Re: [Emc-users] Is this list working?
Richard It's a SM1 with the Hurco amps. - Original Message - From: Richard Arthur rich...@candrarthur.demon.co.uk To: Enhanced Machine Controller (EMC) emc-users@lists.sourceforge.net Sent: Saturday, January 03, 2009 5:56 AM Subject: Re: [Emc-users] Is this list working? Donnie, ...snip With the help of Peter Wallace I found the info I was needing. I'm putting a 5i23 with a 7i33 and 7i37 in a hurco mill using the hurco amps. I'm new to Linux and EMC2. ...snip Out of curiosity, which model Hurco and amps? Regards, Richard -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] PCB routing on a CNC mill
Gene Heskett wrote: On Saturday 03 January 2009, Dean Hedin wrote: Take this one for example: http://www.hobby-lobby.com/brushless-gazaur.htm The R/C motors are rated with Kv. Which means rpms per volt with no load. The above motor is rated at 4100kv and can go up to 12volts. So that would be 49200 rpm. That link says up to 14.8 volts, which would be nearly 61k rpms. But surely a motor of that size cannot be rated for CCS service. 450 watts of input (30+ amps at 14.8 volts) would fry it in 2 or 3 minutes even if it was pumping its own cooling air. Or at least I'd think so. And this is the sort of info I'd need. Bearings aren't mentioned either, and even torrington needles have limits of around 150k rpms for their teeny cartridges needles. Well, the ultimate motors for this are Westwind air bearing spindles or Rockwell/Precise high speed spindles. The Westwinds are really designed for drilling, but can be used for light routing, too. You have to be real careful to keep the radial loads down to avoid crashing the air film in the bearing. These are about 2 diameter and 6 long. The motor rotor is about .7 diameter all the way, just a plain cylinder with a hat on the end for a thrust bearing. It will produce at least half a HP, and can go up to 80,000 RPM. It runs great on a VFD, although my VFD only goes to 400 Hz, so you get 24,000 RPM max. I also have a Rockwell/Precise spindle that will go to 45,000 RPM, and is rated at 3/4 Hp. It uses a 2-phase motor, so i don't have a proper system to run it yet. I did fire it up on a Gecko stepper drive, however, and it did run. I'm not sure it would develop rated power on that. The oldest Precise spindles have universal motors, and can be run on a Variac. Jon -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] EMC1 ?
On Sat, Jan 03, 2009 at 02:55:15PM +, paul_c wrote: ftp://ftp.isd.mel.nist.gov/pub/emc/emcsoft ftp://ftp.isd.mel.nist.gov/pub/emc/rcslib Thanks for these links, it seems getting the source there is the best strategy. I was surprised that emcplot3d is in there, though. Here is some of the old discussion about this: 22:32:18 paul_c Vreified the origins of emcplot3d and found it is subjuct to a non-commercial licence. http://www.linuxcnc.org/irc/irc.freenode.net:6667/emc/2004/2004-11-14.txt So even from that source, one would have to pick and choose carefully if making a commercial product. But you could avoid any possible trouble with the post-NIST people and/or work. -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
[Emc-users] info on emcsvr
As I reviewed the EMC2 source I came across 'emcsrv'. I could not find the source code for this server, at least not with this name or any detailed information about what it does. Does any one know? -Rich -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] web cam capture
Len Shelton wrote: Anyone know of a simple command line web cam capture program? I am running EMC2 on my pick-n-place machine. I want to be able to pick up a part, then move it over an uplooking webcam, capture an image, then proceed with placing the part. I want to be able to study these images to diagnose some centering issues we are having. I've used vgrabbj to capture images from the command line (for the CNC workshop webcam). Regards, John Kasunich -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
[Emc-users] EMC startup error
I'm have some problem the first the first time I start EMC after power on I get error and EMC will not start but start it again and it runs. Attached is a copy of the terminal screen. The second problem I'm turning the motors by hand and the z axis position reading goes the wrong way. I have switched the A B channel even tried move A to /A still get the same thing. I'm using the Mesa 5i23 along with the 7i33 and 7i37 card. Donnie don...@mill:~$ emc EMC2 - 2.2.8 Machine configuration directory is '/home/donnie/emc2/configs/hm2-servo' Machine configuration file is 'm5i23.ini' Starting EMC2... insmod: error inserting '/usr/realtime-2.6.24-16-rtai/modules/rtai_hal.ko': -1 File exists Realtime system did not load Shutting down and cleaning up EMC2... ERROR: Module rtai_math does not exist in /proc/modules Cleanup done EMC terminated with an error. You can find more information in the log files /home/donnie/emc_debug.txt and /home/donnie/emc_print.txt as well as in the output of the shell command 'dmesg' and in the terminal don...@mill:~$ emc EMC2 - 2.2.8 Machine configuration directory is '/home/donnie/emc2/configs/hm2-servo' Machine configuration file is 'm5i23.ini' Starting EMC2.. -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] PCB routing on a CNC mill
