Re: [Emc-users] Closed loop stepping system
Search for Leadshine closed loop stepper on YouTube. Looks like some very smooth and quiet operation from steppers. -- Precog is a next-generation analytics platform capable of advanced analytics on semi-structured data. The platform includes APIs for building apps and a phenomenal toolset for data science. Developers can use our toolset for easy data analysis visualization. Get a free account! http://www2.precog.com/precogplatform/slashdotnewsletter ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] : Which mini ITX board to choose? (Rudy du Preez)
Gene What I sometimes do is to take a piece of electrical wire and strip the insulation off. Then I split the insulation along the length and slip it over the sharp edge. You can glue it with some epoxy or the like. On 2013/04/11 12:16 AM, Gene Heskett wrote: On Wednesday 10 April 2013 18:12:55 Marius Liebenberg did opine: Gene, The pins on the MB is just a double header so you should be able to do that. I am looking at doing just that so I made a visit to the supplier and had a look at the MB to see how they do it. You could always make a little slot in the end plate of the PCI card or pop out one of the unused place holders on the back plate. Which is what I did do at one point but with a 50 pin scsi cable from a triple 82C55 based card, and the edges of the hole in the backplane were too sharp for comfort IMO. To be comfy, it would have needed an edge breaker strip installed. And those aren't commodity items here in the middle of WV. :) On 2013/04/10 05:43 PM, Gene Heskett wrote: On Wednesday 10 April 2013 11:40:26 Rudy du Preez did opine: The Intel D2800MT actually has a parallel port. It sits on the board and needs a ribbon cable extension. Can the ribbon cable be fed directly to a B.O.B. such as Leonardo's CNC4PC model C1G?, bypassing at least one set of db25's? Sounds cool if you can get the cable out of a box like the 350 mini itx box. I am currently running a Linuxcnc 2.5.2 on this board with two parports: one in the PCI-E slot and one on the ribbon cable. One is configured as out and the other as in. Rudy Cheers, Gene -- Regards / Groete Marius D. Liebenberg MasterCut cc Cel: +27 82 698 3251 Tel: +27 12 743 6064 Fax: +27 86 551 8029 Skype: marius_d.liebenberg Skype Me^(TM)! skype:marius_d.liebenberg?call Get Skype http://www.skype.com/go/download and call me for free. --- avast! Antivirus: Outbound message clean. Virus Database (VPS): 130410-2, 2013/04/10 Tested on: 2013/04/11 08:36:53 AM avast! - copyright (c) 1988-2013 AVAST Software. http://www.avast.com -- Precog is a next-generation analytics platform capable of advanced analytics on semi-structured data. The platform includes APIs for building apps and a phenomenal toolset for data science. Developers can use our toolset for easy data analysis visualization. Get a free account! http://www2.precog.com/precogplatform/slashdotnewsletter ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
[Emc-users] Routing cables out the back of a PC Re: : Which mini ITX board to choose? (Rudy du Preez)
Use the port connectors which used to come with later AT style and some ATX motherboards. Computers shops that have been around for a while should have a bunch of them if they haven't cleaned out their old stuff. Just be aware that the header pinouts on those used to be one way, then Intel decided, We're going to change the standards. and the rest of the PC industry went Eh, sure, whatever Intel says is what we'll go with. The shops may also have some dead I/O cards to remove slot brackets from, or slot brackets already on the port connectors that were to be used in cases without port knockouts. If you can't find any of those serial and parallel port connectors, you can make them from a solder cup style D connector, an IDC header connector and a length of ribbon cable. The benefit of DIY is you can make female DE-9 ports and wire male DB-25 ports for parallel instead of serial. Just make sure to label the nonstandard ones! As for boards to use for LinuxCNC, I wonder how a Gigabyte GA-MA78GM-S2H would do? It's not too old yet has one header for a parallel port and one header for a RS232 port. The connectors were optional extras, weren't in the box. I picked it up at a yard sale, new, never used, for six dollars. :-) Then I spent $50 on a 3.2 Ghz Phenom II X2 555 Socket AM3 CPU... If only it had an SB710 instead of SB700 chipset, I could unlock it to a quad core. The guy I bought it from had been running it that way. -- Precog is a next-generation analytics platform capable of advanced analytics on semi-structured data. The platform includes APIs for building apps and a phenomenal toolset for data science. Developers can use our toolset for easy data analysis visualization. Get a free account! http://www2.precog.com/precogplatform/slashdotnewsletter ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Closed loop stepping system
That's nice presentation, and exactly what I'm looking for to improve my two rotary axes with steppers... Search for Leadshine closed loop stepper on YouTube. Looks like some very smooth and quiet operation from steppers. -- Precog is a next-generation analytics platform capable of advanced analytics on semi-structured data. The platform includes APIs for building apps and a phenomenal toolset for data science. Developers can use our toolset for easy data analysis visualization. Get a free account! http://www2.precog.com/precogplatform/slashdotnewsletter ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] : Which mini ITX board to choose? (Rudy du Preez)
