[Emc-users] PII machine
Hi list Am planning a 1.5m x 1.5m gantry style woodwork router. I have an old PII computer running at 222 hz. I have loaded ubuntu + emc, but can you tell me if I will be able to use it n a fairly basic router set up. Thanks for your recent answers Aaron -- Powered by Outblaze - This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now http://get.splunk.com/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
[Emc-users] Fw: [ emc-Bugs-1743942 ] MDI command in estop-reset runs in machine-on
Hello, Pete brings up an interesting point. Is it allowed to issue some MDI commands while in e-stop reset or even e-stop mode? AXIS (the GUI) simply disables MDI while machine is not switched on. TkEMC relies on task to do the right thing, and enables MDI and allows users to send MDI commands, and task then discards the ones that are not allowed. What do you (CNC users ;) think should be the reasonable thing to do while the machine is not switched on? I can see valid reasons to do both approaches: some M-commands might be usefull while in E-stop .. to make some clampings move, activate things, etc. Otoh one might argue that while e-stop nothing is allowed to move/change. Awaiting your input. Regards, Alex - Original Message - From: SourceForge.net [EMAIL PROTECTED] Subject: [ emc-Bugs-1743942 ] MDI command in estop-reset runs in machine-on Bugs item #1743942, was opened at 2007-06-26 18:25 https://sourceforge.net/tracker/?func=detailatid=106744aid=1743942group_id=6744 If an MDI command is issued in the estop-reset state, it is executed when the machine-on state is entered. I don't think entering the machine-on state should cause any motion or other type of command to execute. Any MDI commands issued in the estop-reset state should be ignored. -- Comment By: Pete Vavaroutsos (petev) Date: 2007-08-06 00:11 No, the behavior is different with the current CVS/trunk build. An error is given that says the machine must be enabled in coord mode when an MDI linear move command is issued in the e-stop reset state. However, commands like M3 are exectured immediately in MDI mode when in the e-stop reset state. Try the following: 1) Start a sim session using tkemc. 2) Get to machine on and home all axis. 3) Switch to MDI mode. 4) Change to machine off state. 5) Issue M3 in the MDI entry box. - This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now http://get.splunk.com/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] USB Wireless Network Steppers with encoders?
Hi there, Would my EMC2 system work with USB wireless networking? I'm thinking of this because I could connect the USB wireless adapter to a USB extension and position it for better reception. I'm just not sure if it would work on my Ubuntu Linux EMC2 system. Another option would be a PCI card and an external antenna with cable. both should work. However, there is no guarantee that you'll get one of the supported hardware cards. It would be best to search around wiki.ubuntu.com and around google. a list of USB wireless devices: http://at76c503a.berlios.de/devices.html Also, after getting to play with hal configurations a bit, It seems like it wouldn't be too difficult to get steppers working with encoder feedback. If you would set up a pid loop = frequency generator and configure velocity feed forward to run the steppers at the commanded velocity, then pid gains could be set to take care of position deviations. This would be useful in detection and correction of lost steps for one. It would also give you the ability to connect encoders directly to lead screws or use linear encoders for actual position feedback. It seems like this would be a little more to set up than just plain open loop steppers but shouldn't be much more difficult than setting up a servo system. I don't think I've ever heard of a stepper based system that is capable of positioning from linear scales. That should take care of lost steps, lead screw errors, minor amounts of backlash, etc. it shouldn't be too hard to set things up as you described them above. but there is one thing you need to remember. steppers usually have problems going at higher speeds (torques goes down). so if you start cutting at a too high feedrate, it might get behind the cut. the PID will see that and react, command the steppers even faster, which will most likely lead to even more problems. just my .02$ Regards, Alex - This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now http://get.splunk.com/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] PII machine
Hi Aaron like in the Wiki described, about 500 MHz are O.K. my experiment with slow computers are: 450 Mhz PIII with 512 MB RAM: Installation works (256 MB RAM failed to install), takes time, Simulation O.K., but Halmeter and other diagnostics painful slow. 1.1 GHz AMD, 512 MB RAM works fine. My recommandation 6-800 MHz are O.K., if You like me without Linux experience. Hansjakob Am 06.08.2007 um 08:58 schrieb aaron Moore: Hi list Am planning a 1.5m x 1.5m gantry style woodwork router. I have an old PII computer running at 222 hz. I have loaded ubuntu + emc, but can you tell me if I will be able to use it n a fairly basic router set up. Thanks for your recent answers Aaron -- Powered by Outblaze -- --- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now http://get.splunk.com/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users - This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now http://get.splunk.com/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] USB Wireless Network Steppers with encoders?