On Saturday 03 January 2009, Jon Elson wrote: Gene Heskett wrote: On Saturday 03 January 2009, Dean Hedin wrote: Take this one for example: http://www.hobby-lobby.com/brushless-gazaur.htm The R/C motors are rated with Kv. Which means rpms per volt with no load. The above motor is rated at 4100kv and can go up to 12volts. So that would be 49200 rpm. That link says up to 14.8 volts, which would be nearly 61k rpms. But surely a motor of that size cannot be rated for CCS service. 450 watts of input (30+ amps at 14.8 volts) would fry it in 2 or 3 minutes even if it was pumping its own cooling air. Or at least I'd think so. And this is the sort of info I'd need. Bearings aren't mentioned either, and even torrington needles have limits of around 150k rpms for their teeny cartridges needles. Well, the ultimate motors for this are Westwind air bearing spindles or Rockwell/Precise high speed spindles. The Westwinds are really designed for drilling, but can be used for light routing, too. You have to be real careful to keep the radial loads down to avoid crashing the air film in the bearing. Interesting. The length of the radial portion of the bearing must be fairly short then? Or the recommended air pressure to the bearing is too low. Back when we (tv stations) all had the 2 quadruplex vcr's, I often noted that turning a headwheel by hand with the air off was both difficult, and draggy like it was full of sandpaper. Bring up the compressor and it would turn freely even with 15 or 20 pounds of push on the rim of the 2 diameter wheel, and would sometimes turn slowly for minutes if it was given a push. Air pressure to those bearings was in the 40-55 psi range, and used maybe .5 scfm at that pressure. Guide posts also were air powered so the tape floated on an air film. They generally used more air in the venturi vacuum if the compressor wasn't double ended to make vacuum too. That could keep a 4 cylinder 2 horse oil-less Gast fairly busy. The vacuum was used in the shoe that held the tape in the curved shape as it was pulled past the spinning head, otherwise the head would have simply sawed the tape in two. These are about 2 diameter and 6 long. The motor rotor is about .7 diameter all the way, just a plain cylinder with a hat on the end for a thrust bearing. It will produce at least half a HP, and can go up to 80,000 RPM. It runs great on a VFD, although my VFD only goes to 400 Hz, so you get 24,000 RPM max. So it's not an air motor, just air bearings. How fast could it be brought to speed? Toward the end of the 2 vcr run, Ampex had a couple of machines that could give a locked picture in 400 milliseconds from a stopped wheel. Needless to say, the amps were about 100x overkill for cruising operation. The last 1200 I had at WDTV took about 2 secs to hit speed, and another 1.5 to 2 to achieve phase lock and output video that was airable. But it took a recalbration of all the servo stuff a couple of times a week to stay inside of 5 seconds, the standard pre-roll for those things. I also have a Rockwell/Precise spindle that will go to 45,000 RPM, and is rated at 3/4 Hp. It uses a 2-phase motor, so i don't have a proper system to run it yet. I did fire it up on a Gecko stepper drive, however, and it did run. I'm not sure it would develop rated power on that. The oldest Precise spindles have universal motors, and can be run on a Variac. Something us hobby types would gravitate to because of the cost. :) -- 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) If you think before you speak the other guy gets his joke in first. -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] OT: PDP11
Stephen Wille Padnos wrote: Lester Caine wrote: All this nostalgia set me thinking I had a silly text graphic based Dungeon and Dragon game on the VAX. It used to while away the lunch hour ;) anybody know if it's still available. I can't even remember the name now :( Either Zork, Hack, or Moria probably. Collosal Cave you are in a twisty little maze of passages :) - Steve TomP -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] OT: PDP11
tomp wrote: ... Collosal Cave you are in a twisty little maze of passages :) all alike or all different? TomP -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users Ken -- Kenneth Lerman Mark Kenny Products Company, LLC 55 Main Street Newtown, CT 06470 888-ISO-SEVO 203-426-7166 -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] EMC startup error
On Sat, Jan 03, 2009 at 05:41:49PM -0500, Donnie Timmons wrote: I'm have some problem the first the first time I start EMC after power on I get error and EMC will not start but start it again and it runs. Attached is a copy of the terminal screen. Do you use hal_manualtoolchange in your configuration file? At the end of a successful emc session, are any errors printed at shutdown? Another user on irc reported a similar problem, and it had to do with emc not waiting for a userspace component such as hal_manualtoolchange to exit before finishing cleanup. The second problem I'm turning the motors by hand and the z axis position reading goes the wrong way. I have switched the A B channel even tried move A to /A still get the same thing. You can also negate the encoder scale, which is usually the [AXIS_#]INPUT_SCALE value in the inifile but can be put directly in the hal file as well. However, I don't understand why the changes to the physical inputs you described wouldn't fix the problem. Jeff -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] OT: PDP11
