Thu, 19 Apr 2012, Andrew wrote: Date: Thu, 19 Apr 2012 15:49:38 +0300 From: Andrew parallel.kinemat...@gmail.com Reply-To: Enhanced Machine Controller (EMC) emc-users@lists.sourceforge.net To: Enhanced Machine Controller (EMC) emc-users@lists.sourceforge.net Subject: Re: [Emc-users] 2 issues with LinuxCNC 19 2012 ??. 15:20 Viesturs L??cis viesturs.la...@gmail.com ??: The motors still do not want to move. Not even steppers. Does anyone have any idea, what might be wrong? Everything was working before that initial stop responding to input pins situation and I have not changed anything in the configs or wiring This much reminds my situation with linear motors not working on 7i39, doesn't it? Have you possibly blown the 7I39 motor power fuse some how? (F1, a little resistor like fuse near the motor power connector) If motor power was applied backwards this might happen and this might also damage encoder inputs. I just received new SSD for this machine, and probably should install 2.6.0 there, Or 2.4.7. Note that does not support the three phase PWM gen Also, when checking pins with HAL scope, sometimes it does not start showing signals immediately, but only after opening the signal choice dialog again. Might be related too. Andrew Peter Wallace Mesa Electronics-- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Trajectory planning and other topics from a EMC(LinuxCNC) newbie (TheNewbie)
2012/4/19 andy pugh bodge...@gmail.com: On 19 April 2012 14:04, Stephen Dubovsky smdubov...@gmail.com wrote: But I see how it might be a limiting factor for a modern Hass class speed machine w/ massive spindle hp and feed rates possible when profiling. It shouldn't be a limit on any machine with decent G-code. I am describing a problem with poor-quality G-code which is made up of thousands of very short line segments. There is a constraint to at least touch every segment (I think) so your concern about the 90 degree bend is covered. I think that this issue is fighting the consequence instead of fixing the real cause. People want to change the look ahead behavior, but I am completely sure that fixing the cause - getting normal g-code is much easier. At least for those things that my machines are doing. My personal opinion is that instead of trying to tweak LinuxCNC for this, users with the g-code consists of very small linear moves problem should join their effort in finding a suitable CAM application. Viesturs -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] That single channel digital pocket scope has arrived :(
On Thursday, April 19, 2012 10:34:37 AM Mark Wendt did opine: On 04/18/2012 09:14 PM, gene heskett wrote: [huge snip] To make an overly long story a bit shorter, I bought another 2Gb key that was actually formatted fat32, and copied everything I needed to it, then took it over to the neighbors. It installed twice, the second time took. Now I have to figure out how to use it all over again as a lot of the menu's have been changed, as is the key sequences to access them. I can't say as I'm pleased that I actually had to go find a winderz box just to update an open source device. That doesn't tell the whole story though as one of the reasons it kept failing was that the quoted powerup conditions to put it in the DFU mode was wrong, it isn't the|| button to hold down, but a solid punch on the middle, 4way button to close all 4 contacts turned out to be what was required. Thanks Cheers Adrian and list, Gene Pictures! We wanna see pictures! ;-) Mark Those will have to wait till I can figure out a way to 'format' the 4Gb micro-sd card I bought to put in it for screen captured image exportation. But I haven't found the docs that say exactly what format it needs to be. ATM, with the card inserted, selecting any function that references that function, locks it up tight with the power switch being the only recovery. And this is with a brand new SanDisk, supposedly pre-formatted fat32(vfat) card. Also, it seems the new software re-arranges to 4 way buttons functions, it now uses the +- top/bottom buttons to cycle thru the menu's and the left- right sides of the 4 way button to modify the value, such as y gain, being adjusted. That will take some getting used to. As for the sd cards formatting, again that seems to be a winderz only function, using a utility called sdformatter, which of course won't run under wine because wine, except for the keyboard/mouse, has no access to USB. Humm, inserted into my reader, its presence is acknowledged, but its not accessible. The usb system issues a boatload of resets but never gets any farther than listing it as sdg, sdh, sdi, sdj. The reader itself indicates it is plugged in by turning on a lights up the whole room blue led Does anyone know what modules are needed to access an SD card while running linux? Cheers, Gene -- There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) My web page: http://coyoteden.dyndns-free.com:85/gene The greatest remedy for anger is delay. -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] 2 issues with LinuxCNC
On 19 April 2012 15:53, Viesturs Lācis viesturs.la...@gmail.com wrote: Yes, it actually was watchdog. I saw in dmesg that it had bit after I increased the servo period from 500 us to 750 us, but completely forgot about the timeout, which also was set at 500 us. That's probably over-cautious. 100mS is likely to be OK. -- atp The idea that there is no such thing as objective truth is, quite simply, wrong. -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Trajectory planning and other topics from a EMC(LinuxCNC) newbie (TheNewbie)
On 19 April 2012 16:13, Stephen Dubovsky smdubov...@gmail.com wrote: For 3d profiling CAM usually writes the g-code. I don't know anyone who would hand calculate tens of thousands of little segments:) As such, I don't know that its necessarily poor quality. It has to generate as many segments as necessary to fit the arbitrary arcs to the specified precision. Well, generating an arc as tiny G1 moves seems a poorer solution than G2 or G3 moves... -- atp The idea that there is no such thing as objective truth is, quite simply, wrong. -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] That single channel digital pocket scope has arrived :(
On Thursday, April 19, 2012 11:19:00 AM Adrian Carter did opine: Gene, Sorry to hear of the issues you had! I have been away from email today, so only just catching up - but glad to hear you got it sorted out in the end. Regards Adrian Ahh, the ghost re-appears! :) Yes, I think I have that problem solved but will need to get used to the function button, the +- and '||' and '||' marked buttons seem to be swapped now. But I bought a SanDisk 4Gb SD card for it last night, and which causes it to freeze up when one of those functions is selected, power switch seems to be the only 'get out' method. I now have that card plugged into my reader/writer, one of those that has a socket for any form factor from CF down to microsd, and its not accessible there either. The card interface turns on its device present led, but that is about it. Any clues on this? Thanks Adrian. Cheers, Gene -- There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) My web page: http://coyoteden.dyndns-free.com:85/gene Refreshed by a brief blackout, I got to my feet and went next door. -- Martin Amis, _Money_ -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] That single channel digital pocket scope has arrived :(
On 04/19/2012 10:15 AM, gene heskett wrote: On Thursday, April 19, 2012 10:34:37 AM Mark Wendt did opine: Humm, inserted into my reader, its presence is acknowledged, but its not accessible. The usb system issues a boatload of resets but never gets any farther than listing it as sdg, sdh, sdi, sdj. The reader itself indicates it is plugged in by turning on a lights up the whole room blue led Does anyone know what modules are needed to access an SD card while running linux? Cheers, Gene On any modern Linux OS, it should Just Work. There's been instances where flash drives had issues in linux, but worked perfectly well in Windows, due to software already installed on the drives. You can always try to reformat it from a terminal, using the command mkfs.vfat, and the location of your device. (/dev/sd?) -- -Mark Ne M'oubliez ---Family Motto Hope for the best, plan for the worst ---Personal Motto -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Trajectory planning and other topics from a EMC(LinuxCNC) newbie (TheNewbie)
Well, generating an arc as tiny G1 moves seems a poorer solution than G2 or G3 moves... There are a number of reasons for doing this: Many CAM packages don't use arcs internally. Breaking arcs into line segments can greatly simplify the maths. When doing 3D work you can quite often get arcs and curves that are not on any standard plane (X-Y, X-Z,Y-Z) They may be cutting curves (i.e not pure arcs) Les -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Trajectory planning and other topics from a EMC(LinuxCNC) newbie (TheNewbie)