On Monday 06 August 2007, RogerN wrote: Would my EMC2 system work with USB wireless networking? I'm thinking of this because I could connect the USB wireless adapter to a USB extension and position it for better reception. I'm just not sure if it would work on my Ubuntu Linux EMC2 system. Another option would be a PCI card and an external antenna with cable. USB tends to create real time lag events, depending on whats plugged in. My 1600mhz system tolerates a USB mouse ok, but upchucks all over itself if I plug in a 64 megabyte usb key. As for networking, I have a 100baseT nic in mine, and ran a hunk of cat5 overhead across the back yard for a total distance from the hub here, to that box of about 140 feet, 3 years ago the weather hasn't killed it yet! That nic hasn't bothered emc2, currently at version 2.1.7 at all as I usually leave an IRC client running, and have been carving parts while typing at the guys on #emc. But adding in the lags caused by USB probably would not be healthy to emc's smoothness. Similarly, a wireless connection adds latencies too, so it wouldn't be a surprise to me to find that emc wouldn't work too smoothly while the radio is actually running without some means of disabling the radio while emc was running. You would have to turn it off, and unload the driver modules too I'd think. Also, after getting to play with hal configurations a bit, It seems like it wouldn't be too difficult to get steppers working with encoder feedback. If you would set up a pid loop = frequency generator and configure velocity feed forward to run the steppers at the commanded velocity, then pid gains could be set to take care of position deviations. This would be useful in detection and correction of lost steps for one. It would also give you the ability to connect encoders directly to lead screws or use linear encoders for actual position feedback. It seems like this would be a little more to set up than just plain open loop steppers but shouldn't be much more difficult than setting up a servo system. I don't think I've ever heard of a stepper based system that is capable of positioning from linear scales. That should take care of lost steps, lead screw errors, minor amounts of backlash, etc. Just a thought... Roger Neal - This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now http://get.splunk.com/ ___ 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) There's nothing wrong with teenagers that reasoning with them won't aggravate. - This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now http://get.splunk.com/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] USB Wireless Network Steppers with encoders?
While I can't comment on the wireless network other than it should work. I do have some comments on steppers and encoders. Unless you have some real high rent stepper drives capable of running your steppers at rediculess micro step counts encoder feedback is poimtless. First thing a proper stepper setup should NOT lose steps! Second if you add all the variables, tolerances, assembly, and missalignments in the machine you still probably can't justify using encoder feedback. Unless your machine is extremely accurate and near perfectly aligned, you would need drives and motors capable of very high microstep counts. Then your steppers could be run with encoder feedback and would act more like servos than steppers. IMO it would be much more cost effective and practical to just switch to actual servo drives. Less burden on the computer (EMC) and easier to implement. Glass scales are also expensive at high resolutions. To use Glass scales for position feedback requires a very tight positioning system with zero or near zero backlash. I'm sure that encoder feedback is possible to setup, I just don't see the need or benefit of it. Last words, a properly setup stepper system should NOT LOSE STEPS! And minor amounts of backlash can probably be ignored. I have .002 ~ .003 backlash. It's not really backlash but more of a windup due to motor coupling and the extra load of spring loaded anti backlash nuts. It doesn't present a problem as the machine repeats within .001 or better so the windup issue get's ignored and I have no problems with it. Just my 25 cents, (inflation) Dale RogerN wrote: Would my EMC2 system work with USB wireless networking? I'm thinking of this because I could connect the USB wireless adapter to a USB extension and position it for better reception. I'm just not sure if it would work on my Ubuntu Linux EMC2 system. Another option would be a PCI card and an external antenna with cable. Also, after getting to play with hal configurations a bit, It seems like it wouldn't be too difficult to get steppers working with encoder feedback. If you would set up a pid loop = frequency generator and configure velocity feed forward to run the steppers at the commanded velocity, then pid gains could be set to take care of position deviations. This would be useful in detection and correction of lost steps for one. It would also give you the ability to connect encoders directly to lead screws or use linear encoders for actual position feedback. It seems like this would be a little more to set up than just plain open loop steppers but shouldn't be much more difficult than setting up a servo system. I don't think I've ever heard of a stepper based system that is capable of positioning from linear scales. That should take care of lost steps, lead screw errors, minor amounts of backlash, etc. Just a thought... Roger Neal - This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now http://get.splunk.com/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users - This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now http://get.splunk.com/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Fw: [ emc-Bugs-1743942 ] MDI command in estop-resetruns in machine-on