On Saturday 03 January 2009, Kent A. Reed wrote: Gentle persons: I love these stories! I'm sorry, Gene, that you had such a bad experience. I can only protest that a PDP11/23 wasn't a *real* PDP11. It came out nearly a decade after the 11/20, had an LSI-based CPU instead of a boatload of M-series logic, used the Q-bus instead of the Unibus, and (the most telling point for me) didn't have a *real* front panel. All this is just rationalization, of course. The truth is, you had to deal with a lemon at a time when DEC was already beginning to reel from competition and market conditions. I (technically my advisor, since it was his grant money, but it was my lab partner and I who made the case and wrote the requisition) took possession of the third PDP11 sold out of DEC's Chicago office. As affordable as it was, it was so expensive compared to our research budget that we had to buy the CPU, ASR33 teletype, and power supply out of one grant, the 4(yes, 4!)-Kiloword core memory module out of another, and the high-speed paper tape reader/punch and relay rack out of a third. The system pictured on the home page http://hampage.hu/pdp-11/ might as well have have been my system. And is about 15x the size of that 11/23, which wasn't much bigger than an old AT style desktop. The model line was so new that my escutcheon plate said PDP11 and not PDP11/20 as it did on later machines. It was so early in the production cycle that I got documentation in the form of a set of E-sized drawings red-lined with the ECOs installed during manufacturing and a bunch of prepublication drafts of manuals. Of course, all those last-minute ECOs meant my backplane was chock full of colorful wire-wrapped patches. With the exception of inevitable core-memory issues (what minicomputer maker didn't have to run core-memory tests all the time?), the only real problems I ever had over the years were inevitably the result of forgetting to observe proper Unibus etiquette or screwing up my wire wrapping. When I complained about the lack of software documentation, the DEC Field Service Engineer surreptitiously passed me a number of source-code distributions which I cheerfully pored through at night while my experiments were running. It didn't take me long to discover that some of the early software was actually PDP8 software mangled so a PDP11 could interpret it, albeit slowly (not nothing did the PDP11 instruction set include the EMT, or emulate trap, instruction). I was the best of friends with the Chicago office after I showed them my version of BASIC-11 running 4 times faster than theirs because I had replaced the emulated instructions with native code. I didn't do it for them. Real men wrote only in assembler or directly in machine code. I had to make BASIC work well because my advisor was hopeless with anything else and he had some experiments of his own to run. Chuckle, and I was one of those Real Men who wrote the stuff that ran unmolested for years, in assembly, without in the first case, an assembler, I simply looked up the nemonic in the book and punched it into a hex monitor. I wrote one for an RCA 1802 based machine that way, and it was still in daily use at that tv station a decade after I had gone on down the road. I did use Basic09 on a color computer 2, at WDTV to write an EDISK for a Grass Valley 300-3-A/B production video switcher, replacing a package Grass wanted $20k for with one that was 4x faster and used english filenames. That ran for 14 years, only discontinued because we couldn't get the custom stuff to keep the grass running any longer. And about 15 years ago I wrote a file verification plus swiss army knife for the color computer that is still being distributed by Cloud-9. In assembly. But thats all for a much simpler platform than a linux box, so I haven't done anything too earthshaking for linux other than updateing a C syntax checker I had cobbled up 20 years ago on the coco. I found one kernel bug with it, but someone else had submitted a patch a few hours before me that fixed that. Shrug. These kids are maybe not as thorough, but a lot faster than this old fart nowadays. In defense of my taking up bandwidth on the EMC mailing list, the reason we bought this PDP11 was to control and monitor a very large and complicated experimental apparatus. Like a fly-by-wire aircraft, this system would have crashed and burned if it weren't for computer-based real*-time command, control, data acquisition, and processing. *I say real time, but keep in mind this was the early 1970s. I wrote my software and meticulously counted cycles before RSX11M or its country-cousin RT11 were available. Later, I got to spend some time debugging an RSX11M program as a favor to a medical researcher at the same university. Yikes. Drags up dusty memories I'd bet. I have a few too. :) Regards, Kent --
Re: [Emc-users] EMC startup error