2012/4/19 Stephen Dubovsky smdubov...@gmail.com: Around tight curves, that requires lots of short sections w/ high changes in velocity. But you have to go slow within the limits of the machine around those anyway. Just like Andy said - if there is curve in the part, then that is why there are G2 and G3 commands in g-code. Period. Doing arcs with linear moves is _wrong_ approach by definition. Put G2/G3 commands in all arcs and let LinuxCNC do its job - slow down the machine, if necessary, so that it can take given acceleration limits and execute the path with max available velocity. Like I asked: How big of a problem is this really? I guess that this is not the answer to Your question, but still... The task for CNC controller is to control the machine and move it so that it produces the part _exactly_ as described in the code operator feeds in it. The code has to be as simple and unambiguous as possible. If G1 is issued, then it is straight line. If the arc is needed, then use command for arcs instead of using one command in extremely inefficient way to describe another command. Task of CAM application is to produce that code. It should not reinvent the wheel, but use the standard commands from particular language. In case of g-code, G2 and G3 commands belong to the very very basics of this language. IMHO any CAM application, that does not use full potential of G2/G3 moves, is a crap, regardless of other features in it, because: 1) the code consist of such a small moves, that operator cannot understand it and cannot adjust it by hand, if needed; 2) the code is so long that moving around the file is just a disaster; 3) files for complex parts can exceed tenths of thousands of lines, which makes up the file size and also creates unnecessary load for the CNC controller, especially when it is loaded; 4) if such a basic commands have not been implemented, I think that there is serious reason to doubt the overall implementation of any other features, besides G1 moves... I think that in the end it is all about efficiency - smaller g-code file is easier for operator to overlook, easier for CNC controller to handle and efficient g-code leads to efficient work, as the job gets done faster. It seems like CAM authors are living on different planet, if they think that CNC controller should be equally efficient also with poor code. I think that this the same principle as give me Porsche 911 and ask to do a lap time as fast as Michael Schumacher. And then ask me, why was I so much slower, if I had the same car and in the same race track? Viesturs -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] That single channel digital pocket scope has arrived :(
On Thursday, April 19, 2012 12:08:58 PM Mark Cason did opine: On 04/19/2012 10:15 AM, gene heskett wrote: On Thursday, April 19, 2012 10:34:37 AM Mark Wendt did opine: Humm, inserted into my reader, its presence is acknowledged, but its not accessible. The usb system issues a boatload of resets but never gets any farther than listing it as sdg, sdh, sdi, sdj. The reader itself indicates it is plugged in by turning on a lights up the whole room blue led Does anyone know what modules are needed to access an SD card while running linux? Cheers, Gene On any modern Linux OS, it should Just Work. There's been instances where flash drives had issues in linux, but worked perfectly well in Windows, due to software already installed on the drives. You can always try to reformat it from a terminal, using the command mkfs.vfat, and the location of your device. (/dev/sd?) Ahh, but which sd* is it: From dmesg when I plug in the reader: usb 1-2.4: new high-speed USB device number 52 using ehci_hcd hub 1-2:1.0: port 4 not reset yet, waiting 10ms usb 1-2.4: default language 0x0409 usb 1-2.4: udev 52, busnum 1, minor = 51 usb 1-2.4: New USB device found, idVendor=05e3, idProduct=070e usb 1-2.4: New USB device strings: Mfr=0, Product=1, SerialNumber=2 usb 1-2.4: Product: USB Storage usb 1-2.4: SerialNumber: 9317 usb 1-2.4: usb_probe_device usb 1-2.4: configuration #1 chosen from 1 choice usb 1-2.4: adding 1-2.4:1.0 (config #1, interface 0) usbserial_generic 1-2.4:1.0: usb_probe_interface usbserial_generic 1-2.4:1.0: usb_probe_interface - got id usb-storage 1-2.4:1.0: usb_probe_interface usb-storage 1-2.4:1.0: usb_probe_interface - got id scsi44 : usb-storage 1-2.4:1.0 drivers/usb/core/inode.c: creating file '052' scsi 44:0:0:0: Direct-Access Generic STORAGE DEVICE 9317 PQ: 0 ANSI: 0 sd 44:0:0:0: Attached scsi generic sg4 type 0 scsi 44:0:0:1: Direct-Access Generic STORAGE DEVICE 9317 PQ: 0 ANSI: 0 sd 44:0:0:1: Attached scsi generic sg7 type 0 scsi 44:0:0:2: Direct-Access Generic STORAGE DEVICE 9317 PQ: 0 ANSI: 0 sd 44:0:0:2: Attached scsi generic sg8 type 0 sd 44:0:0:0: [sdg] Attached SCSI removable disk scsi 44:0:0:3: Direct-Access Generic STORAGE DEVICE 9317 PQ: 0 ANSI: 0 sd 44:0:0:3: Attached scsi generic sg9 type 0 sd 44:0:0:1: [sdh] Attached SCSI removable disk sd 44:0:0:2: [sdi] Attached SCSI removable disk sd 44:0:0:3: [sdj] Attached SCSI removable disk Then I plug this microSDHC card into the reader, its led comes on, but no further data appears in the next dmesg until many seconds later when it adds this: hub 1-2:1.0: state 7 ports 4 chg evt 0010 usb 1-2.4: reset high-speed USB device number 52 using ehci_hcd hub 1-2:1.0: port 4 not reset yet, waiting 10ms hub 1-2:1.0: port 4 not reset yet, waiting 10ms usb 1-2.4: reset high-speed USB device number 52 using ehci_hcd hub 1-2:1.0: port 4 not reset yet, waiting 10ms hub 1-2:1.0: state 7 ports 4 chg evt 0010 hub 1-2:1.0: port 4 not reset yet, waiting 10ms usb 1-2.4: reset high-speed USB device number 52 using ehci_hcd hub 1-2:1.0: port 4 not reset yet, waiting 10ms hub 1-2:1.0: port 4 not reset yet, waiting 10ms usb 1-2.4: reset high-speed USB device number 52 using ehci_hcd hub 1-2:1.0: port 4 not reset yet, waiting 10ms hub 1-2:1.0: port 4 not reset yet, waiting 10ms usb 1-2.4: reset high-speed USB device number 52 using ehci_hcd hub 1-2:1.0: port 4 not reset yet, waiting 10ms sd 44:0:0:3: Device offlined - not ready after error recovery hub 1-2:1.0: port 4 not reset yet, waiting 10ms usb 1-2.4: reset high-speed USB device number 52 using ehci_hcd hub 1-2:1.0: state 7 ports 4 chg evt 0010 hub 1-2:1.0: port 4 not reset yet, waiting 10ms hub 1-2:1.0: port 4 not reset yet, waiting 10ms usb 1-2.4: reset high-speed USB device number 52 using ehci_hcd hub 1-2:1.0: port 4 not reset yet, waiting 10ms hub 1-2:1.0: port 4 not reset yet, waiting 10ms hub 1-2:1.0: state 7 ports 4 chg evt 0010 usb 1-2.4: reset high-speed USB device number 52 using ehci_hcd hub 1-2:1.0: port 4 not reset yet, waiting 10ms hub 1-2:1.0: port 4 not reset yet, waiting 10ms usb 1-2.4: reset high-speed USB device number 52 using ehci_hcd hub 1-2:1.0: port 4 not reset yet, waiting 10ms hub 1-2:1.0: port 4 not reset yet, waiting 10ms usb 1-2.4: reset high-speed USB device number 52 using ehci_hcd hub 1-2:1.0: port 4 not reset yet, waiting 10ms hub 1-2:1.0: state 7 ports 4 chg evt 0010 hub 1-2:1.0: port 4 not reset yet, waiting 10ms usb 1-2.4: reset high-speed USB device number 52 using ehci_hcd hub 1-2:1.0: port 4 not reset yet, waiting 10ms sd 44:0:0:1: Device offlined - not ready after error recovery hub 1-2:1.0: port 4 not reset yet, waiting 10ms usb 1-2.4: reset high-speed USB device number 52 using ehci_hcd hub 1-2:1.0: port 4 not reset yet, waiting 10ms hub 1-2:1.0: port 4 not reset yet, waiting 10ms usb 1-2.4: reset high-speed USB device number 52 using ehci_hcd hub 1-2:1.0: port 4 not reset
Re: [Emc-users] Trajectory planning and other topics from a EMC(LinuxCNC) newbie (TheNewbie)
