Hi Emory, Check out this page in the emc wiki.
http://wiki.linuxcnc.org/cgi-bin/emcinfo.pl?Stepper_Formulas I'm a servo person so I know almost nothing about steppers. Posting the make and model of the steppers and your drives will go a long ways toward someone providing the help you are looking for. HTH Dave On Dec 11, 2007, at 8:25 PM, Emory Smith wrote: > I'm having trouble with my DIY CNC engraver. > I've tried to include as much info as possible. > > Here's a picture to demonstrate the problem: > http://stratcat50.googlepages.com/YAXIS-BAD.jpg > The actual program is a 12 in ruler, this pict is just an example. > > It seems like the Y axis is dropping steps occasionally when moving > towards Y0. > I typically run 8-16 IPM cutting and 12-20 IPM rapids. > > I went through the machine today and did a complete clean & lube. > Tightened the cogbelt between Y motor and ballnut. > Made it the same as the X axis cogbelt which uses identical motor, > ballnut, cogbelt, etc. > Checked for binding, obstructions, etc. All OK. > I can do > F8 > G01 X18 Y5 > G01 X0 Y0 > and both axes return to 0. It only happens after many Y axis > operations. > > The shift does NOT always occur at the same place along the X axis > and is NOT a linear shift (ie; X=2 Y=0.01, X=4 Y=0.02, X=6 Y=0.03 > etc) > > The shift is NOT always the same amount. > > And... sometimes at the start of a program, the Y axis just growls > and doesn't > move. A little push and it's on it's way. > > All this using 5V 1A motors running off a PC power supply's +5 supply. > This afternoon, I connected the Y motor to the +12 supply through an 8 > Ohm/200Watt resistor. > It actually sounds better, but still has the shifting problem. > > It just started this recently. I didn't notice it when running Win/ > KCam. > Installed EMC from the live install CD on an IBM Net Vista, 256MB, > 667MHz Celeron. > kernel 2.6.15 magma, EMC/Axis 2.1.0 > > The latency test shows around 16000 after running 20 minutes. > I know Linux pretty well though have always run text mode in the past. > The GUI is new and foreign to me. (And this from a Mac user ;^) > > EMC appears to be running fine. > > Thanks for any suggestions, > > -- > Emory Smith > [EMAIL PROTECTED] > http://defoliants.googlepages.com > > ---------------------------------------------------------------------- > --- > SF.Net email is sponsored by: > Check out the new SourceForge.net Marketplace. > It's the best place to buy or sell services for > just about anything Open Source. > http://sourceforge.net/services/buy/index.php > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------------------------------------------------- SF.Net email is sponsored by: Check out the new SourceForge.net Marketplace. It's the best place to buy or sell services for just about anything Open Source. http://sourceforge.net/services/buy/index.php _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
