Re: [Emc-users] Realistic spindle encoder count for parallel port?
Hi, First, I assume the 1024 PPR indicates that the resolution of the encoder is 1024 cycles per revolution as defined in http://www.motion-control-info.com/encoder_glossary.html Hence 1024 full AB cycles per revolution. When using a 1024 PPR encoder, there will be 1024 A and 1024 B pulses per revolution. Since the A/B signals are directly read by the PC (via the parallel port), we have to make sure that every of the 4 phases of each pulse is sampled at least once by the PC in the time of one pulse. When pulses change faster than the PC samples, the PC will not see the changes, or loose track of the phase relation between the signals, and miss pulses. To compensate for possible fluctuations and inaccuracy of the phase and symmetry of the A/B pulses, we have to sample more often, e.g. 8 times per pulse-cycle (my guess). When running at 3500 rpm, there are (3500/60) * 1024 = 59733 pulses per second. When we want to sample 8 times per such pulse, we have to sample at least at 59733 * 8 = 477867 or about 480 000 times per second. That is once every 2.1 microseconds. Since your BASE_PERIOD = 62500 nanoseconds (62.5 microseconds) the sampling is about 30 times too low to be safe. When you keep the BASE_PERIOD = 62500 unchanged, and if you want to sample 8 times per pulse, the maximum number of pulses per revolution is: 1 / ((3500/60) * 8 * BASE_PERIOD) = 1 / ((3500/60) * 8 * (BASE_PERIOD / 10)) = 34 Hence, i think that your encoder should have no more than 34 PPR when keeping the rest unchanged and when using the safety factor of 8 pulse-reads per pulse (which still gives not too much safety). So, i am surprised that you can go up to about 600rpm without loosing pulses. Can anyone check this, please? Luc Steve Blackmore wrote: > Hi Guys, what's a realistic number of PPR for a lathe spindle encoder > via a parallel port in EMC. Spindle is capable of 3500 rpm. > > My home made encoder had 90, but I've altered the drive system and > fitted a 1024 PPR encoder with index. Output is via differential line > drivers. > > I've changed the scale factor but it starts loosing pulses at 600 rpm or > so?? > > Here's what's in my ini file > > [EMCMOT] > EMCMOT = motmod > COMM_TIMEOUT = 1.0 > COMM_WAIT = 0.010 > BASE_PERIOD = 62500 > SERVO_PERIOD = 100 > > Hal file reads > > setp encoder.0.position-scale 360.00 > net spindle-position encoder.0.position => motion.spindle-revs > net spindle-velocity encoder.0.velocity => motion.spindle-speed-in > net spindle-index-enable encoder.0.index-enable <=> > motion.spindle-index-enable > net spindle-phase-a encoder.0.phase-A > net spindle-phase-b encoder.0.phase-B > net spindle-index encoder.0.phase-Z > > Steve Blackmore -- Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Code help
Hi Rich, Rich Amaral wrote: > Hi guys, > > I'm looking through the code and can't seem to find the following files: > > rcs.hh > rcs_print.hh > timer.hh > > I believe I have the entire tree. Any help? They seem to be in the source tree here. .../emc2-dev/include/rcs.hh .../emc2-dev/include/rcs_print.hh .../emc2-from-git/emc2-dev/include/timer.hh Are you using the source tree from git? Luc -- Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] new to group
Chris, > I'll try that. The thing that confuses me is that the parts are coming out > right except for on one end of the part. Everything else seems to come out > just fine. It's hard to explain and might be a good idea for me to take some > pictures of the parts and post them on the web so others can see what it is > that I'm doing a bad job of explaining. Could it be that there is more friction at one end of the axis? If you return to the X0 Y0 Z0 coordinates after the work, is the machine coming to the original zero position, or is there an offset? Luc -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] new to group
Hi Chris, Chris Reynolds wrote: > I'm new to the group and I could use some help with a problem that I'm > having. I just built a new cnc machine and I keep running into a problem that > I can't figure out. I've been doing some test cuts, > problem is they always come up short on one end. I thought it was a > backlash problem so I put the dial indicator on the machine and ran it to an > inch. It came up like .040" short. So I > tried adding a backlash command to the ini file and that didn't fix it, > so it wasn't a backlash problem. Then I tried messing with the steps > and finally got it to come out right. Run it to an inch, dead on 0, run it > back to 0 and end up dead on 0 again. So then I run the > program again and the whole thing is now to long. It always seems to > come up short on one end. Checking the math the steps are right, I have a 20 > tooth pulley on the motor and a 40 tooth pulley on the leadscrew, running in > full step mode, so that comes out to 1600 steps per inch, which is