Jeff I could not find any hal_manualtoolchange. I suppect that something is not get loaded at the right time. Being new to EMC and Linux I have no ideal what. I have used encoder in the past and to change direction just swap A B so this has me stumped. Attached are all the files in the setup folder. I hope they copy correctly as I don't have the machine computer on line at this time and have to copy through windows. Donnie - Original Message - From: Jeff Epler jep...@unpythonic.net To: Enhanced Machine Controller (EMC) emc-users@lists.sourceforge.net Sent: Saturday, January 03, 2009 6:59 PM Subject: Re: [Emc-users] EMC startup error On Sat, Jan 03, 2009 at 05:41:49PM -0500, Donnie Timmons wrote: I'm have some problem the first the first time I start EMC after power on I get error and EMC will not start but start it again and it runs. Attached is a copy of the terminal screen. Do you use hal_manualtoolchange in your configuration file? At the end of a successful emc session, are any errors printed at shutdown? Another user on irc reported a similar problem, and it had to do with emc not waiting for a userspace component such as hal_manualtoolchange to exit before finishing cleanup. The second problem I'm turning the motors by hand and the z axis position reading goes the wrong way. I have switched the A B channel even tried move A to /A still get the same thing. You can also negate the encoder scale, which is usually the [AXIS_#]INPUT_SCALE value in the inifile but can be put directly in the hal file as well. However, I don't understand why the changes to the physical inputs you described wouldn't fix the problem. Jeff -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users emc.nml Description: Binary data m5i23.hal Description: Binary data m5i23.hal~ Description: Binary data m5i23.ini Description: Binary data m5i23.ini~ Description: Binary data m5i23.tbl Description: Binary data m5i23.var Description: Binary data m5i23.var.bak Description: Binary data m7i43_th.hal~ Description: Binary data Readme Description: Binary data -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] OT: PDP11
Ok, I cant let this one go without a comment. I joined DEC as a sales engineer in the Ann Arbor Michigan office in Feb 1969. That was still PDP8 days, the 11 didnt come until 1970. We had a series of application systems we sold on PDP8's, and as I recall one of them was for generating NC code on paper tape. Ive got one box of DEC stuff packed away, and I think I still have something here about the NC system. Under my keyboard as I write this is a PDP15 logo panel, and somewhere around here there is still a trophy for the biggest PDP12 sale. I lasted until the end, bought by Compaq, then by HP, but I took the HP early retirement offer. I was in every state in the US, most of Europe, Japan, Australia doing sales support or training. It was a hell of a ride while it lasted. ron ginger -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] PCB routing on a CNC mill
Gentle persons: I know I should poll CNCZONE instead, but this is a much more friendly crowd and the rate of useful information exchange is much higher. I recently got a Tower Hobbies catalog to look for an RC gift to my son and/or his son. I stumbled across the brushless motors section and thought I was in nirvana. The current discussion about the use of these motors as spindle drives has brought me sharply back to reality. I am a hobbyist who's still wallowing in the world of the Dremel/Proxxon class of rotary tools while I get comfortable with the CNC aspects of machining but I'm always on the lookout for suitable spindles and motors to plan on moving up to. Do reliable, low-cost solutions exist? I assume that Gene's response to Jon about a Rockwell/Precise spindle---Something us hobby types would gravitate to because of the cost. :) ---was said in jest. Regards, Kent -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] EMC startup error
It must be a different problem than the one I was guessing at .. if you get any errors at shutdown, those would be useful to see. So would the last 20 lines or so that are shown when you type 'dmesg' at the commandline. Jeff -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] web cam capture
Len Shelton wrote: Anyone know of a simple command line web cam capture program? I am running EMC2 on my pick-n-place machine. I want to be able to pick up a part, then move it over an uplooking webcam, capture an image, then proceed with placing the part. I want to be able to study these images to diagnose some centering issues we are having. Google quickly turned up http://www.linux.com/base/ldp/howto/Webcam-HOWTO/framegrabbers.html where I see several techniques discussed. Regards, Kent -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] PCB routing on a CNC mill
Jon, that is overkill for PCB routing. I have a pcb routing spindle motor right here in front of me and it is not much more than a hobby dc motor. - Original Message - From: Jon Elson el...@pico-systems.com Well, the ultimate motors for this are Westwind air bearing spindles or Rockwell/Precise high speed spindles. The Westwinds are really designed for drilling, but can be used for light routing, too. You have to be real careful to keep the radial loads down to avoid crashing the air film in the bearing. These are about 2 diameter and 6 long. The motor rotor is about .7 diameter all the way, just a plain cylinder with a hat on the end for a thrust bearing. It will produce at least half a HP, and can go up to 80,000 RPM. It runs great on a VFD, although my VFD only goes to 400 Hz, so you get 24,000 RPM max. I also have a Rockwell/Precise spindle that will go to 45,000 RPM, and is rated at 3/4 Hp. It uses a 2-phase motor, so i don't have a proper system to run it yet. I did fire it up on a Gecko stepper drive, however, and it did run. I'm not sure it would develop rated power on that. The oldest Precise spindles have universal motors, and can be run on a Variac. Jon -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] OT: PDP11