I think this is a fairly common problem. There are a number Gcode generators out there that take curvy cutting patterns and turn them into huge files full of short G1 moves. The Gcode generator people expect the machine controller to gobble up the crappy G code and create smooth motions at high speeds. The one commercial application I ran into was for a vinyl cutter for sign making applications. They wanted to run at 1000 ipm while processing Gcode with segment lengths of a couple of thousands of an inch. It was crazy. Needless to say, a solution was never found. And their machines are still running slowly (the last I heard) due to the poor quality Gcode. Dave On 4/19/2012 11:13 AM, Stephen Dubovsky wrote: Im aware the 90deg case is currently covered. I was commenting to the OP who thought about allowing the trajectory planner to run a little faster than it can see could end badly even with such a common case. For 3d profiling CAM usually writes the g-code. I don't know anyone who would hand calculate tens of thousands of little segments:) As such, I don't know that its necessarily poor quality. It has to generate as many segments as necessary to fit the arbitrary arcs to the specified precision. Around tight curves, that requires lots of short sections w/ high changes in velocity. But you have to go slow within the limits of the machine around those anyway. On the longer smooth arcs, it generates longer segments (Im using Visual mill pkg in Alibre) so no problem there either. Are there common CAM pkgs that dont do this well? I guess if I set the curve fit in CAM to a very small number (currently using 0.001) it would bog my machine down. Like I asked: How big of a problem is this really? I can imagine a Hass class machine that can hold tenths at high speed could be fed a huge file w/ tenths arc fitting. Even allowing some small additional error like G64 P0.0001 I can envision a scenario which might not run at the programmed feed rate. So I ask again: Are there real world examples of it being a problem? Stephen On Thu, Apr 19, 2012 at 9:33 AM, andy pughbodge...@gmail.com wrote: On 19 April 2012 14:04, Stephen Dubovskysmdubov...@gmail.com wrote: But I see how it might be a limiting factor for a modern Hass class speed machine w/ massive spindle hp and feed rates possible when profiling. It shouldn't be a limit on any machine with decent G-code. I am describing a problem with poor-quality G-code which is made up of thousands of very short line segments. There is a constraint to at least touch every segment (I think) so your concern about the 90 degree bend is covered. -- atp The idea that there is no such thing as objective truth is, quite simply, wrong. -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Trajectory planning and other topics from a EMC(LinuxCNC) newbie (TheNewbie)
-Original Message- From: Viesturs Lacis [mailto:viesturs.la...@gmail.com] Sent: Thursday, April 19, 2012 11:08 AM To: Enhanced Machine Controller (EMC) Subject: Re: [Emc-users] Trajectory planning and other topics from a EMC(LinuxCNC) newbie (TheNewbie) snip Just like Andy said - if there is curve in the part, then that is why there are G2 and G3 commands in g-code. Period. Doing arcs with linear moves is _wrong_ approach by definition. Put G2/G3 commands in all arcs and let LinuxCNC do its job - slow down the machine, if necessary, so that it can take given acceleration limits and execute the path with max available velocity. There are many cases where short segments are currently the only workable solution. Among these: 1) The arc is not parallel to the XY, XZ, or YZ planes 2) The path is curved, but not a true arc. It could be an oval, an ellipse, or even a spline or nurbs path. 3) The path is from a digitized source using a sample object or a photograph. With increasing usage of 3D modeling these sorts of paths are becoming more common. Steve Stallings -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Trajectory planning and other topics from a EMC(LinuxCNC) newbie (TheNewbie)
The big problem is that very often the curves in the drawing are not true arcs. This is especially common in artistic and sign work. The quality of the CAM output is directly dependent on the quality of the input drawing. Drawings that contains just arcs and lines will generate nice clean code. Drawings with lots of splines and other curves will always generate big code. Some CAM packages try to do arc fitting on curves but technically this is just as bad as breaking them up into lines. You are compromising the accuracy of the final code. When it comes to 3D work, all bets are off because very often the final tool path will not follow true arcs. Les On 19/04/2012 17:31, Dave wrote: I think this is a fairly common problem. There are a number Gcode generators out there that take curvy cutting patterns and turn them into huge files full of short G1 moves. The Gcode generator people expect the machine controller to gobble up the crappy G code and create smooth motions at high speeds. The one commercial application I ran into was for a vinyl cutter for sign making applications. They wanted to run at 1000 ipm while processing Gcode with segment lengths of a couple of thousands of an inch. It was crazy. Needless to say, a solution was never found. And their machines are still running slowly (the last I heard) due to the poor quality Gcode. Dave -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Trajectory planning and other topics from a EMC(LinuxCNC) newbie (TheNewbie)
On 19 April 2012 18:44, Steve Stallings steve...@newsguy.com wrote: There are many cases where short segments are currently the only workable solution. Among these: ... 2) The path is curved, but not a true arc. It could be an oval, an ellipse, or even a spline or nurbs path. I _think_ there is a 3D NURBS poised to appear in LinuxCNC. However that will be a LinucCNC-unique option, so I don't expect any CAM systems to support it. -- atp The idea that there is no such thing as objective truth is, quite simply, wrong. -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Trajectory planning and other topics from a EMC(LinuxCNC) newbie (TheNewbie)
2012/4/19 Les Newell les.new...@fastmail.co.uk: The big problem is that very often the curves in the drawing are not true arcs. This is especially common in artistic and sign work. The quality of the CAM output is directly dependent on the quality of the input drawing. Drawings that contains just arcs and lines will generate nice clean code. Drawings with lots of splines and other curves will always generate big code. Some CAM packages try to do arc fitting on curves but technically this is just as bad as breaking them up into lines. You are compromising the accuracy of the final code. Ok, I agree to these arguments. Les, Your company is providing a CAM application. Have You considered implementing Nurbs for all the splines and other nasty geometry, that cannot be described by arcs? LinuxCNC has support for Nurbs (but I guess that Mach users might be Your biggest audience and I guess that Mach is not even close to accepting Nurbs code). Viesturs -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Trajectory planning and other topics from a EMC(LinuxCNC) newbie (TheNewbie)
Viesturs Lācis wrote: I think that this issue is fighting the consequence instead of fixing the real cause. People want to change the look ahead behavior, but I am completely sure that fixing the cause - getting normal g-code is much easier. At least for those things that my machines are doing. There are two issues. One is certainly G-code that asks for what the machine cannot deliver. High speeds into 90 degree turn. The other, however, is more subtle. Assume a surface profiling task where the machine flies along in an almost straight line but moving, say, the Z axis up and down a bit. There are many short segments, but the G-code is well-behaved, never asking for great acceleration anywhere, but the vectors (or arcs) are very short. And, it gradually slows down at the end of the line, so no excessive deceleration is asked for. Well, LinuxCNC forces this program to run slowly, because it demands that the velocity never exceeds what the machine can decelerate to a stop in the next block. My personal opinion is that instead of trying to tweak LinuxCNC for this, users with the g-code consists of very small linear moves problem should join their effort in finding a suitable CAM application. In the case above, there may NOT be a CAM solution for this problem, if you are forced to specify all moves in basic G-code, and only check velocities and accelerations for this block and the next one block. NURBS might solve the problem, at least by vastly reducing the number of blocks to be scanned. One quick and dirty fix (I tend to do things this way and regret it later) is to have an option that turns off the velocity limiting. If the G-code is well-behaved and gives decreasing velocities as it approaches a corner, this should allow the program to run faster. But, if the G-code ever fails to handle this well, it will cause a following error stop in the middle of a program! Not a good thing. Jon -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] That single channel digital pocket scope has arrived :(