what I > have in the program. It's almost like it's a compounded problem, like it's > off a small amount but then when you cut through the whole part it adds up. > But the weird thing is that it's off on one end. The part I'm cutting > resembels a comb, where you have slots cut into the part every so often, > there's a wider section at each end, on the far end it's right, on the 0,0 > end of the part that wider section is to short. I think that you are loosing steps. It may be that the MAX_VELOCITY or MAX_ACCELERATION settings for the axis [AXIS_0] ... [AXIS_2] in your .ini file are too large. You could test with very low values to check if that is the problem. Luc -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] X axis Homing in wrong direction
Hi Leav, > Hi Everyone! > First post here so I hope I don't mess this us up! > > First I've got to say that I'm REALLY impressed with EMC2, it's much much > better and user friendly than any other CNC program I tried (Mach3 and > TurboCNC). > > My problem is that I'm getting the X axis on my machine homing in the wrong > direction (Y and Z work fine). You can configure in what direction the homing sequence starts. It is all explained here: http://linuxcnc.org/docs/2.2/html/config_ini_homing.html If it is not clear, or if it is not working as explained in that page, call again for details. Luc -- Enter the BlackBerry Developer Challenge This is your chance to win up to $100,000 in prizes! For a limited time, vendors submitting new applications to BlackBerry App World(TM) will have the opportunity to enter the BlackBerry Developer Challenge. See full prize details at: http://p.sf.net/sfu/Challenge ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] more on using gamepads to drive a mill
Hi, sani.broy...@free.fr wrote: > Bien vu :-) > > But this space was caused by cut/past of message. > > It wasn't in your initial message and link. > > The message is "access denied" rather that "not found". > > Do you have an htaccess file ? A reverse proxy ? > > If US list members manage to get your URL, it's a WAN issue, don't bother > with > it, there is nothing that can be done except pushing it on a regular server. I can access the files all right from here in Belgium, Europe. Luc -- Enter the BlackBerry Developer Challenge This is your chance to win up to $100,000 in prizes! For a limited time, vendors submitting new applications to BlackBerry App World(TM) will have the opportunity to enter the BlackBerry Developer Challenge. See full prize details at: http://p.sf.net/sfu/Challenge ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] How to boot from USB without CD-Rom
Hi > Does anybody how to prepare USB-drive for booting without CD-Rom? I did > some trials according to some tutorials, but it fails. BIOS detects the > USB but it hangs up without any error. If you Google for Linux "Boot from USB" you will find lots of detailed descriptions. http://www.google.com/search?q=Linux+%22Boot+from+USB%22&; Luc -- Enter the BlackBerry Developer Challenge This is your chance to win up to $100,000 in prizes! For a limited time, vendors submitting new applications to BlackBerry App World(TM) will have the opportunity to enter the BlackBerry Developer Challenge. See full prize details at: http://p.sf.net/sfu/Challenge ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Weird EMC2 tuning issue ( direction reverses intermittently)
Hi, Gene Heskett wrote: > On Tuesday 07 July 2009, Luc Claeys wrote: >>>> I don't see value that specifically affects the direction valid time, >>>> but I definitely could be missing something... >>> Someone will probably chime in here. >> See parameters stepgen.N.dirsetup and stepgen.N.dirhold >> in http://linuxcnc.org/docs/2.3/html/man/man9/stepgen.9.html >> >> You can set these for each axis in your .hal file. >> >> e.g.: >> >> setp stepgen.0.dirhold 39000 >> setp stepgen.0.dirsetup 35000 >> ... >> setp stepgen.1.dirhold 39000 >> setp stepgen.1.dirsetup 35000 >> ... >> setp stepgen.2.dirhold 39000 >> setp stepgen.2.dirsetup 35000 >> ... >> > Humm, and these units are I assume, in nanoseconds? Yes, these time parameters are all in nanoseconds, hence 35000 means 35 microseconds. (the values are just examples). I assume all values will be rounded up to the realtime BASE_PERIOD Luc -- Enter the BlackBerry Developer Challenge This is your chance to win up to $100,000 in prizes! For a limited time, vendors submitting new applications to BlackBerry App World(TM) will have the opportunity to enter the BlackBerry Developer Challenge. See full prize details at: http://p.sf.net/sfu/blackberry ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Weird EMC2 tuning issue ( direction reverses intermittently)