On Thursday 11 April 2013 08:39:43 Marius Liebenberg did opine: Gene What I sometimes do is to take a piece of electrical wire and strip the insulation off. Then I split the insulation along the length and slip it over the sharp edge. You can glue it with some epoxy or the like. I've done that too, but getting it to stay in position long enough for superglue to set can be a problem. The ready made nylon stuff is better, but usually formed for 16 gauge metal, not this razor sharp 28 gauge they use for backplates these days. Even running it out through a card slot, I usually try to put an extra wrap of scotch 88 tape on the edges. Paranoia I guess. Thanks. On 2013/04/11 12:16 AM, Gene Heskett wrote: On Wednesday 10 April 2013 18:12:55 Marius Liebenberg did opine: Gene, The pins on the MB is just a double header so you should be able to do that. I am looking at doing just that so I made a visit to the supplier and had a look at the MB to see how they do it. You could always make a little slot in the end plate of the PCI card or pop out one of the unused place holders on the back plate. Which is what I did do at one point but with a 50 pin scsi cable from a triple 82C55 based card, and the edges of the hole in the backplane were too sharp for comfort IMO. To be comfy, it would have needed an edge breaker strip installed. And those aren't commodity items here in the middle of WV. :) On 2013/04/10 05:43 PM, Gene Heskett wrote: On Wednesday 10 April 2013 11:40:26 Rudy du Preez did opine: The Intel D2800MT actually has a parallel port. It sits on the board and needs a ribbon cable extension. Can the ribbon cable be fed directly to a B.O.B. such as Leonardo's CNC4PC model C1G?, bypassing at least one set of db25's? Sounds cool if you can get the cable out of a box like the 350 mini itx box. I am currently running a Linuxcnc 2.5.2 on this board with two parports: one in the PCI-E slot and one on the ribbon cable. One is configured as out and the other as in. Rudy Cheers, Gene 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 is up! My views http://www.armchairpatriot.com/What%20Has%20America%20Become.shtml I'm reporting for duty as a modern person. I want to do the Latin Hustle now! A pen in the hand of this president is far more dangerous than a gun in the hands of 200 million law-abiding citizens. -- Precog is a next-generation analytics platform capable of advanced analytics on semi-structured data. The platform includes APIs for building apps and a phenomenal toolset for data science. Developers can use our toolset for easy data analysis visualization. Get a free account! http://www2.precog.com/precogplatform/slashdotnewsletter ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Closed loop stepping system
Thanks Gene, this has been a very enriching discussion. No plans still for the Hubles's mirror :). Cheers, Javier On Wed, Apr 10, 2013 at 7:37 PM, Gene Heskett ghesk...@wdtv.com wrote: On Wednesday 10 April 2013 13:01:29 Javier Ros did opine: This system http://www.automationtechnologiesinc .com/products-page/nema23-closed-loop-stepper-motor-system-hybrid-servo- kit/hybrid-servo-drive-kl-5080h Is apparently a stepper motor that is controlled as a brushless. Essentially a stepper is a brushless. This needs a encoder, probably one with a index pulse correctly positioned, so that the electronics can compute the switching accurately. This means, even if the control of the drive looks like a STEP DIR control, internally there are position and current loops, theoretically such a drive could offer, velocity and current control (I've not checked for the above reference). This means essentially that, the motor runs cooler, because only the required intensity is flowing in the motor, and not the maximum required intensity (the one that is controlled with the typical potentiometer in typical stepper drives). This means as well that the motor runs smoother, this must be most noticeable at low velocities, and finally that the positioning can be as precise as the encoder is. I regard of precision, note that a stepper, is not as precise as 3600/steps_per_revolution/microsteps, because microsteps don need to be equally spaced, even steps are not precise due to manufacturing (magnetic field) do not have to be equally spaced. In addition to this forces make that the motor is not centered at the center of the microstep. Let me fine tune this by pointing out that the stepper motor maker can, with access to the maps the controller uses to adjust its currents when microstepping, could be fine tuned such that at light loading, the microsteps can be pretty accurate. This of course means the motor and the controller must be calibrated to each other. That will be the makers job since few if any of us have the tools to do that, and it sure wouldn't be feasible economically for everyone to own their own stuff to do that. More just plain old comment: The noise would likely go down a bit, but since we aren't also throttling the current in many drivers (mine does after about a second of no motion, so mine only heat about 15F when idle), the motor is still going to run hot. The ideal situation would be by adjusting the overall currents to keep the motor within say 20%/microstep of the ideal microstepped position, but again this would require a high precision encoder, or some sort of magnetically detected feedback to detect the error in real time only use enough current to achieve that. But at that point, you may as well spend the money on a servo system, which may well be what this outfit is doing. Net cost will be similar. My current stepper setup, using 425oz motors on the lathe, was just under $100/axis. This is only a 252oz motor and costs USD 210/axis. I can't seem to justify the extra sheckel's for me. In comparison a brushless type encoder based drive for steeper can be as precise as the encoder, you know the actual position with the encoder position, although the position can be different of the commanded position, but you know the difference. The only limitations seem to be related to control at hih rpms, performance degrades in comparison with brushless. I would say that this is related to the higher pole count of the steeper,and the inherent dificulty to stablish intensity at high pole conmutation frecuency due to impedance, something that con be alleviated increaing voltage as much as possible.. In regard to this the error position, it can be even smaller in this brushless system because, as it runs cooler, you can allow for small duration current higher than the nominal. For a steeper you can not surpass the nominal value, not for the motor not for the electronics. Theoretically true. The motor can be banged with considerable overcurrent when it is lightly loaded and essentially exactly in position, but if half s step off or more due to heavy loading, then the rotor's magnetism could be effected, permanently damaging the motor. I've never run a system of this type, but I would love to use one of the MESA cards and brushless firmwares to test a such a setup (I'm interested in current control) if somebody with more experience thinks/knowns this is possible and not too difficult. Just using a double shaft stepper and a cheap encoder. I would love, to identify stepper cogging, and to software compensate for it. A moot point IMO when the gearing is such that 1 microstep is a fraction of a micron without resorting to a doubling of cost per axis. I haven't actually checked, as my step accuracy is the same on both axis's of the lathe, the x is a 2.5mm/turn screw, the z is 5,