My opinion. Possibly in e-stop reset, but NOT in e-stop itself. This is a safety thing, if e-stop is generated by hardware NO further operation should be possible until the operator acknowledges the e-stop. Steve Stallings -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Alex Joni Sent: Monday, August 06, 2007 3:50 AM To: emc-users@lists.sourceforge.net Subject: [Emc-users] Fw: [ emc-Bugs-1743942 ] MDI command in estop-resetruns in machine-on Hello, Pete brings up an interesting point. Is it allowed to issue some MDI commands while in e-stop reset or even e-stop mode? AXIS (the GUI) simply disables MDI while machine is not switched on. TkEMC relies on task to do the right thing, and enables MDI and allows users to send MDI commands, and task then discards the ones that are not allowed. What do you (CNC users ;) think should be the reasonable thing to do while the machine is not switched on? I can see valid reasons to do both approaches: some M-commands might be usefull while in E-stop .. to make some clampings move, activate things, etc. Otoh one might argue that while e-stop nothing is allowed to move/change. Awaiting your input. Regards, Alex - Original Message - From: SourceForge.net [EMAIL PROTECTED] Subject: [ emc-Bugs-1743942 ] MDI command in estop-reset runs in machine-on Bugs item #1743942, was opened at 2007-06-26 18:25 https://sourceforge.net/tracker/?func=detailatid=106744aid=1743942group_i d=6744 If an MDI command is issued in the estop-reset state, it is executed when the machine-on state is entered. I don't think entering the machine-on state should cause any motion or other type of command to execute. Any MDI commands issued in the estop-reset state should be ignored. -- Comment By: Pete Vavaroutsos (petev) Date: 2007-08-06 00:11 No, the behavior is different with the current CVS/trunk build. An error is given that says the machine must be enabled in coord mode when an MDI linear move command is issued in the e-stop reset state. However, commands like M3 are exectured immediately in MDI mode when in the e-stop reset state. Try the following: 1) Start a sim session using tkemc. 2) Get to machine on and home all axis. 3) Switch to MDI mode. 4) Change to machine off state. 5) Issue M3 in the MDI entry box. - This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now http://get.splunk.com/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users - This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now http://get.splunk.com/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] USB Wireless Network Steppers with encoders?
On Mon, 6 Aug 2007, Dale wrote: Date: Mon, 06 Aug 2007 08:40:26 -0400 From: Dale [EMAIL PROTECTED] 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] USB Wireless Network Steppers with encoders? While I can't comment on the wireless network other than it should work. I do have some comments on steppers and encoders. Unless you have some real high rent stepper drives capable of running your steppers at rediculess micro step counts encoder feedback is poimtless. First thing a proper stepper setup should NOT lose steps! Second if you add all the variables, tolerances, assembly, and missalignments in the machine you still probably can't justify using encoder feedback. Unless your machine is extremely accurate and near perfectly aligned, you would need drives and motors capable of very high microstep counts. Then your steppers could be run with encoder feedback and would act more like servos than steppers. IMO it would be much more cost effective and practical to just switch to actual servo drives. Less burden on the computer (EMC) and easier to implement. Glass scales are also expensive at high resolutions. To use Glass scales for position feedback requires a very tight positioning system with zero or near zero backlash. I'm sure that encoder feedback is possible to setup, I just don't see the need or benefit of it. Last words, a properly setup stepper system should NOT LOSE STEPS! And minor amounts of backlash can probably be ignored. I have .002 ~ .003 backlash. It's not really backlash but more of a windup due to motor coupling and the extra load of spring loaded anti backlash nuts. It doesn't present a problem as the machine repeats within .001 or better so the windup issue get's ignored and I have no problems with it. Just my 25 cents, (inflation) Dale Actually we can (and have) done encoder-feedback stepper