On 04/19/2012 11:25 AM, gene heskett wrote: On Thursday, April 19, 2012 12:08:58 PM Mark Cason did opine: On 04/19/2012 10:15 AM, gene heskett wrote: On Thursday, April 19, 2012 10:34:37 AM Mark Wendt did opine: Humm, inserted into my reader, its presence is acknowledged, but its not accessible. The usb system issues a boatload of resets but never gets any farther than listing it as sdg, sdh, sdi, sdj. The reader itself indicates it is plugged in by turning on a lights up the whole room blue led Does anyone know what modules are needed to access an SD card while running linux? Cheers, Gene On any modern Linux OS, it should Just Work. There's been instances where flash drives had issues in linux, but worked perfectly well in Windows, due to software already installed on the drives. You can always try to reformat it from a terminal, using the command mkfs.vfat, and the location of your device. (/dev/sd?) Snip Plugging the whole thing into a direct usb port fiddles around trying to find something for a couple of minutes, but winds up looking like this in dmesg: ehci_hcd :00:02.1: port 5 full speed -- companion ehci_hcd :00:02.1: GetStatus port:5 status 003001 0 ACK POWER OWNER sig=se0 CONNECT hub 1-0:1.0: port 5 not reset yet, waiting 50ms hub 1-0:1.0: state 7 ports 10 chg evt 0020 ehci_hcd :00:02.1: GetStatus port:5 status 001002 0 ACK POWER sig=se0 CSC hub 1-0:1.0: logical disconnect on port 5 hub 1-0:1.0: state 7 ports 10 chg 0020 evt 0020 hub 1-0:1.0: port 5, status 0100, change , 12 Mb/s usb 1-5: USB disconnect, device number 53 usb 1-5: unregistering device usb 1-5: unregistering interface 1-5:1.0 usb 1-5: usb_disable_device nuking all URBs Thanks Cheers Mark, Gene My first rule of thumb, if it doesn't work with a hub, then try it directly. It looks like the USB port is not reading the drive correctly. Since this is a microSDHC, have you tried using another adapter to put it in? I've run into a similar problem when I used a different manufacturers adapter on one of my Sandisk cards. (I'm using a laptop, so the card reader is already built into my computer.) Also, have you tried running lsusb -vv? -- -Mark Ne M'oubliez ---Family Motto Hope for the best, plan for the worst ---Personal Motto -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Trajectory planning and other topics from a EMC(LinuxCNC) newbie (TheNewbie)
I agree that there are always cases where curve fitting simply doesn't work. But I have seen some large curvy lines in a single plane that could have been curve fitted, that spanned over several feet of distance that were described as G1 segments that were no more than .005 inches long. That is simply bad Gcode. Dave On 4/19/2012 12:45 PM, Les Newell wrote: The big problem is that very often the curves in the drawing are not true arcs. This is especially common in artistic and sign work. The quality of the CAM output is directly dependent on the quality of the input drawing. Drawings that contains just arcs and lines will generate nice clean code. Drawings with lots of splines and other curves will always generate big code. Some CAM packages try to do arc fitting on curves but technically this is just as bad as breaking them up into lines. You are compromising the accuracy of the final code. When it comes to 3D work, all bets are off because very often the final tool path will not follow true arcs. Les On 19/04/2012 17:31, Dave wrote: I think this is a fairly common problem. There are a number Gcode generators out there that take curvy cutting patterns and turn them into huge files full of short G1 moves. The Gcode generator people expect the machine controller to gobble up the crappy G code and create smooth motions at high speeds. The one commercial application I ran into was for a vinyl cutter for sign making applications. They wanted to run at 1000 ipm while processing Gcode with segment lengths of a couple of thousands of an inch. It was crazy. Needless to say, a solution was never found. And their machines are still running slowly (the last I heard) due to the poor quality Gcode. Dave -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Nonplanar arcs
What about a new plane selection block which allowed you to define an arbitrary plane using 3 points? On Apr 19, 2012, at 2:32 PM, Chris Radek wrote: On Thu, Apr 19, 2012 at 09:18:52PM +0300, Viesturs L??cis wrote: How hard would it be to add that? It would require 3 coordinates for each of start, end and center point. The guts of linuxcnc already support this kind of motion and have for some time. The problem is representing them in gcode. I do not agree that 3 coordinates is enough to identify a 3d arc uniquely. Consider the points start:-1,0,0 center:0,0,0 end:1,0,0. You can draw many arcs with that specification. Also it is not true that you can't get nonplanar arcs in linuxcnc. If you rotate around the Z axis (G10 R) and do a G18 or G19 arc, you'll see that it's not in any plane. Of course you can only specify some arcs this way (but enough to let any gcode program keep working when rotated.) Chris -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Nonplanar arcs
2012/4/19 Chris Radek ch...@timeguy.com: On Thu, Apr 19, 2012 at 09:18:52PM +0300, Viesturs L??cis wrote: How hard would it be to add that? It would require 3 coordinates for each of start, end and center point. The guts of linuxcnc already support this kind of motion and have for some time. The problem is representing them in gcode. I do not agree that 3 coordinates is enough to identify a 3d arc uniquely. Consider the points start:-1,0,0 center:0,0,0 end:1,0,0. You can draw many arcs with that specification. Uhhh, You are right, halfcircles. All three points are on a straight line, around which the arc can freely rotate. I guess that this is special case (is there any other?), in which such an arc should be splitted in 2 quartercircles. But how to tell CAM package to do so? I have experience with a CAM package, which had such an option to split arcs, that are 180 degrees or longer, but that is CAM application specifically for waterjets and plasmas (do not know about lasers). Viesturs -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Trajectory planning and other topics from a EMC(LinuxCNC) newbie (TheNewbie)
On 4/19/2012 1:53 PM, Jon Elson wrote: Viesturs Lācis wrote: 2012/4/19 Stephen Dubovskysmdubov...@gmail.com: Around tight curves, that requires lots of short sections w/ high changes in velocity. But you have to go slow within the limits of the machine around those anyway. Just like Andy said - if there is curve in the part, then that is why there are G2 and G3 commands in g-code. Period. Doing arcs with linear moves is _wrong_ approach by definition. But, LinuxCNC does not do arbitrary arcs, but only arcs in one of the three orthogonal planes. Also, if your arc is not a segment of a circle but some other curve, it has to be broken into multiple arcs anyway to approximate the desired curve. Jon I think the real issue is that the CAM programs are breaking the target shape into a sequence of short arcs so as to stay within some error band. Instead, the program could break the target shape into a sequence of arcs with common exit and entry tangents. The program could maintain the same error limits. By doing that, linuxcnc would never have to come to a full stop. The approximation as a sequence of arcs would generally (always?) have fewer (or the same number of) lines of gcode than the approximation as a sequence of line segments. Others have stated that arcs must be in one of three orthogonal planes. Since linuxcnc can do helices, that isn't precisely true. Is anyone here interested in writing a filter that takes as input a tolerance (error band) and a sequence of motions (arcs and line segments) and generates a new sequence of motions that duplicates the original within the error band? It sounds like that would be one way to address the problem. Regards, Ken Ken -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Nonplanar arcs
:) not so fast - never is a very long time! :) On Apr 19, 2012 2:00 PM, Chris Radek ch...@timeguy.com wrote: On Thu, Apr 19, 2012 at 09:45:42PM +0300, Viesturs L??cis wrote: Uhhh, You are right, halfcircles. All three points are on a straight line, around which the arc can freely rotate. I guess that this is special case (is there any other?), That is just the worst problem. Your system doesn't uniquely identify any arc. For every start, center, end points there are a pair of arcs that share the points. This is why we have G2/G3. If you don't have a normal vector you can't say which way is clockwise, so G2/G3 don't make sense. This is also a problem you get when you specify the arbitrary plane with three points, as was proposed by Ian M. The correct solution is probably to specify the plane's normal vector. While it's entirely possible to do, I doubt anyone would ever use this feature if someone did the work to implement it. Chris -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Trajectory planning and other topics from a EMC(LinuxCNC) newbie (TheNewbie)
SheetCam does not support NURBS curves internally. When it imports a drawing, all non-circular curves are broken down into lots of very small line segments. It then does arc matching on those line segments and any other line segments in the drawing before finally merging any ludicrously short line segments. You can specify the tolerance for arc matching and line merging. I have no intention of adding NURBS functionality. Only a few controls support it and the maths involved in generating robust NURBS offsets is far beyond my capabilities. Les Ok, I agree to these arguments. Les, Your company is providing a CAM application. Have You considered implementing Nurbs for all the splines and other nasty geometry, that cannot be described by arcs? LinuxCNC has support for Nurbs (but I guess that Mach users might be Your biggest audience and I guess that Mach is not even close to accepting Nurbs code). -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Nonplanar arcs