Ken Kenneth Lerman wrote: tomp wrote: ... Collosal Cave you are in a twisty little maze of passages :) mine didnt say that it went you are in a twisty little maze of passages then you are in a maze of twisty little passages then you are in a twisty passage of little mazes then you were very lost :) heres the original PDP10 source for the original adventure http://www.rickadams.org/adventure/e_downloads.html all alike or all different? TomP tomp -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] EMC startup error
Peter I have TTL encoders so the /A and /B are not used or do I have connect them to ground? Is there any setting other than the jumps on the 7i33 to set for TTL Attached are the setup files Donnie - Original Message - From: Peter C. Wallace p...@mesanet.com To: Enhanced Machine Controller (EMC) emc-users@lists.sourceforge.net Sent: Saturday, January 03, 2009 9:20 PM Subject: Re: [Emc-users] EMC startup error On Sat, 3 Jan 2009, Donnie Timmons wrote: Date: Sat, 3 Jan 2009 17:41:49 -0500 From: Donnie Timmons dtimm...@etex.net Reply-To: Enhanced Machine Controller (EMC) emc-users@lists.sourceforge.net To: Emc-users@lists.sourceforge.net Subject: [Emc-users] EMC startup error I'm have some problem the first the first time I start EMC after power on I get error and EMC will not start but start it again and it runs. Attached is a copy of the terminal screen. The second problem I'm turning the motors by hand and the z axis position reading goes the wrong way. I have switched the A B channel even tried move A to /A still get the same thing. If swapping the A /A with the B /B pairs does not reverse the encoder direction, its possible you have some other problem like differential pairs mis-connected, say: ENC A 7I33 A ENC /A 7I33 B ENC B 7I33 /A ENC /B 7I33 /B Or maybe some general electrical problem... Its also possible that theres a problem with the 5I23 configuration (which one are you using?) but thats fairly unlikely. I can test it with a 7I33 on Monday. I'm using the Mesa 5i23 along with the 7i33 and 7i37 card. Donnie Peter Wallace Mesa Electronics -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users Readme Description: Binary data m5i23.hal Description: Binary data m5i23.ini Description: Binary data m5i23.tbl Description: Binary data m5i23.var Description: Binary data m5i23.var.bak Description: Binary data emc.nml Description: Binary data -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] OT: PDP11
Dave I agree Dave Engvall wrote: It is amazing how many DEC users, etc come crawling out of the woodwork. All of them with great stories about how things used to be. With all this architectural experience there ought to be some strongly held opinions on a processor chip that would do a good job on real-time applications such as emc and still be affordable. I really believe that someplace along the path Intel is going to make the Px unusable for real time. We as a group are going to need to be able to migrate to some other chip-set. Yes, I know I've been smoking the wrong stuff ... or maybe the right stuff. Ideas?? the processor and the hardware are as old as we are :} i think the separation of church and state is important... the RT stuff must be isolated from the user front end to the point of separate hardware, just to insure the thought is always enforced some of the GL problems that eliminate so many motherboards will be gone when there is no graphics on the rt 'computer' i think a non-computer is better, pmac fanuc mdsi dont use 'computer chips' they use big xilink and cypress devices or get ti chips foundered for them i understand thats not hobbyist in general or maybe it s better to say its a smaller set of hobbyists but there may be good reason to use vlsi custom, at least the big guys think so also the ui and io can be separate the ui 'AXIS' is a great tool, and it's pretty isolated now most io doesnt need rt features few io do ( laser on at start of line, pulse sync with distance traveled... ) the so called 'hi-speed' io only offered on TOL control systems. and as far as i can see, the code for the hi speed is NOT in with the 'plc level' stuff. yeh, i think the future of the hardware must be considered in any project that takes this much time effort to develop hell i'm just putting together off the shelf stuff and its taking months many vendors were not used in my project because they couldnt show me that something would be available for 5 years. The customer insist on it! and some things that could be available, well they werent available here yet ! doh! Dave tomp -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] OT: PDP11
Dave Engvall wrote: It is amazing how many DEC users, etc come crawling out of the woodwork. All of them with great stories about how things used to be. With all this architectural experience there ought to be some strongly held opinions on a processor chip that would do a good job on real-time applications such as emc and still be affordable. I really believe that someplace along the path Intel is going to make the Px unusable for real time. We as a group are going to need to be able to migrate to some other chip-set. Yes, I know I've been smoking the wrong stuff ... or maybe the right stuff. Ideas?? Dave oh one more thought change this topic to future hardware platform tomp -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] OT: PDP11