Re: [Emc-users] Closed loop stepping system
Gene Heskett wrote: Somebody thinking outside the box, and making perfect sense. The only fly in the soup is the 10,000 step encoder, and servicing it at 200 rpS to get that 12,000 rpms If you run a stepper motor at 12,000 RPM, it will burn up in minutes. You can spin a typical stepper with the spindle motor, and above 1000 RPM it will get very hot with no current at all in the windings. That is all iron loss. 12,000 RPM will require insane voltages be applied to the drive, several hundred Volts. A typical stepper may generate 50 V at 1000 RPM, so that would require a 600 V supply just to equal the back EMF at 12K. Oh, but then cogoman said : the stepper motor could be designed with less steps per rev. Yes, then why make it a stepper at all? How about an 8-pole brushless servo motor? These work GREAT, used by Fanuc since the late 1980's, and now available from many sources. I make affordable servo amps for brushless motors, and have one on my minimill. You do need to get rotor position info from the motor, most small ones have Hall sensors that you connect to the servo amp. I use 500 cycle/rev encoders on mine, that is quite satisfactory. Jon -- Precog is a next-generation analytics platform capable of advanced analytics on semi-structured data. The platform includes APIs for building apps and a phenomenal toolset for data science. Developers can use our toolset for easy data analysis visualization. Get a free account! http://www2.precog.com/precogplatform/slashdotnewsletter ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Closed loop stepping system
On Thu, 11 Apr 2013, Jon Elson wrote: Date: Thu, 11 Apr 2013 11:32:55 -0500 From: Jon Elson el...@pico-systems.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] Closed loop stepping system Gene Heskett wrote: Somebody thinking outside the box, and making perfect sense. The only fly in the soup is the 10,000 step encoder, and servicing it at 200 rpS to get that 12,000 rpms If you run a stepper motor at 12,000 RPM, it will burn up in minutes. You can spin a typical stepper with the spindle motor, and above 1000 RPM it will get very hot with no current at all in the windings. That is all iron loss. 12,000 RPM will require insane voltages be applied to the drive, several hundred Volts. A typical stepper may generate 50 V at 1000 RPM, so that would require a 600 V supply just to equal the back EMF at 12K. Oh, but then cogoman said : the stepper motor could be designed with less steps per rev. Yes, then why make it a stepper at all? How about an 8-pole brushless servo motor? These work GREAT, used by Fanuc since the late 1980's, and now available from many sources. I make affordable servo amps for brushless motors, and have one on my minimill. You do need to get rotor position info from the motor, most small ones have Hall sensors that you connect to the servo amp. I use 500 cycle/rev encoders on mine, that is quite satisfactory. Jon The Leadshine closed loop step motors actually do have some advantages. because of the high number of poles (50 typically), when run in step motor mode the torque vs displacement curve is much steeper than a normal brushless motor which allows a clever hack when stationary. When staionary the motor can be run in step motor mode (radial pull vs tangential pull) with reduced current. This eliminates the +- a count or so jitter that full servo systems have when stationary (especially with static load) You still have the torque vs speed limits because of the number of poles and stepmotors even run as servos are not as efficent or as high performance as normal brushless motors but in the size ranges that make sense, closed loop stepper systems are very nice. -- Precog is a next-generation analytics platform capable of advanced analytics on semi-structured data. The platform includes APIs for building apps and a phenomenal toolset for data science. Developers can use our toolset for easy data analysis visualization. Get a free account! http://www2.precog.com/precogplatform/slashdotnewsletter ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users Peter Wallace Mesa Electronics (\__/) (='.'=) This is Bunny. Copy and paste bunny into your ()_() signature to help him gain world domination. -- Precog is a next-generation analytics platform capable of advanced analytics on semi-structured data. The platform includes APIs for building apps and a phenomenal toolset for data science. Developers can use our toolset for easy data analysis visualization. Get a free account! http://www2.precog.com/precogplatform/slashdotnewsletter ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] : Which mini ITX board to choose? (Rudy du Preez)
Gentlemen, I just put together an e350n with 4GB ram and 120GB SSD. The only bios play I did was to try to boot with a USB HDD. No joy there so I used a sata dvd to install. The all day servo thread latency settles around 9600 (an overnight run was 12000 in the morning). The all day base thread settles around 8700. This is with glxgears running and surfing the internet. Just information for your use. thanks Stuart On Thu, Apr 11, 2013 at 7:45 AM, Gene Heskett ghesk...