On 19 April 2012 19:57, Chris Radek ch...@timeguy.com wrote: That is just the worst problem. Your system doesn't uniquely identify any arc. For every start, center, end points there are a pair of arcs that share the points. This is why we have G2/G3. If you don't have a normal vector you can't say which way is clockwise, so G2/G3 don't make sense. I _think_ you could disallow collinear points, and always choose the shorter of the two arcs. If you want the longer one, then you have to split it. I think G6 is vacant? -- atp The idea that there is no such thing as objective truth is, quite simply, wrong. -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Trajectory planning and other topics from a EMC(LinuxCNC) newbie (TheNewbie)
On 4/19/2012 9:02 PM, Kenneth Lerman wrote: Is anyone here interested in writing a filter that takes as input a tolerance (error band) and a sequence of motions (arcs and line segments) and generates a new sequence of motions that duplicates the original within the error band? It sounds like that would be one way to address the problem. Slic3r has implemented a similar feature, the algorithms can be snitched there. I have also made some calculations here, but for actual refinements of arcs segments: bernhardkubicek.soup.io/post/191097625/If-you-have-a-path-of-segments -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Trajectory planning and other topics from a EMC(LinuxCNC) newbie (TheNewbie)
2012/4/19 Les Newell les.new...@fastmail.co.uk: SheetCam does not support NURBS curves internally. When it imports a drawing, all non-circular curves are broken down into lots of very small line segments. It then does arc matching on those line segments and any other line segments in the drawing before finally merging any ludicrously short line segments. You can specify the tolerance for arc matching and line merging. I have no intention of adding NURBS functionality. Only a few controls support it and the maths involved in generating robust NURBS offsets is far beyond my capabilities. Ok, got it, thanks for explanation! Viesturs -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Nonplanar arcs
2012/4/19 andy pugh bodge...@gmail.com: On 19 April 2012 19:57, Chris Radek ch...@timeguy.com wrote: That is just the worst problem. Your system doesn't uniquely identify any arc. For every start, center, end points there are a pair of arcs that share the points. This is why we have G2/G3. If you don't have a normal vector you can't say which way is clockwise, so G2/G3 don't make sense. I _think_ you could disallow collinear points, and always choose the shorter of the two arcs. If you want the longer one, then you have to split it. Seems reasonable. But since hand-writing is suitable for simple parts, but nonplanar arcs are most wanted in 3D parts, I have no idea, how to get a CAM app to do so? I think G6 is vacant? AFAIK Araisrobo branch has G6 for real nurbs, but that could be moved to the existing nurbs command G5 to replace existing implementation. Viesturs -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Trajectory planning and other topics from a EMC(LinuxCNC) newbie (TheNewbie)
No, I was actually working with an OEM who sold a sign software package that generated Gcode (very expensive). The problem was that their software generated way too many short segments for no good reason which caused problems on the machine controls (it wasn't LinuxCNC or Mach3). They simply refused to alter their code saying that the machine control should be able to handle as many short segments as they want to throw at it and still run at high speeds. The machine control choked badly (no surprise) and was running 10 or 15% of the desired speed. In the end, I don't think that anything was ever fixed. And the machines still run slowly. I later learned that this is a common stance in the art industry. They expect the machine controller to handle whatever garbage they throw at it. Artists and some of the people associated with artists tend to live in different realm, reality, or dimension. ;-) Logic is oftentimes discarded! Dave On 4/19/2012 3:53 PM, Les Newell wrote: Dave, Is it possible the CAM package had been set up for ridiculously close tolerances? Maybe it was simply a case of changing a parameter somewhere to increase the tolerance. Les On 19/04/2012 19:01, Dave wrote: I agree that there are always cases where curve fitting simply doesn't work. But I have seen some large curvy lines in a single plane that could have been curve fitted, that spanned over several feet of distance that were described as G1 segments that were no more than .005 inches long. That is simply bad Gcode. Dave -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] That single channel digital pocket scope has arrived :(
On 20 April 2012 01:38, gene heskett ghesk...@wdtv.com wrote: On Thursday, April 19, 2012 11:19:00 AM Adrian Carter did opine: Gene, Sorry to hear of the issues you had! I have been away from email today, so only just catching up - but glad to hear you got it sorted out in the end. Regards Adrian Ahh, the ghost re-appears! :) Yes, I think I have that problem solved but will need to get used to the function button, the +- and '||' and '||' marked buttons seem to be swapped now. But I bought a SanDisk 4Gb SD card for it last night, and which causes it to freeze up when one of those functions is selected, power switch seems to be the only 'get out' method. I now have that card plugged into my reader/writer, one of those that has a socket for any form factor from CF down to microsd, and its not accessible there either. The card interface turns on its device present led, but that is about it. Any clues on this? Wow you never get it easy do you :) Well I'm assuming you've checked the usual issues and that you are sure its not just a bad SD card despite it being new (I've had a few :( that or my DSLR camera enjoys eating them) and outside that I'd be guessing right now. Will have a poke around the Seeed forums and see if anything jumps out at me. Adrian Thanks Adrian. Cheers, Gene -- There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) My web page: http://coyoteden.dyndns-free.com:85/gene Refreshed by a brief blackout, I got to my feet and went next door. -- Martin Amis, _Money_ -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
[Emc-users] Hardinge HCNC Retrofit/Rebuild
Hello, If anyone is interested I posted some picture of my HCNC project machine. I have started the retro rebuild process. Warning: the pictures my be disturbing to some machine lovers because of all the missing parts...:) http://www.conesusmachinetool.com/1/post/2012/04/hardinge-hcnc-lathe-rebuildretrofit.html Because of the parts I am missing I am going to try to use a DC motor (as suggest by someone on the IRC) or a stepper motor in place of the missing air motor on the tool changer. I am going to start there. I have the axis motors but not sure if I will use them yet. I can just as easily replace them. I am leaning toward Gecko servo drives so if I go that way I will probably replace them because of the voltage limit on those drives. I need a spindle motor. I have a PacSci AC servo motor (1.35KW) and drive. I have not run the numbers to see if it would be a good choice. My gut feeling is that it might be on the small side. If it is I will probably go to a 3phase 3HP with VFD? Not sure what HP it came with. Will build a custom enclosure similar to the mill enclosures I make. I also have the coolant tank and pump and one of the pictures shows a hydraulic panel? I have the over spindle mounted cut off slide? Was that hydraulic? It looks like the collet closer was pneumatic? I will update the blog as I make progress. I appreciate the feedback and help I have gotten so far and hopefully something from this project will benefit others in the future. Oh and of course it will be controlled by LinuxCNC... Mike -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Trajectory planning and other topics from a EMC(LinuxCNC) newbie (TheNewbie)
Viesturs Lācis wrote: 2012/4/19 Jon Elson el...@pico-systems.com: But, LinuxCNC does not do arbitrary arcs, but only arcs in one of the three orthogonal planes. How hard would it be to add that? It would require 3 coordinates for each of start, end and center point. The first problem is that classic RS-274D does not permit it. Several CNC vendors have provided their own proprietary extensions to code this. Jon -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Nonplanar arcs
Chris Radek wrote: The correct solution is probably to specify the plane's normal vector. While it's entirely possible to do, I doubt anyone would ever use this feature if someone did the work to implement it. Yup, messy. Maybe NURBS is really the way to go, it seems to solve several of these problems all at once (I think!) Jon -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Trajectory planning and other topics from a EMC(LinuxCNC) newbie (TheNewbie)