Dave Engvall wrote: It is amazing how many DEC users, etc come crawling out of the woodwork. All of them with great stories about how things used to be. With all this architectural experience there ought to be some strongly held opinions on a processor chip that would do a good job on real-time applications such as emc and still be affordable. I really believe that someplace along the path Intel is going to make the Px unusable for real time. We as a group are going to need to be able to migrate to some other chip-set. Yes, I know I've been smoking the wrong stuff ... or maybe the right stuff. Ideas?? Well ... I agree - mainstream CPUs are heading further from responsiveness and determinism and closer to throughput and streaming. Realtime interrupt latencies for audio and video (the applications most users interact with which actually need some level of realtime response) are in the several millisecond range, and that can be extended with buffering. Additionally, off-loading the work onto a specific processor (the sound chip or GPU) reduces the CPU load. So the path most hardware vendors take is to make special-purpos chips with large buffers, and don't worry about realtime. Then there's us. We need hard deadlines for interrupt service routines, reasonable determinism as to how long our functions will take to execute, and very fast turnaround time from our hardware helpers (like Mesa, USC, etc.). Even with sub-microsecond interrupt latency, USB would still be useless for many classes of machine, simply because it has 2ms (theoretical) minimum turnaround time for feedback/command data. As for determinism, it's nearly impossible to predict how long a function will take to execute on a modern processor. You can calculate min/max times (assuming you can eliminate paging/swap from the equation, which you can for RT code), and you have to do some statistical combination of the min/max for the various functions you need (in a HAL thread, for example). I believe there are CPU instructions that allow you to lock data in the CPU cache, which should improve both latency and determinism. I don't know how to figure out what parts of data should be held in cache, or what to do if something goes wrong (I don't know if we could tell that anything had been locked in cache in the event of a crash, for instance). To put it plainly, I agree - unless some CPU and/or chipset vendor takes the kind of RT we need seriously, things are going to get bad in the next 5-10 years (if not sooner). Of course, this ignores the role of software in the whole mess. Supposedly, non-RT code can't prevent RT code from running. I've had experiences which appear to support this assertion, and others that seem to contradict it. On the plus side: I've had a machine lock up badly enough that it wouldn't respond to pings, keyboard lights wouldn't toggle, etc. The HAL code kept running quite nicely though, in fact ending up with much more consistent timing with the kernel crashed than it had with the kernel alive (as verified by an external scope). On the minus side: I found on one machine that going from ext3 to ext2 eliminated a latency spike that occured about every 5 seconds. (Actually, I guess both examples are on the minus side regarding non-RT code affecting RT latency, since both cases showed an improvement in latency numbers once non-RT (but still kernel) code was stopped or disabled (or crashed)). I have had delusions about designing a PC-style motherboard with RT/latency as the priorities rather than benchmarks and video throughput, but that's a big (BIG) task. Points to ponder anyway. - Steve -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
[Emc-users] A wish - Closed Loop Steppers
It's unfortunate that there isn't a way to approximate closed loop control with steppers and encoders in EMC2. I have read that EMC2 can detect a following error using steppers with encoders and trigger a fault which is great but this doesn't really allow the use of steppers in larger or high performance machines. It would be great if you could run a stepper like a brushless servo. Steppers and drivers are cheap and easy to interface. Roger -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] OT: PDP11
Gene Heskett wrote: [snip] On the other hand you can do a lot with a embedded 32 bit processor in a FPGA (the ZPU for example uses about 20% of a 400K SP3, runs at ~ 100 MHz, is BSD licensed and has a GCC toolchain) Which again, sounds like a plus till you said 100mhz. That might do for servo driven machines but I'd guess it won't run steppers at usable speeds will it? Apparently you missed the point that this is a processor embedded in an FPGA, so presumably you'd have the hardware needed for fast step generation, PWM, encoder counting, etc. - Steve [snip] If I was awake, its too late now for me, I might carve up a message to lkml, and see if anyone has an idea of how much trouble it might be to pretend a 4 core phenom is a 3 core chip, and hand the 4th core to rtai, operating not in a sandbox cuz that would deny hdwe access, but I'd think something along those lines could be put together, and probably without major surgery to the core smp code linux now has. Linux and RTAI support isolated CPUsets. You can tell Linux to not schedule process on certain cores, and then tell RTAI to bind processes to those cores. EMC2 already does this by default when compiled on SMP machines, though you do need to supply the correct boot parameters to the kernel. In practice, I haven't seen a great improvement from simply going to a multi-core CPU. I haven't tested every machine out there though, so who knows. - Steve -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] OT: PDP11