@wdtv.com wrote: On Thursday 11 April 2013 08:39:43 Marius Liebenberg did opine: Gene What I sometimes do is to take a piece of electrical wire and strip the insulation off. Then I split the insulation along the length and slip it over the sharp edge. You can glue it with some epoxy or the like. I've done that too, but getting it to stay in position long enough for superglue to set can be a problem. The ready made nylon stuff is better, but usually formed for 16 gauge metal, not this razor sharp 28 gauge they use for backplates these days. Even running it out through a card slot, I usually try to put an extra wrap of scotch 88 tape on the edges. Paranoia I guess. Thanks. On 2013/04/11 12:16 AM, Gene Heskett wrote: On Wednesday 10 April 2013 18:12:55 Marius Liebenberg did opine: Gene, The pins on the MB is just a double header so you should be able to do that. I am looking at doing just that so I made a visit to the supplier and had a look at the MB to see how they do it. You could always make a little slot in the end plate of the PCI card or pop out one of the unused place holders on the back plate. Which is what I did do at one point but with a 50 pin scsi cable from a triple 82C55 based card, and the edges of the hole in the backplane were too sharp for comfort IMO. To be comfy, it would have needed an edge breaker strip installed. And those aren't commodity items here in the middle of WV. :) On 2013/04/10 05:43 PM, Gene Heskett wrote: On Wednesday 10 April 2013 11:40:26 Rudy du Preez did opine: The Intel D2800MT actually has a parallel port. It sits on the board and needs a ribbon cable extension. Can the ribbon cable be fed directly to a B.O.B. such as Leonardo's CNC4PC model C1G?, bypassing at least one set of db25's? Sounds cool if you can get the cable out of a box like the 350 mini itx box. I am currently running a Linuxcnc 2.5.2 on this board with two parports: one in the PCI-E slot and one on the ribbon cable. One is configured as out and the other as in. Rudy Cheers, Gene 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 is up! My views http://www.armchairpatriot.com/What%20Has%20America%20Become.shtml I'm reporting for duty as a modern person. I want to do the Latin Hustle now! A pen in the hand of this president is far more dangerous than a gun in the hands of 200 million law-abiding citizens. -- Precog is a next-generation analytics platform capable of advanced analytics on semi-structured data. The platform includes APIs for building apps and a phenomenal toolset for data science. Developers can use our toolset for easy data analysis visualization. Get a free account! http://www2.precog.com/precogplatform/slashdotnewsletter ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- dos centavos -- Precog is a next-generation analytics platform capable of advanced analytics on semi-structured data. The platform includes APIs for building apps and a phenomenal toolset for data science. Developers can use our toolset for easy data analysis visualization. Get a free account! http://www2.precog.com/precogplatform/slashdotnewsletter ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Poor CV
On 4/10/2013 5:01 PM, andy pugh wrote: On 10 April 2013 21:50, dave dengv...@charter.net wrote: No panacea anywhere in sight. Something I saw somewhere on the Internet (possibly a link from mah) was an article about different approaches. One very interesting idea was that every move as well as being an end-point also includes an end velocity I think that these end velocities need to propagate backwards back up the queue. While we are looking at this, we should be sure to consider adding jerk limits to the system. Since computers are (approximately) infinitely fast and have infinite memory, we should be able to look ahead to the next stop point (which might be the end of the program). I don't think this is rocket science. (Having worked on the Lunar Module project, I have a chance of recognizing rocket science.) Ken -- Precog is a next-generation analytics platform capable of advanced analytics on semi-structured data. The platform includes APIs for building apps and a phenomenal toolset for data science. Developers can use our toolset for easy data analysis visualization. Get a free account! http://www2.precog.com/precogplatform/slashdotnewsletter ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Poor CV
Ah! your timing is impeccable. I just sent some references to Kent with hope they will get added to the wiki. Dave On Thu, 2013-04-11 at 18:56 -0400, Kenneth Lerman wrote: On 4/10/2013 5:01 PM, andy pugh wrote: On 10 April 2013 21:50, dave dengv...@charter.net wrote: No panacea anywhere in sight. Something I saw somewhere on the Internet (possibly a link from mah) was an article about different approaches. One very interesting idea was that every move as well as being an end-point also includes an end velocity I think that these end velocities need to propagate backwards back up the queue. While we are looking at this, we should be sure to consider adding jerk limits to the system. Since computers are (approximately) infinitely fast and have infinite memory, we should be able to look ahead to the next stop point (which might be the end of the program). I don't think this is rocket science. (Having worked on the Lunar Module project, I have a chance of recognizing rocket science.) Ken -- Precog is a next-generation analytics platform capable of advanced analytics on semi-structured data. The platform includes APIs for building apps and a phenomenal toolset for data science. Developers can use our toolset for easy data analysis visualization. Get a free account! http://www2.precog.com/precogplatform/slashdotnewsletter ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- Precog is a next-generation analytics platform capable of advanced analytics on semi-structured data. The platform includes APIs for building apps and a phenomenal toolset for data science. Developers can use our toolset for easy data analysis visualization. Get a free account! http://www2.precog.com/precogplatform/slashdotnewsletter ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Poor CV
On 11 April 2013 23:56, Kenneth Lerman kenneth.ler...@se-ltd.com wrote: While we are looking at this, we should be sure to consider adding jerk limits to the system. I don't think this is rocket science. But then, neither is rocket science: http://youtu.be/THNPmhBl-8I I have tried writing a jerk-limited trajectory planner, there are complexities. It is possibly fairly easy for G-code, but on-the-fly calculations for jogging are a bit more tricky. -- atp If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto -- Precog is a next-generation analytics platform capable of advanced analytics on semi-structured data. The platform includes APIs for building apps and a phenomenal toolset for data science. Developers can use our toolset for easy data analysis visualization. Get a free account! http://www2.precog.com/precogplatform/slashdotnewsletter ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Poor CV