Kenneth Lerman wrote: Others have stated that arcs must be in one of three orthogonal planes. Since linuxcnc can do helices, that isn't precisely true. A helix is a special case, where an arc in one of the 3 defined planes adds a coordinated linear movement of one axis not involved in the arc move. That is a pretty specific case. It DOES allow some other types of moves, though. Jon -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Hardinge HCNC Retrofit/Rebuild
Hi Mike, Looks like a fun project. But,, I dont want to discourage you too much but if you use a Stepper or something to turn the turret you will have to address some issues. The turret has to have air to hold it down while machining. this air is part of a pretty complicated system involving the turret motor,the turret stop it also lifts the turret .also the whole thing has a small amount of regulated pressure to keep the oil and chips out of the carrage. Do you have a set of prints? Not saying it cant be done Im just saying by the time you address all these things it might be easier to replace the air motor. Terry - Original Message - From: Mike Cinquino mcinqu...@gmail.com To: emc-users@lists.sourceforge.net Cc: Sent: Thursday, April 19, 2012 8:23 PM Subject: [Emc-users] Hardinge HCNC Retrofit/Rebuild Hello, If anyone is interested I posted some picture of my HCNC project machine. I have started the retro rebuild process. Warning: the pictures my be disturbing to some machine lovers because of all the missing parts...:) http://www.conesusmachinetool.com/1/post/2012/04/hardinge-hcnc-lathe-rebuildretrofit.html Because of the parts I am missing I am going to try to use a DC motor (as suggest by someone on the IRC) or a stepper motor in place of the missing air motor on the tool changer. I am going to start there. I have the axis motors but not sure if I will use them yet. I can just as easily replace them. I am leaning toward Gecko servo drives so if I go that way I will probably replace them because of the voltage limit on those drives. I need a spindle motor. I have a PacSci AC servo motor (1.35KW) and drive. I have not run the numbers to see if it would be a good choice. My gut feeling is that it might be on the small side. If it is I will probably go to a 3phase 3HP with VFD? Not sure what HP it came with. Will build a custom enclosure similar to the mill enclosures I make. I also have the coolant tank and pump and one of the pictures shows a hydraulic panel? I have the over spindle mounted cut off slide? Was that hydraulic? It looks like the collet closer was pneumatic? I will update the blog as I make progress. I appreciate the feedback and help I have gotten so far and hopefully something from this project will benefit others in the future. Oh and of course it will be controlled by LinuxCNC... Mike -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Nonplanar arcs
..suppose you had a five axis millimg setup with the normal xyz plus alpha-beta rotation of the cutter rotation axis about a shperical center. then suppose that to take advantage of these spindle axes, you wanted to mill a planar facet on a part that was tipped at say five degrees to the x and five degrees to the y. the facet contains pockets with circular features that run normal to the tipped face, or circular bosses with tap bores running along their axis. it would be nice to rotate the entire coordinate system to align with some of the features of interest on a part that is otherwise already set up and positioned in the machine. another solution would be to accurately rotate the part about a and b and c axes, and just keep track of what that does to the xyz zero on the part, and then all the 2d gcode still applies. this is probably the more common of the five axis styles. maybe g16 a b c is an arbitrary interpolation plane for arcs, where abc are rotations relative to the abc origin (= the usual xyz directions)? xyzijk would have the usual meanings. maybe g15 p q r is an arbitrary x'y'z' coordinate system, where pqr is a unit vector relative to the usual xyz unit vector? xyzijk would be in the sense of the rotated x'y'z' coordinate system, and g16 would act on top of this new coordinate system. maybe g14 selects no preferred plane, and disallows g2/3 until g16-19 are set. maybe it also sets x'y'z' = xyz coordinates? --- On Thu, 4/19/12, Chris Radek ch...@timeguy.com wrote: From: Chris Radek ch...@timeguy.com Subject: Re: [Emc-users] Nonplanar arcs To: Enhanced Machine Controller (EMC) emc-users@lists.sourceforge.net Date: Thursday, April 19, 2012, 11:57 AM On Thu, Apr 19, 2012 at 09:45:42PM +0300, Viesturs L??cis wrote: Uhhh, You are right, halfcircles. All three points are on a straight line, around which the arc can freely rotate. I guess that this is special case (is there any other?), That is just the worst problem. Your system doesn't uniquely identify any arc. For every start, center, end points there are a pair of arcs that share the points. This is why we have G2/G3. If you don't have a normal vector you can't say which way is clockwise, so G2/G3 don't make sense. This is also a problem you get when you specify the arbitrary plane with three points, as was proposed by Ian M. The correct solution is probably to specify the plane's normal vector. While it's entirely possible to do, I doubt anyone would ever use this feature if someone did the work to implement it. Chris -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Hardinge HCNC Retrofit/Rebuild
The cuttoff slide was air over hydrolic to make it move smoother, just get rid of it and use a cut off for a lathe that way you can put a little chamfer on the OD before you part off. Collet closer is air.Hope you have the solenoids for it because they keep the collet closed after the air is released.There is alot of o-rings inside the closer so if the machine has been sitting for a while start putting a few drops of air tool oil down the tubes on the closer every day till you are done with the rest of the machine. My spindle motor is 5 hp but 3 would be ok if your diameters dont get too big and feedrates stay conservative. Terry - Original Message - From: Mike Cinquino mcinqu...@gmail.com To: emc-users@lists.sourceforge.net Cc: Sent: Thursday, April 19, 2012 8:23 PM Subject: [Emc-users] Hardinge HCNC Retrofit/Rebuild Hello, If anyone is interested I posted some picture of my HCNC project machine. I have started the retro rebuild process. Warning: the pictures my be disturbing to some machine lovers because of all the missing parts...:) http://www.conesusmachinetool.com/1/post/2012/04/hardinge-hcnc-lathe-rebuildretrofit.html Because of the parts I am missing I am going to try to use a DC motor (as suggest by someone on the IRC) or a stepper motor in place of the missing air motor on the tool changer. I am going to start there. I have the axis motors but not sure if I will use them yet. I can just as easily replace them. I am leaning toward Gecko servo drives so if I go that way I will probably replace them because of the voltage limit on those drives. I need a spindle motor. I have a PacSci AC servo motor (1.35KW) and drive. I have not run the numbers to see if it would be a good choice. My gut feeling is that it might be on the small side. If it is I will probably go to a 3phase 3HP with VFD? Not sure what HP it came with. Will build a custom enclosure similar to the mill enclosures I make. I also have the coolant tank and pump and one of the pictures shows a hydraulic panel? I have the over spindle mounted cut off slide? Was that hydraulic? It looks like the collet closer was pneumatic? I will update the blog as I make progress. I appreciate the feedback and help I have gotten so far and hopefully something from this project will benefit others in the future. Oh and of course it will be controlled by LinuxCNC... Mike -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Nonplanar arcs