Hi, >> I don't see value that specifically affects the direction valid time, >> but I definitely could be missing something... > > Someone will probably chime in here. See parameters stepgen.N.dirsetup and stepgen.N.dirhold in http://linuxcnc.org/docs/2.3/html/man/man9/stepgen.9.html You can set these for each axis in your .hal file. e.g.: setp stepgen.0.dirhold 39000 setp stepgen.0.dirsetup 35000 ... setp stepgen.1.dirhold 39000 setp stepgen.1.dirsetup 35000 ... setp stepgen.2.dirhold 39000 setp stepgen.2.dirsetup 35000 ... Luc -- Enter the BlackBerry Developer Challenge This is your chance to win up to $100,000 in prizes! For a limited time, vendors submitting new applications to BlackBerry App World(TM) will have the opportunity to enter the BlackBerry Developer Challenge. See full prize details at: http://p.sf.net/sfu/blackberry ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Help with probing on a surface with rotational symmetry - Comment on Wiki documentation
Hi Alan, Remark that you can choose in which directory the probe file is created by specifying the full directory path. e.g. (PROBEOPEN /home/alan/probefile) Luc > Jeff Epler wrote: >> Works as documented here. (PROBEOPEN filename.txt) immediately created >> filename.txt in the same directory as my inifile. >> >> Jeff >> >> -- > My apologies Jeff, > when I looked the file was in the same directory as the ini. Sorry I > just assumed that the file would be created in the users home folder and > just didnt think to look in the emc folder. I will know in future, but > wiki didnt mention where that that file was created, that is left to the > assumption of the reader and I assumed wrong. > > Alan -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] power off at the end of program
Hi, Steve Stallings wrote: > There are motor drivers that have internal logic to > automatically reduce the drive current while idle. > These will weakly hold position and run much cooler > when at rest. They can resume full power instantly when > a step pulse arrives. Of course, this is a feature > that the driver either has or doesn't have, no > signal from EMC can produce this result if the > driver does not support it. right. I realized something like that in my driver (.comp module) by loading a counter every time the stepper is clocked. When the stepper is not clocked in a cycle, i decrement the counter, and when the counter becomes zero, i reduce the current of the electronics. When a new stepper-clock arrives, full power is re-enabled. It works very smooth. This requires of course that you have a (electronic) signal to reduce the current, and that the electronics can increase the current to full power in a fraction of the time of one step. When the current is about one third of the normal current, the stepper holds very well its steady position. Luc -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Show Hidden Files and Directories????
Hi Aram, The ~ files are like the .bak files under MS-Windows. It exists on all operating systems. > what about with removing all files that with ~ mark? To remove all files ending with ~ use the command: rm *~ Luc -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Error with new program.
Aram, > File generated with CAD/CAM system. > 0-4.5CAM11.nc extention is "nc" > Type:NC File. > When open file it looks like 0-4.5CAM11.nc-Notepad I assume from the extension that you have edited the file with Notepad under Windows. Then the problem is likely caused by a 'carriage-return / newline' at the end of the line (as Frank has suggested). > Maybe i need to change extention to .txt and than take to UBUNTY -EMC2? The file extension is of no importance here. > In EMC2 I open text editor and use copy past. > > How i can detect problem? To see the invisible characters in the file, use the commands suggested by Rob and myself in earlier replies. You can post the output of this command. You can get rid of the carriage return characters (cr = \r) with the command tr -d '\r' < bad-file.txt > good-file.txt In which 'bad-file.txt' is the bad file, and 'good-file.txt' is a corrected copy. Watch the ',' and '>' tokens in the command above. Luc -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Error with new program.
Hi, > i use text edditor. and file has extention .txt Tell us which editor you have used. Was it on a Linux system? > in file everything cleare and problem. i save file. when load into EMC2 > lines 6 and 7 joint to line 5. > >> It sounds like there isn't a proper line termination character at the end >> of >> the lines. I'm not sure what emc needs, probably a linefeed, and you >> probably have a carriage return. > what that mean? in file text looks ok. May be this can help as background information: http://en.wikipedia.org/wiki/Newline#Common_problems To see all the printable and non-printable characters in your file, you can use the command: od -a > An editor like "vi" should show this. >> If not post the file as an attachment so we can see it. Indeed, that would help. Luc -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