On Thu, 2013-04-11 at 18:56 -0400, Kenneth Lerman wrote: On 4/10/2013 5:01 PM, andy pugh wrote: On 10 April 2013 21:50, dave dengv...@charter.net wrote: No panacea anywhere in sight. Something I saw somewhere on the Internet (possibly a link from mah) was an article about different approaches. One very interesting idea was that every move as well as being an end-point also includes an end velocity I think that these end velocities need to propagate backwards back up the queue. While we are looking at this, we should be sure to consider adding jerk limits to the system. Since computers are (approximately) infinitely fast and have infinite memory, we should be able to look ahead to the next stop point (which might be the end of the program). H! This sounds like and idealized op amp: infinite input impedance and freq response and zero output impedance. ;-) I don't think this is rocket science. (Having worked on the Lunar Module project, I have a chance of recognizing rocket science.) Ken I can't even come close. The closest I got was doing x-ray on the propellant loading system on the Atlas (Fairchild AFB) and Titan ( Larson AFB). These were jobs between a school year and then after graduation while waiting for the job in bio-physics to open at WSU. Naturally, this got interrupted by the idiots building the Berlin Wall and the subsequent panic here. If your body temp was somewhere between 35 C and 41 C you got drafted. ;-) Dave -- Precog is a next-generation analytics platform capable of advanced analytics on semi-structured data. The platform includes APIs for building apps and a phenomenal toolset for data science. Developers can use our toolset for easy data analysis visualization. Get a free account! http://www2.precog.com/precogplatform/slashdotnewsletter ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- Precog is a next-generation analytics platform capable of advanced analytics on semi-structured data. The platform includes APIs for building apps and a phenomenal toolset for data science. Developers can use our toolset for easy data analysis visualization. Get a free account! http://www2.precog.com/precogplatform/slashdotnewsletter ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
[Emc-users] OT: Rocket science Re: Poor CV
--- On Thu, 4/11/13, andy pugh bodge...@gmail.com wrote: From: andy pugh bodge...@gmail.com Subject: Re: [Emc-users] Poor CV To: Enhanced Machine Controller (EMC) emc-users@lists.sourceforge.net Date: Thursday, April 11, 2013, 5:42 PM On 11 April 2013 23:56, Kenneth Lerman kenneth.ler...@se-ltd.com wrote: While we are looking at this, we should be sure to consider adding jerk limits to the system. I don't think this is rocket science. But then, neither is rocket science: http://youtu.be/THNPmhBl-8I And one for people who think the moon landings were fake. ;-) http://www.youtube.com/watch?v=P6MOnehCOUw -- Precog is a next-generation analytics platform capable of advanced analytics on semi-structured data. The platform includes APIs for building apps and a phenomenal toolset for data science. Developers can use our toolset for easy data analysis visualization. Get a free account! http://www2.precog.com/precogplatform/slashdotnewsletter ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] OT: Rocket science Re: Poor CV
Of course we landed on the moon silly.right?! LOL Pete On Thu, Apr 11, 2013 at 9:33 PM, Gregg Eshelman g_ala...@yahoo.com wrote: --- On Thu, 4/11/13, andy pugh bodge...@gmail.com wrote: From: andy pugh bodge...@gmail.com Subject: Re: [Emc-users] Poor CV To: Enhanced Machine Controller (EMC) emc-users@lists.sourceforge.net Date: Thursday, April 11, 2013, 5:42 PM On 11 April 2013 23:56, Kenneth Lerman kenneth.ler...@se-ltd.com wrote: While we are looking at this, we should be sure to consider adding jerk limits to the system. I don't think this is rocket science. But then, neither is rocket science: http://youtu.be/THNPmhBl-8I And one for people who think the moon landings were fake. ;-) http://www.youtube.com/watch?v=P6MOnehCOUw -- Precog is a next-generation analytics platform capable of advanced analytics on semi-structured data. The platform includes APIs for building apps and a phenomenal toolset for data science. Developers can use our toolset for easy data analysis visualization. Get a free account! http://www2.precog.com/precogplatform/slashdotnewsletter ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- Precog is a next-generation analytics platform capable of advanced analytics on semi-structured data. The platform includes APIs for building apps and a phenomenal toolset for data science. Developers can use our toolset for easy data analysis visualization. Get a free account! http://www2.precog.com/precogplatform/slashdotnewsletter ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
[Emc-users] A project I want to do on a CNC mill
I'd like to get the exact dimensions for the triangle pattern used in the wall and floor panels of Skylab. Looks like there are round holes, possibly threaded, where the triangle holes meet. Why that pattern? Because it's an interesting design and looks like it could be useful for other purposes, especially if the round holes are threaded. Anyone live near the Air and Space Museum? Would they allow someone in with a digital caliper to take measurements? The only other places I know of that may have those panels are the two Skylab simulators, if they were built to fully duplicate the two built for launching. -- Precog is a next-generation analytics platform capable of advanced analytics on semi-structured data. The platform includes APIs for building apps and a phenomenal toolset for data science. Developers can use our toolset for easy data analysis visualization. Get a free account! http://www2.precog.com/precogplatform/slashdotnewsletter ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] A project I want to do on a CNC mill