Dave Engvall wrote: Anyone really remember how many interrupts an 11 really had. I'm thinking 256 but haven't found the book to confirm that. I think it was actually unlimited, up to filling the entire address space. Now, off the shelf boards didn't support that, and some of the early CPUs may not have, either. But, I'm fairly sure that on later machines you could actually use 1024 different interrupt vector addresses, which would take up 4096 bytes of memory. Many of the later boards such as comm multiplexers and Ethernet boards had writable interrupt vector addresses, and the system put them at the high end of the vector address space. (My memory may also be contaminated by VAX information.) Jon -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] PCB routing on a CNC mill
Gene Heskett wrote: Interesting. The length of the radial portion of the bearing must be fairly short then? The radial bearing sections are about 3/4 long, I think. These are combo hydrostatic/hydrodynamic bearings. I once had a hose blow off while drilling a hole, and waited until the drill was out of the hole to pause EMC and shut off the motor. It seemed to spin down pretty normally without the bearing air. Or the recommended air pressure to the bearing is too low. Back when we (tv stations) all had the 2 quadruplex vcr's, I often noted that turning a headwheel by hand with the air off was both difficult, and draggy like it was full of sandpaper. These are noticeably more draggy without air, but definitely not like sandpaper. Recommended pressure is 80 PSI. These are about 2 diameter and 6 long. The motor rotor is about .7 diameter all the way, just a plain cylinder with a hat on the end for a thrust bearing. It will produce at least half a HP, and can go up to 80,000 RPM. It runs great on a VFD, although my VFD only goes to 400 Hz, so you get 24,000 RPM max. So it's not an air motor, just air bearings. Yes, a 3-phase induction motor. How fast could it be brought to speed? It can be accelerated quite quickly. As my VFD was never intended to run a motor like this, I take it easy on the startup and slowdown, and the VFD becomes noticeably warm when I run it. It stays stone cold when rnning my 1 Hp Bridgeport. I think I have it set to accelerate to 24,000 RPM in 1.5 seconds. Jon -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] OT: PDP11
Ron Ginger wrote: Ok, I cant let this one go without a comment. I joined DEC as a sales engineer in the Ann Arbor Michigan office in Feb 1969. That was still PDP8 days, the 11 didnt come until 1970. We had a series of application systems we sold on PDP8's, and as I recall one of them was for generating NC code on paper tape. Ive got one box of DEC stuff packed away, and I think I still have something here about the NC system. Under my keyboard as I write this is a PDP15 logo panel, and somewhere around here there is still a trophy for the biggest PDP12 sale. I lasted until the end, bought by Compaq, then by HP, but I took the HP early retirement offer. I was in every state in the US, most of Europe, Japan, Australia doing sales support or training. It was a hell of a ride while it lasted. Oh boy! I remember the PDP-12 fondly! I also worked a bunch on the LINC, the computer with the OTHER instruction set that was in the LINC-8 and PDP-12. I also used a PDP-5 (discrete transistor predecessor to the PDP-8, same instruction set). It is nice to know that ALL of these machines are in the Computer History Museum in Palo Alto. If you ever get out there, you REALLY have to take a trip down memory lane! Jon -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] A wish - Closed Loop Steppers
Roger wrote: Stephen Wille Padnos spad...@... writes: This is a function of the motor driver, not the control software. Steve, Your absolutely correct but I could imagine how software could be used to emulate closed loop control with a step direction drive. In the case of a lost step software could lower the axis speed/acceleration and add or subtract the step value from the machines current position so that the trajectory planner could take the lost step into account. If a step motor loses a step due to excessive loading, then it's likely to miss many steps. The one motor will be stalled while the software ramps the speed down on the other joints, so the part is already likelly to be ruined. At some random time, the stalled motor will start moving again, but it's trailing the position it should be in. The motion controller can't speed the motor up to catch up to where it should be (ask it for a little more, like you'd do with a servo), since it's already at or beyond its limits or it wouldn't have stalled in the first place. Not perfect but maybe good enough. Could be. This has been discussed at length, both here and by various Geckodrive folks. EMC2 has the ability to get feedback, and it has the ability to apply feed rate overrides in realtime. If you can figure out an algorithm to marry the two to get pseudo-servo steppers then I'd be happy to review your code - patches gratefully accepted ;) - Steve -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] PCB routing on a CNC mill
