On Monday 28 August 2017 16:25:06 Johann Beukes wrote: > Ok guys > Here's some more info on my problem. > I am very new to cnc so bare with me. > For example: Let say I want to cut a 10mm OD. The first part will be > spot on. The second will be 15 microns under and the third will be 15 > microns over and so it fluctuates with no definate repeatablility. > I have checked the x axis and my backlash is only 5 microns so the > mechanical side is ruled out. > > Here are some perameters from the .ini file > Dirsetup is 2500 > Dirhold is 2500 > Steplen 5000 > Stepspace 5000 > Stepscale -322 on a 2.5mm ballscrew. > Using a leadshine D808 drive.
I am having some mental headscratching with these figures. I looked that drive up, and its one of the newer servo-steppers with a 1000 line encoder in the motor for feedback. That statement leaves some ambiguity because a 1000 slot encoder would be, to a quadrature circuit, 4000 edges per revolution. So is it a 250 line, giving 1000 edges or a 1000 line, giving 4000 edges? > > I have been battling with this for 8 weeks with no success. > > Any help from you will be appreciated. > > Awaiting your responce. > > Best regards. > > Johann Beukes > > On 28 Aug 2017 14:47, "Gene Heskett" <ghesk...@shentel.net> wrote: > > On Monday 28 August 2017 07:52:14 jeremy youngs wrote: > > My 860 drives gave me a very hard time early on.only much sifting > > through the Chenglish did I realize the drive steps on the rise and > > fall. Requiring 1/2 the steps calculated. > > I have not found that to be the case here with a 'DM'860. Odd indeed. > The only comment I'd make is that the microstep current mapping is > somewhat less than ideal. It might be enlightening to put a scope > probe on the supply lines? Perhaps its ringing with the changes in > current draw? Just a SWAG mind you. > > > On Aug 27, 2017 11:12 PM, "Johann Beukes" <beukes1...@gmail.com> wrote: > > > Hi guys > > > I am struggeling alot with my lathe X axis. The machine does not > > > hold size at all. I am using The Leadshine ESM-22430 motor and the > > > DS808 drive. The Dirsetup is set at 2500, Dirhold 2500, Steplen > > > 5000, Stepspace 5000 and stepscale at -322. The ballscrew has a > > > 2.5mm pitch and the steps per rev are set at 800. Which since the motor is a 1.8 degree per full step unless its a 3 phase, is equ to a /4 setting in the driver, in which case it would be 320 steps per millimeter, not 322. The source of some of my head scratching since I am assuming the machine unit is a millimeter. Personally I'd like to see the microstepping at a higher resolution than the encoder, or the steps per rev at /8 or even /16 if that did not exceed the input bandwidth which at the G0 speed which the pdf said was 200 kilohertz. But your 5 on 5 off step times are restricting you to 100 kilohertz. Converted back to MAXVEL, thats 312.5 rpms at the motor, times the 2.5 of the screw=781.25mm/m, which if my math is correct, is marching along at a good speed for an x drive. Can you access the driver and see/adjust the deadband and backlash settings? Do you have a heater or AC source directly on the machine that could effect its temperature on the same time scale as making the part? Even coolant temps ought to be checked if coolant is used. Grasping at straws here for lack of info. Its even possible that you are the first to use one of these integrated drives, and that the rest of us can learn a bit about the care and feeding of this newer tech. There is, in the <wiki.linuxcnc.org> some data where one or two of the guys put an encoder on a stepper and incorporated that into the control loop, and there might be some clues in those case stories. Might be worth the time to read them if you have not yet. > > > Can anybody please give me some advice? > > > Thanks > > > ------------------------------------------------------------ > > > ------------------ > > > Check out the vibrant tech community on one of the world's most > > > engaging tech sites, Slashdot.org! http://sdm.link/slashdot > > > _______________________________________________ > > > Emc-users mailing list > > > Emc-users@lists.sourceforge.net > > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > > -------------------------------------------------------------------- > >-- -------- Check out the vibrant tech community on one of the > > world's most engaging tech sites, Slashdot.org! > > http://sdm.link/slashdot > > _______________________________________________ > > Emc-users mailing list > > Emc-users@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/emc-users > > Cheers, Gene Heskett > -- > "There are four boxes to be used in defense of liberty: > soap, ballot, jury, and ammo. Please use in that order." > -Ed Howdershelt (Author) > Genes Web page <http://geneslinuxbox.net:6309/gene> > > ------------------------------------------------------------ > ------------------ > Check out the vibrant tech community on one of the world's most > engaging tech sites, Slashdot.org! http://sdm.link/slashdot > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > ---------------------------------------------------------------------- >-------- Check out the vibrant tech community on one of the world's > most engaging tech sites, Slashdot.org! http://sdm.link/slashdot > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