just get a picture with something of KNOWN size in it raster it in a vector program ( photoshop will do this ) import to autocad as dxf, measure known point to point divide known measurement by measurement made in autocad then rescale to the quotient . trim all but desired out of dxf . import to mastercam write program make :) now how to do this with all linux programs well i havent got there yet but when i do i will swear off bill gates forever:) note perpendicularity of the photo is very crucial to get accurate scaling this can be used with any photo sometimes to an accuracy of a couple of thousandths depending on perpendicularity and the accuracy of the known measured item On Thu, Apr 11, 2013 at 9:49 PM, Gregg Eshelman g_ala...@yahoo.com wrote: I'd like to get the exact dimensions for the triangle pattern used in the wall and floor panels of Skylab. Looks like there are round holes, possibly threaded, where the triangle holes meet. Why that pattern? Because it's an interesting design and looks like it could be useful for other purposes, especially if the round holes are threaded. Anyone live near the Air and Space Museum? Would they allow someone in with a digital caliper to take measurements? The only other places I know of that may have those panels are the two Skylab simulators, if they were built to fully duplicate the two built for launching. -- Precog is a next-generation analytics platform capable of advanced analytics on semi-structured data. The platform includes APIs for building apps and a phenomenal toolset for data science. Developers can use our toolset for easy data analysis visualization. Get a free account! http://www2.precog.com/precogplatform/slashdotnewsletter ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- jeremy youngs -- Precog is a next-generation analytics platform capable of advanced analytics on semi-structured data. The platform includes APIs for building apps and a phenomenal toolset for data science. Developers can use our toolset for easy data analysis visualization. Get a free account! http://www2.precog.com/precogplatform/slashdotnewsletter ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Closed loop stepping system
On Thursday 11 April 2013 22:13:10 Jon Elson did opine: Gene Heskett wrote: Somebody thinking outside the box, and making perfect sense. The only fly in the soup is the 10,000 step encoder, and servicing it at 200 rpS to get that 12,000 rpms If you run a stepper motor at 12,000 RPM, it will burn up in minutes. You can spin a typical stepper with the spindle motor, and above 1000 RPM it will get very hot with no current at all in the windings. That is all iron loss. 12,000 RPM will require insane voltages be applied to the drive, several hundred Volts. A typical stepper may generate 50 V at 1000 RPM, so that would require a 600 V supply just to equal the back EMF at 12K. And I never considered the iron loses Jon, but you are dead on. Oh, but then cogoman said : the stepper motor could be designed with less steps per rev. Yes, then why make it a stepper at all? How about an 8-pole brushless servo motor? These work GREAT, used by Fanuc since the late 1980's, and now available from many sources. I make affordable servo amps for brushless motors, and have one on my minimill. You do need to get rotor position info from the motor, most small ones have Hall sensors that you connect to the servo amp. I use 500 cycle/rev encoders on mine, that is quite satisfactory. Jon That also makes great sense as long as its economical enough to do. 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 is up! My views http://www.armchairpatriot.com/What%20Has%20America%20Become.shtml Evil isn't all bad. A pen in the hand of this president is far more dangerous than a gun in the hands of 200 million law-abiding citizens. -- Precog is a next-generation analytics platform capable of advanced analytics on semi-structured data. The platform includes APIs for building apps and a phenomenal toolset for data science. Developers can use our toolset for easy data analysis visualization. Get a free account! http://www2.precog.com/precogplatform/slashdotnewsletter ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] A project I want to do on a CNC mill
This seems to have been recently scanned, found it on Wikipedia. Isogrid hadn't turned up in my previous searches for this. Isogrid Design Handbook, NASA CR-124075, McDonnell Douglas, 1973 http://femci.gsfc.nasa.gov/Isogrid/NASA-CR-124075_Isogrid_Design.pdf And skipping through a tone of theory, math, more math, lots more math and other 'this is how we do it' stuff... Page 42 has the dimensions of the panels as used on Skylab! That would be so easy to have cut on a water jet. When were those invented? I'd expect the originals to have been cut out with an NC mill, which would've converted quite a lot of the plate to chips. --- On Thu, 4/11/13, jeremy youngs jcyoung...@gmail.com wrote: From: jeremy youngs jcyoung...@gmail.com Subject: Re: [Emc-users] A project I want to do on a CNC mill To: Enhanced Machine Controller (EMC) emc-users@lists.sourceforge.net Date: Thursday, April 11, 2013, 8:10 PM just get a picture with something of KNOWN size in it raster it in a vector program ( photoshop will do this ) import to autocad as dxf, measure known point to point divide known measurement by measurement made in autocad then rescale to the quotient . trim all but desired out of dxf . import to mastercam write program make :) now how to do this with all linux programs well i havent got there yet but when i do i will swear off bill gates forever:) note perpendicularity of the photo is very crucial to get accurate scaling this can be used with any photo sometimes to an accuracy of a couple of thousandths depending on perpendicularity and the accuracy of the known measured item On Thu, Apr 11, 2013 at 9:49 PM, Gregg Eshelman g_ala...@yahoo.com wrote: I'd like to get the exact dimensions for the triangle pattern used in the wall and floor panels of Skylab. Looks like there are round holes, possibly threaded, where the triangle holes meet. Why that pattern? Because it's an interesting design and looks like it could be useful for other purposes, especially if the round holes are threaded. Anyone live near the Air and Space Museum? Would they allow someone in with a digital caliper to take measurements? The only other places I know of that may have those panels are the two Skylab simulators, if they were built to fully duplicate the two built for launching. -- Precog is a next-generation analytics platform capable of advanced analytics on semi-structured data. The platform includes APIs for building apps and a phenomenal toolset for data science. Developers can use our toolset for easy data analysis visualization. Get a free account! http://www2.precog.com/precogplatform/slashdotnewsletter ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Poor CV