Dean Hedin wrote: Jon, that is overkill for PCB routing. I have a pcb routing spindle motor right here in front of me and it is not much more than a hobby dc motor. Well, it depends on what you are going to be doing. I have drilled .018 holes (.457 mm) with the Westwind, and I'm sure it can do smaller. I have drilled a whole board without breaking a single bit. I have it rigged up so I can put it on my Bridgeport in a couple minutes. See http://pico-systems.com/wwspndl.html for a few pics. I actually got the motor for free, I got a bunch of stuff off an Excellon tape-NC PCB drilling machine. This thing had an air bearing X-Y slider table on a 5' x 5' x 8 thick granite surface plate that was supposed to weigh 17000 Lbs! I got the X-Y drives with insanely accurate ballscrews, the two spindle motors and a bunch of other stuff for $300 many years ago. The X-Y drives and ballscrews are on my Bridgeport. Jon -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] OT: PDP11
Dave Engvall wrote: It is amazing how many DEC users, etc come crawling out of the woodwork. All of them with great stories about how things used to be. With all this architectural experience there ought to be some strongly held opinions on a processor chip that would do a good job on real-time applications such as emc and still be affordable. I really believe that someplace along the path Intel is going to make the Px unusable for real time. We as a group are going to need to be able to migrate to some other chip-set. Yes, I know I've been smoking the wrong stuff ... or maybe the right stuff. Hmmm, some of the Alpha boxes might have been decent, but then they turned them into PCs, even with the dreaded blue screen! I think there is some potential for the Arm9 series. Jon -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] PCB routing on a CNC mill
Gene Heskett wrote: Something that wasn't actually because I was thinking of braced up dremels or Proxxon's. OTOH, I imagine the Rockwell/Precise offering is also outragiously priced, way out of my league, so that most certainly should have been taken as a jest. But at the time, I was serious without taking time to consider the whole picture. :) I got mine for about $150 on eBay. I will eventually get around to making a VFD for it. Jon -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] A wish - Closed Loop Steppers
On Sun, 4 Jan 2009, Roger wrote: Date: Sun, 4 Jan 2009 06:17:04 + (UTC) From: Roger vrsculp...@hotmail.com Reply-To: Enhanced Machine Controller (EMC) emc-users@lists.sourceforge.net To: emc-users@lists.sourceforge.net Subject: [Emc-users] A wish - Closed Loop Steppers It's unfortunate that there isn't a way to approximate closed loop control with steppers and encoders in EMC2. I have read that EMC2 can detect a following error using steppers with encoders and trigger a fault which is great but this doesn't really allow the use of steppers in larger or high performance machines. It would be great if you could run a stepper like a brushless servo. Steppers and drivers are cheap and easy to interface. We have some experience doing this but IMHO it is of somewhat questionable value. To actually work as a servo requires a high resolution encoder to get reasonable _electrical_ angular resolution. We had direct control of the two phase currents (vector drive). Controlling the feedback with steps would be harder (and inefficient as torque is applied when not needed) Also step motors make poor brushless servos, mainly because they have too many poles (50 versus 2 to 8 for most brushless motors), resulting in too-high drive frequencies and consequent loss of torque at high speeds. For EMC to do this it would have to run a servo loop at the ustep rate, adjusting the rate as needed. It would also help if the number of micro steps were greater than 10. Not impossible but not a trivial task, requiring very fast I/O. Roger -- ___ 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. -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] OT: PDP11
On Sat, 2009-01-03 at 21:38 -0800, Rafael Skodlar wrote: No modern PC with water cooling, tons of LEDs, or shiny fans look as good as PDP-8 or PDP-11/44 front panels. You could tell what system was doing just by looking at LEDs. I know what you mean, I started my computer career in 1981 working on these and I've always found PCs rather bland in comparison: http://users.monash.edu.au/~ralphk/burroughs.html Scroll down until you get to The awesome backplane. Source of many intermittent faults and surely the last word in heroic complexity. I learned a lot working on these... Thanks, Matt -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] A wish - Closed Loop Steppers
On Sat, 3 Jan 2009, Kirk Wallace wrote: SNIP__ With only step and direction signals on stepper driver inputs, EMC has no way of modifying the stepper driver behavior. The driver would need something like a step bias or correction input, which EMC could probably be configured to work with. If you want to compensate for missed steps, EMC can send more steps as needed, but you will most likely end up with just more missed steps until you get a following error, just like when a servo stalls. Those that have encoders on there stepper machines, may correct me on this. Well it may be possible to avoid missing steps because once aligned, the encoder count mod (mumble mumble) can tell EMC the mechanical rotor phase, and the step count mod (numble numble) tells EMC the stator electrical phase so a kind of D-term only vector drive is created. Whether its practical or stable is an _interesting_ question... SNIP___ Peter Wallace Mesa Electronics (\__/) (='.'=) This is Bunny. Copy and paste bunny into your ()_() signature to help him gain world domination. -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