I don't remember the complete syntax and symbols used but on my fanuc 15m control G68 sets the rotation angle of one rotary axis. You can use two G68 lines to rotate two rotary axes. The regular 2D code then works at the angle described by the G68 definitions. It takes some thought to get the rotations correct. It takes some thought and attention to follow the xyz zero position. G69 cancels the rotations. On Apr 19, 2012 10:58 PM, charles green xxzzb...@yahoo.com wrote: ..suppose you had a five axis millimg setup with the normal xyz plus alpha-beta rotation of the cutter rotation axis about a shperical center. then suppose that to take advantage of these spindle axes, you wanted to mill a planar facet on a part that was tipped at say five degrees to the x and five degrees to the y. the facet contains pockets with circular features that run normal to the tipped face, or circular bosses with tap bores running along their axis. it would be nice to rotate the entire coordinate system to align with some of the features of interest on a part that is otherwise already set up and positioned in the machine. another solution would be to accurately rotate the part about a and b and c axes, and just keep track of what that does to the xyz zero on the part, and then all the 2d gcode still applies. this is probably the more common of the five axis styles. maybe g16 a b c is an arbitrary interpolation plane for arcs, where abc are rotations relative to the abc origin (= the usual xyz directions)? xyzijk would have the usual meanings. maybe g15 p q r is an arbitrary x'y'z' coordinate system, where pqr is a unit vector relative to the usual xyz unit vector? xyzijk would be in the sense of the rotated x'y'z' coordinate system, and g16 would act on top of this new coordinate system. maybe g14 selects no preferred plane, and disallows g2/3 until g16-19 are set. maybe it also sets x'y'z' = xyz coordinates? --- On Thu, 4/19/12, Chris Radek ch...@timeguy.com wrote: From: Chris Radek ch...@timeguy.com Subject: Re: [Emc-users] Nonplanar arcs To: Enhanced Machine Controller (EMC) emc-users@lists.sourceforge.net Date: Thursday, April 19, 2012, 11:57 AM On Thu, Apr 19, 2012 at 09:45:42PM +0300, Viesturs L??cis wrote: Uhhh, You are right, halfcircles. All three points are on a straight line, around which the arc can freely rotate. I guess that this is special case (is there any other?), That is just the worst problem. Your system doesn't uniquely identify any arc. For every start, center, end points there are a pair of arcs that share the points. This is why we have G2/G3. If you don't have a normal vector you can't say which way is clockwise, so G2/G3 don't make sense. This is also a problem you get when you specify the arbitrary plane with three points, as was proposed by Ian M. The correct solution is probably to specify the plane's normal vector. While it's entirely possible to do, I doubt anyone would ever use this feature if someone did the work to implement it. Chris -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] That single channel digital pocket scope has arrived :(
On 19.04.12 12:25, gene heskett wrote: Ahh, but which sd* is it: From dmesg when I plug in the reader: [snipped uninformative dmesg output] Having a usb card reader with a small SD card in it, lying on the desk, I've just plugged it in for comparison with your tribulations. On ubuntu 10.04, I get: a) mount shows: /dev/sde1 on /media/6B36-55C9 type vfat \ (rw,nosuid,nodev,uhelper=udisks,uid=1000,gid=1000,shortname=mixed,dmask=0077,utf8=1,flush) b) dmesg includes the device as well: [ 1478.412932] sd 4:0:0:0: [sdc] Attached SCSI removable disk [ 1478.424578] sd 4:0:0:2: [sde] 60800 512-byte logical blocks: (31.1 MB/29.6 MiB) [ 1478.427254] sd 4:0:0:2: [sde] Write Protect is off [ 1478.427266] sd 4:0:0:2: [sde] Mode Sense: 03 00 00 00 [ 1478.427273] sd 4:0:0:2: [sde] Assuming drive cache: write through [ 1478.427551] sd 4:0:0:1: [sdd] Attached SCSI removable disk [ 1478.439869] sd 4:0:0:2: ioctl_internal_command return code = 807 [ 1478.439879]: Sense Key : Hardware Error [current] [ 1478.439888]: Add. Sense: No additional sense information [ 1478.446987] sd 4:0:0:2: [sde] Assuming drive cache: write through [ 1478.447006] sde: [ 1478.447151] sd 4:0:0:3: Attached scsi generic sg6 type 0 [ 1478.447502] sd 4:0:0:3: [sdf] Attached SCSI removable disk [ 1478.450015] sde1 In my experience (sample size == 2), 50% of card readers work with linux. ;) The rest are only good for recovering a connector or two for other uses. Fortunately they're fairly cheap, but in case the real ratio of duds is much higher, the AV Labs 70 in 1 usb 2.0 Card Reader Writer works for me. Hope you can find one that's not made by Murphy. Erik -- Leibowitz's Rule: When hammering a nail, you will never hit your finger if you hold the hammer with both hands. -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] That single channel digital pocket scope has arrived :(
On Thursday, April 19, 2012 11:07:08 PM Mark Cason did opine: On 04/19/2012 11:25 AM, gene heskett wrote: On Thursday, April 19, 2012 12:08:58 PM Mark Cason did opine: On 04/19/2012 10:15 AM, gene heskett wrote: On Thursday, April 19, 2012 10:34:37 AM Mark Wendt did opine: Humm, inserted into my reader, its presence is acknowledged, but its not accessible. The usb system issues a boatload of resets but never gets any farther than listing it as sdg, sdh, sdi, sdj. The reader itself indicates it is plugged in by turning on a lights up the whole room blue led Does anyone know what modules are needed to access an SD card while running linux? Cheers, Gene On any modern Linux OS, it should Just Work. There's been instances where flash drives had issues in linux, but worked perfectly well in Windows, due to software already installed on the drives. You can always try to reformat it from a terminal, using the command mkfs.vfat, and the location of your device. (/dev/sd?) Snip Plugging the whole thing into a direct usb port fiddles around trying to find something for a couple of minutes, but winds up looking like this in dmesg: ehci_hcd :00:02.1: port 5 full speed -- companion ehci_hcd :00:02.1: GetStatus port:5 status 003001 0 ACK POWER OWNER sig=se0 CONNECT hub 1-0:1.0: port 5 not reset yet, waiting 50ms hub 1-0:1.0: state 7 ports 10 chg evt 0020 ehci_hcd :00:02.1: GetStatus port:5 status 001002 0 ACK POWER sig=se0 CSC hub 1-0:1.0: logical disconnect on port 5 hub 1-0:1.0: state 7 ports 10 chg 0020 evt 0020 hub 1-0:1.0: port 5, status 0100, change , 12 Mb/s usb 1-5: USB disconnect, device number 53 usb 1-5: unregistering device usb 1-5: unregistering interface 1-5:1.0 usb 1-5: usb_disable_device nuking all URBs Thanks Cheers Mark, Gene My first rule of thumb, if it doesn't work with a hub, then try it directly. It looks like the USB port is not reading the drive correctly. Since this is a microSDHC, have you tried using another adapter to put it in? I've run into a similar problem when I used a different manufacturers adapter on one of my Sandisk cards. (I'm using a laptop, so the card reader is already built into my computer.) Also, have you tried running lsusb -vv? It wasn't there. What I did was take my card interface, and the card to the tv station where we plugged in into a W7 box. It never found the SDHC card. So Jim had a reader in another machine, which found it in 2 or 3 seconds. My reader wasn't SDHC compatible. The, re-reading the docs that came with the scope, it isn't compatible with SDHC, only SD. That comes in 2Gb max, and there are none in captivity within 50 miles of me. So I bought a new reader that claims it can do SDHC which is what I think is in my Nikon and came home, and have now ordered 2 of them from some schlock that insists on paypal. Cheers, Gene -- There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) My web page: http://coyoteden.dyndns-free.com:85/gene The Unixverse ends on Tue, 19 Jan 2038 03:14:07 + -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Nonplanar arcs
I know this is a serious topic but this happened to me on my 15m: G68 axis rotation M68 turns on the comveyor on this machine. Yeah you know what I did Some sadistic machine tool builder did that on purpose Terry - Original Message - From: Stuart Stevenson stus...@gmail.com To: Enhanced Machine Controller (EMC) emc-users@lists.sourceforge.net Cc: Sent: Thursday, April 19, 2012 11:13 PM Subject: Re: [Emc-users] Nonplanar arcs I don't remember the complete syntax and symbols used but on my fanuc 15m control G68 sets the rotation angle of one rotary axis. You can use two G68 lines to rotate two rotary axes. The regular 2D code then works at the angle described by the G68 definitions. It takes some thought to get the rotations correct. It takes some thought and attention to follow the xyz zero position. G69 cancels the rotations. On Apr 19, 2012 10:58 PM, charles green xxzzb...@yahoo.com wrote: ..suppose you had a five axis millimg setup with the normal xyz plus alpha-beta rotation of the cutter rotation axis about a shperical center. then suppose that to take advantage of these spindle axes, you wanted to mill a planar facet on a part that was tipped at say five degrees to the x and five degrees to the y. the facet contains pockets with circular features that run normal to the tipped face, or circular bosses with tap bores running along their axis. it would be nice to rotate the entire coordinate system to align with some of the features of interest on a part that is otherwise already set up and positioned in the machine. another solution would be to accurately rotate the part about a and b and c axes, and just keep track of what that does to the xyz zero on the part, and then all the 2d gcode still applies. this is probably the more common of the five axis styles. maybe g16 a b c is an arbitrary interpolation plane for arcs, where abc are rotations relative to the abc origin (= the usual xyz directions)? xyzijk would have the usual meanings. maybe g15 p q r is an arbitrary x'y'z' coordinate system, where pqr is a unit vector relative to the usual xyz unit vector? xyzijk would be in the sense of the rotated x'y'z' coordinate system, and g16 would act on top of this new coordinate system. maybe g14 selects no preferred plane, and disallows g2/3 until g16-19 are set. maybe it also sets x'y'z' = xyz coordinates? --- On Thu, 4/19/12, Chris Radek ch...