On 4/11/2013 6:56 PM, Kenneth Lerman wrote: I don't think this is rocket science. (Having worked on the Lunar Module project, I have a chance of recognizing rocket science.) Come on, Ken, the rocket-science part is dead easy. When you say F=ma you've said it all. Rocket engineering, on the other hand, is the famous horse of another color. Even with all the recent Discovery and History Channel shows about the manned lunar landing program to remind them, it's hard for most folk to understand all the blood, sweat, and tears (and fears) that went into the manned lunar landing program. Regards, Kent -- Precog is a next-generation analytics platform capable of advanced analytics on semi-structured data. The platform includes APIs for building apps and a phenomenal toolset for data science. Developers can use our toolset for easy data analysis visualization. Get a free account! http://www2.precog.com/precogplatform/slashdotnewsletter ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] A project I want to do on a CNC mill
IT LOOKS TREMENDOUSLY STRONG AND AGREE IT COULD BE USEFUL On Thu, Apr 11, 2013 at 10:36 PM, Gregg Eshelman g_ala...@yahoo.com wrote: This seems to have been recently scanned, found it on Wikipedia. Isogrid hadn't turned up in my previous searches for this. Isogrid Design Handbook, NASA CR-124075, McDonnell Douglas, 1973 http://femci.gsfc.nasa.gov/Isogrid/NASA-CR-124075_Isogrid_Design.pdf And skipping through a tone of theory, math, more math, lots more math and other 'this is how we do it' stuff... Page 42 has the dimensions of the panels as used on Skylab! That would be so easy to have cut on a water jet. When were those invented? I'd expect the originals to have been cut out with an NC mill, which would've converted quite a lot of the plate to chips. --- On Thu, 4/11/13, jeremy youngs jcyoung...@gmail.com wrote: From: jeremy youngs jcyoung...@gmail.com Subject: Re: [Emc-users] A project I want to do on a CNC mill To: Enhanced Machine Controller (EMC) emc-users@lists.sourceforge.net Date: Thursday, April 11, 2013, 8:10 PM just get a picture with something of KNOWN size in it raster it in a vector program ( photoshop will do this ) import to autocad as dxf, measure known point to point divide known measurement by measurement made in autocad then rescale to the quotient . trim all but desired out of dxf . import to mastercam write program make :) now how to do this with all linux programs well i havent got there yet but when i do i will swear off bill gates forever:) note perpendicularity of the photo is very crucial to get accurate scaling this can be used with any photo sometimes to an accuracy of a couple of thousandths depending on perpendicularity and the accuracy of the known measured item On Thu, Apr 11, 2013 at 9:49 PM, Gregg Eshelman g_ala...@yahoo.com wrote: I'd like to get the exact dimensions for the triangle pattern used in the wall and floor panels of Skylab. Looks like there are round holes, possibly threaded, where the triangle holes meet. Why that pattern? Because it's an interesting design and looks like it could be useful for other purposes, especially if the round holes are threaded. Anyone live near the Air and Space Museum? Would they allow someone in with a digital caliper to take measurements? The only other places I know of that may have those panels are the two Skylab simulators, if they were built to fully duplicate the two built for launching. -- Precog is a next-generation analytics platform capable of advanced analytics on semi-structured data. The platform includes APIs for building apps and a phenomenal toolset for data science. Developers can use our toolset for easy data analysis visualization. Get a free account! http://www2.precog.com/precogplatform/slashdotnewsletter ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- jeremy youngs -- Precog is a next-generation analytics platform capable of advanced analytics on semi-structured data. The platform includes APIs for building apps and a phenomenal toolset for data science. Developers can use our toolset for easy data analysis visualization. Get a free account! http://www2.precog.com/precogplatform/slashdotnewsletter ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Which mini ITX board to choose?
On 4/9/2013 12:06 PM, Jon Elson wrote: --- On Tue, 4/9/13, Viesturs Lācisviesturs.la...@gmail.com wrote: clip It has been discussed many times on this list that there is only one or two pci-to-parport cards out there that do actually work in EPP mode. All the others do so only in theory and docs, not in reality. I think Viesturs is overstating the problems with these plug-in cards. Yes, there are several old ones that definitely don't work, and one where the manufacturer of the chip even admits that it doesn't work. Most on-motherboard ports work fine, as long as a little BIOS bug is worked around, and as far as I know all LinuxCNC 2.4 and later drivers know how to do this. So, that problem should no longer be any problem. (I sometimes run into this when running diagnostics on EPP-attached hardware. If the diags only work after running LinuxCNC, that makes it clear.) Hopefully we can assemble a list of boards and parport chips known to work and make that available on the wiki. Jon -- I haven't had a problem with the D525MW cards running the onboard LPT port in EPP mode.. at least not with the last three that I used. Dave -- Precog is a next-generation analytics platform capable of advanced analytics on semi-structured data. The platform includes APIs for building apps and a phenomenal toolset for data science. Developers can use our toolset for easy data analysis visualization. Get a free account! http://www2.precog.com/precogplatform/slashdotnewsletter ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] A project I want to do on a CNC mill