systems in SoftDMC pretty well, but its hardly worth the trouble because: 1. Even with a 1000 line (4000 count) line encoder, you only have 20 encoder counts for the full range of PID output - pretty lumpy 2. This also means encoder - stepper alignment is very fussy, making it hard to get symmetrical drive, 3. When you are all done you get a stepper that acts just like a brushless servo, except its a 50 pole 2 phase servo which means the drive frequencies are much higher than a normal (2 or 4 pole) 3 phase brushless motor. This is not a good thing... Peter Wallace - This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now http://get.splunk.com/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Fw: [ emc-Bugs-1743942 ] MDI command in estop-reset runs in machine-on
Alex Joni wrote: Hello, Pete brings up an interesting point. Is it allowed to issue some MDI commands while in e-stop reset or even e-stop mode? AXIS (the GUI) simply disables MDI while machine is not switched on. TkEMC relies on task to do the right thing, and enables MDI and allows users to send MDI commands, and task then discards the ones that are not allowed. What do you (CNC users ;) think should be the reasonable thing to do while the machine is not switched on? I can see valid reasons to do both approaches: some M-commands might be usefull while in E-stop .. to make some clampings move, activate things, etc. Otoh one might argue that while e-stop nothing is allowed to move/change. Awaiting your input. Regards, Alex If I were building the machine, ANYTHING that could possibly hurt someone would be disabled IN HARDWARE when the machine is in estop. Anything includes clamps - getting caught in a hydraulically or pneumatically actuated vise could ruin your day. Ultimately the machine builder needs to make these decisions. For example, you could have a machine where opening the guards disables all spindle and axis motion, but does NOT disable the vise, because the operator is opening the guards specifically to change the part, and he needs to actuate the vise. Another example is visible on the Mazak at the CNC workshop. There is a manual tool-unclamp button that allows you to reach in, grab the tool, push the button, and remove the tool, then insert another tool into the spindle, push again, and the machine grabs it. That clamp is released by the machine hydraulics, and when the machine is in estop, it won't unclamp - estop stops the hydraulic pump. So you can't be in estop when you do such a toolchange. However, you want to be darned sure the spindle isn't going to start spinning while you are holding the tool. Things like the above imply the existance of intermediate states between estopped and machine on, each state with its own set of rules and interlocks. Depending on the level of fail-safe required, ClassicLadder may or may not be suitable for such logic. Some logic probably requires good old-fashioned electromechanical relays. Since the logic is different for every machine, it would be unwise (and probably less reliable) to embed it in EMC itself. Regards, John Kasunich - This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now http://get.splunk.com/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] 2 phase
On Monday 06 August 2007, Roland Jollivet wrote: (second send,..) Hi list Concept query; Looking at stepper drives, the general format seems to be 4 phases out, or Dir+Step, obviously saving two I/O lines. So why isn't a two phase signal used?. A 'quadrature' output? - you still use two lines - less worry about pulse duration - transmission line speed requirement is slightly eased as the lines step alternately - it applies equally to stepper or DC servo drives - there is no(or less) problem of timing error on direction reversal since the signal changes are 'slow' at this point Maybe this is common, or what did I miss? Regards Roland Jollivet For steppers, its generally better to offload the actual stepping to the motor driver. Most motor drivers actually use a pwm sort of overall current control, switching at 20 to 75 kilohertz a second. This also, by fiddling with the currents within the driver, allows microstepping to be done, in increments as fine as 1/10th step for some drivers. My own does 1/8th step and its almost ghostlike to see the motor turning at about 1/2 of an rpm in steps so small you have to look close to see its not a constant, essentially silent motion. The best you can do with quadrature signals is full step, and to get any torque at speed, you'll dump 98% of the motor power in current limiting resistors, big ones that still need active cooling. 40 years ago maybe, today? Makes no sense at all. Let the driver take care of the grunt stuff. - This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now http://get.splunk.com/ ___ 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) One can search the brain with a microscope and not find the mind, and can search the stars with a telescope and not find God. -- J. Gustav White - This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now http://get.splunk.com/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