@timeguy.com wrote: From: Chris Radek ch...@timeguy.com Subject: Re: [Emc-users] Nonplanar arcs To: Enhanced Machine Controller (EMC) emc-users@lists.sourceforge.net Date: Thursday, April 19, 2012, 11:57 AM On Thu, Apr 19, 2012 at 09:45:42PM +0300, Viesturs L??cis wrote: Uhhh, You are right, halfcircles. All three points are on a straight line, around which the arc can freely rotate. I guess that this is special case (is there any other?), That is just the worst problem. Your system doesn't uniquely identify any arc. For every start, center, end points there are a pair of arcs that share the points. This is why we have G2/G3. If you don't have a normal vector you can't say which way is clockwise, so G2/G3 don't make sense. This is also a problem you get when you specify the arbitrary plane with three points, as was proposed by Ian M. The correct solution is probably to specify the plane's normal vector. While it's entirely possible to do, I doubt anyone would ever use this feature if someone did the work to implement it. Chris -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- For Developers, A Lot Can
Re: [Emc-users] That single channel digital pocket scope has arrived :(
On Friday, April 20, 2012 12:32:56 AM Adrian Carter did opine: On 20 April 2012 01:38, gene heskett ghesk...@wdtv.com wrote: On Thursday, April 19, 2012 11:19:00 AM Adrian Carter did opine: Gene, Sorry to hear of the issues you had! I have been away from email today, so only just catching up - but glad to hear you got it sorted out in the end. Regards Adrian Ahh, the ghost re-appears! :) Yes, I think I have that problem solved but will need to get used to the function button, the +- and '||' and '||' marked buttons seem to be swapped now. But I bought a SanDisk 4Gb SD card for it last night, and which causes it to freeze up when one of those functions is selected, power switch seems to be the only 'get out' method. I now have that card plugged into my reader/writer, one of those that has a socket for any form factor from CF down to microsd, and its not accessible there either. The card interface turns on its device present led, but that is about it. Any clues on this? Wow you never get it easy do you :) Well I'm assuming you've checked the usual issues and that you are sure its not just a bad SD card despite it being new (I've had a few :( that or my DSLR camera enjoys eating them) and outside that I'd be guessing right now. Will have a poke around the Seeed forums and see if anything jumps out at me. Adrian Save your time Adrian, I found it. There are SD cards, and there are SDHC cards. Neither my old reader, nor this DSO Nano supports the SDHC protocol. I believe its a hardware limitation. Since SD cards are considered antiques these days, none are locally stocked, so I ordered a pair of the correct cards earlier this evening off the intertubes. And while I was in town, I bought a newer reader that supports them all (as of right now that is). ;-) Thanks Adrian. Cheers, Gene -- There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) My web page: http://coyoteden.dyndns-free.com:85/gene Refreshed by a brief blackout, I got to my feet and went next door. -- Martin Amis, _Money_ -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users Cheers, Gene -- There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) My web page: http://coyoteden.dyndns-free.com:85/gene Usage: fortune -P [-f] -a [xsz] Q: file [rKe9] -v6[+] file1 ... -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Nonplanar arcs
let the machine keep track of where the intial part origin goes when rotary axis moves with a macro that contains trig, the rotation centers of the machine setup, and g92s. then just do all the programming based on that single part origin. the gcode is then portable between different machine/rotary setups. sounds like the g68 might work like that. it works well for parts attached anywhere to a single rotary axis, using the rotary axis to index different angled faces. the programming is easy with the exception of remembering to choose an appropriate rapid plane for each face. --- On Thu, 4/19/12, Stuart Stevenson stus...@gmail.com wrote: From: Stuart Stevenson stus...@gmail.com Subject: Re: [Emc-users] Nonplanar arcs To: Enhanced Machine Controller (EMC) emc-users@lists.sourceforge.net Date: Thursday, April 19, 2012, 9:13 PM I don't remember the complete syntax and symbols used but on my fanuc 15m control G68 sets the rotation angle of one rotary axis. You can use two G68 lines to rotate two rotary axes. The regular 2D code then works at the angle described by the G68 definitions. It takes some thought to get the rotations correct. It takes some thought and attention to follow the xyz zero position. G69 cancels the rotations. On Apr 19, 2012 10:58 PM, charles green xxzzb...@yahoo.com wrote: ..suppose you had a five axis millimg setup with the normal xyz plus alpha-beta rotation of the cutter rotation axis about a shperical center. then suppose that to take advantage of these spindle axes, you wanted to mill a planar facet on a part that was tipped at say five degrees to the x and five degrees to the y. the facet contains pockets with circular features that run normal to the tipped face, or circular bosses with tap bores running along their axis. it would be nice to rotate the entire coordinate system to align with some of the features of interest on a part that is otherwise already set up and positioned in the machine. another solution would be to accurately rotate the part about a and b and c axes, and just keep track of what that does to the xyz zero on the part, and then all the 2d gcode still applies. this is probably the more common of the five axis styles. maybe g16 a b c is an arbitrary interpolation plane for arcs, where abc are rotations relative to the abc origin (= the usual xyz directions)? xyzijk would have the usual meanings. maybe g15 p q r is an arbitrary x'y'z' coordinate system, where pqr is a unit vector relative to the usual xyz unit vector? xyzijk would be in the sense of the rotated x'y'z' coordinate system, and g16 would act on top of this new coordinate system. maybe g14 selects no preferred plane, and disallows g2/3 until g16-19 are set. maybe it also sets x'y'z' = xyz coordinates? --- On Thu, 4/19/12, Chris Radek ch...@timeguy.com wrote: From: Chris Radek ch...@timeguy.com Subject: Re: [Emc-users] Nonplanar arcs To: Enhanced Machine Controller (EMC) emc-users@lists.sourceforge.net Date: Thursday, April 19, 2012, 11:57 AM On Thu, Apr 19, 2012 at 09:45:42PM +0300, Viesturs L??cis wrote: Uhhh, You are right, halfcircles. All three points are on a straight line, around which the arc can freely rotate. I guess that this is special case (is there any other?), That is just the worst problem. Your system doesn't uniquely identify any arc. For every start, center, end points there are a pair of arcs that share the points. This is why we have G2/G3. If you don't have a normal vector you can't say which way is clockwise, so G2/G3 don't make sense. This is also a problem you get when you specify the arbitrary plane with three points, as was proposed by Ian M. The correct solution is probably to specify the plane's normal vector. While it's entirely possible to do, I doubt anyone would ever use this feature if someone did the work to implement it. Chris -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net
Re: [Emc-users] Trajectory planning and other topics from a EMC(LinuxCNC) newbie (TheNewbie)
It seems to me that the likelihood of fixing all of the methods of gcode generation such that they don't generate short line segments is approximately zero. Also, it seems that even if a proprietary LinuxCNC gcode extension allowed arbitrary plane arcs, splines, etc. that the likelihood of CAM packages being able to make proper use of that is also approximately zero. Rather than trying to solve this problem in a million places not under our control, doesn't it make sense to try and solve it properly in one place and look more closely at using more than one line for look ahead? Of course I have no idea how hard this problem is, and since it has not yet been solved yet in LinuxCNC I presume it is significantly hard, but I am wondering what specifically makes it hard. Thanks, Scott -- For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