I've found an error in one of the dimensions. The radius of the points of the triangles is given as 0.228 inch but that's impossible with the diameter of the holes at 0.438. Fitting a 0.228 radius tangent to the 0.070 thick bars makes it intersect the holes. Oops! Someone didn't sanity check the drawing... Changing the tip radius to the same as the hole diameter makes the design match the drawing. Alternatively, it could be the web bar thickness dimension is wrong, but they'd have to be a lot thicker and thus heavier to make the 0.228 triangle tip radius work. The bottom of the 8 is cut off so I figured it might be 0.338 but that's still too small. I'll go with 0.438 on them because it looks more like the drawing and photos of the grids. Perhaps this was McDonnell Douglas being like DaVinci, putting a deliberate error into a drawing not intended as a manufacturing document. Or it could be a typo, someone hit a 4 instead of a 3. Whatever the reason, proofreaders missed it. Proofreading, not like it's rocket science, eh? Should have a 3D model done in a few... --- On Thu, 4/11/13, jeremy youngs jcyoung...@gmail.com wrote: From: jeremy youngs jcyoung...@gmail.com Subject: Re: [Emc-users] A project I want to do on a CNC mill To: Enhanced Machine Controller (EMC) emc-users@lists.sourceforge.net Date: Thursday, April 11, 2013, 8:49 PM IT LOOKS TREMENDOUSLY STRONG AND AGREE IT COULD BE USEFUL On Thu, Apr 11, 2013 at 10:36 PM, Gregg Eshelman g_ala...@yahoo.com wrote: This seems to have been recently scanned, found it on Wikipedia. Isogrid hadn't turned up in my previous searches for this. Isogrid Design Handbook, NASA CR-124075, McDonnell Douglas, 1973 http://femci.gsfc.nasa.gov/Isogrid/NASA-CR-124075_Isogrid_Design.pdf And skipping through a tone of theory, math, more math, lots more math and other 'this is how we do it' stuff... Page 42 has the dimensions of the panels as used on Skylab! That would be so easy to have cut on a water jet. When were those invented? I'd expect the originals to have been cut out with an NC mill, which would've converted quite a lot of the plate to chips. -- Precog is a next-generation analytics platform capable of advanced analytics on semi-structured data. The platform includes APIs for building apps and a phenomenal toolset for data science. Developers can use our toolset for easy data analysis visualization. Get a free account! http://www2.precog.com/precogplatform/slashdotnewsletter ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Closed loop stepping system
Gene Heskett wrote: And I never considered the iron loses Jon, but you are dead on. Mariss Freimanis of Gecko describes some torture tests he did years ago and reported this. I make affordable servo amps for brushless motors, and have one on my minimill. You do need to get rotor position info from the motor, most small ones have Hall sensors that you connect to the servo amp. I use 500 cycle/rev encoders on mine, that is quite satisfactory. Jon That also makes great sense as long as its economical enough to do. The Gecko 201 series sells for $114, my brushless servo amp sells for $150, for 20 A at 120 V. Not vastly more expensive than a good stepper drive. Of course you need a PWM generator to run my servo amp, but then you need a hardware step generator to get full performance out of a microstepped stepper motor, too. Jon -- Precog is a next-generation analytics platform capable of advanced analytics on semi-structured data. The platform includes APIs for building apps and a phenomenal toolset for data science. Developers can use our toolset for easy data analysis visualization. Get a free account! http://www2.precog.com/precogplatform/slashdotnewsletter ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Closed loop stepping system
On Friday 12 April 2013 00:56:36 Jon Elson did opine: Gene Heskett wrote: And I never considered the iron loses Jon, but you are dead on. Mariss Freimanis of Gecko describes some torture tests he did years ago and reported this. Humm, now that you mention that, I read something similar on the net a few years agom from somebody at Gecko. Could have been the same person I'd have to assume. I make affordable servo amps for brushless motors, and have one on my minimill. You do need to get rotor position info from the motor, most small ones have Hall sensors that you connect to the servo amp. I use 500 cycle/rev encoders on mine, that is quite satisfactory. Jon That also makes great sense as long as its economical enough to do. The Gecko 201 series sells for $114, my brushless servo amp sells for $150, for 20 A at 120 V. Which is 17 amps more than my lathe spindle has. I wonder if that could make me a REAL variable speed spindle. This one runs out of steam when the steel is above 5/8 in diameter. Supposedly a 250 watt motor, older 7zx12. I'd like to take it up to shaving 1.75 to 2 stock. Could that reverse w/o needing to toggle a 4pdt relay? Not vastly more expensive than a good stepper drive. Of course you need a PWM generator to run my servo amp, but then you need a hardware step generator to get full performance out of a microstepped stepper motor, too. True, if you can find the voltage for the motors. I hate paying 150-200 for a big linear when I can cobble something up out of the surplus catalogs for 1/3rd of that. Unforch, suitable transformers seem to be getting rarer as time goes by. The gears are turning on that spindle idea though. :) Jon 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 is up! My views http://www.armchairpatriot.com/What%20Has%20America%20Become.shtml If you can, help others. If you can't, at least don't hurt others. -- the Dalai Lama A pen in the hand of this president is far more dangerous than a gun in the hands of 200 million law-abiding citizens. -- Precog is a next-generation analytics platform capable of advanced analytics on semi-structured data. The platform includes APIs for building apps and a phenomenal toolset for data science. Developers can use our toolset for easy data analysis visualization. Get a free account! http://www2.precog.com/precogplatform/slashdotnewsletter ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
[Emc-users] Skylab isogrid shape files to download.
Here's the files to download. http://www.PartsByEMC.com/pub/Skylab-isogrid-panel.jpg http://www.PartsByEMC.com/pub/Skylab-isogrid-unit.zip 3D Formats included, COB, IGS, DXF, SAT 2D Format DWG I made one star unit with the arms long enough to overlap. There's a text file in the ZIP with some info and the dimensions to lay out an array of these units to join into a single object. Now you have something different to mill. -- Precog is a next-generation analytics platform capable of advanced analytics on semi-structured data. The platform includes APIs for building apps and a phenomenal toolset for data science. Developers can use our toolset for easy data analysis visualization. Get a free account! http://www2.precog.com/precogplatform/slashdotnewsletter ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
