[EMAIL PROTECTED] wrote: > > --- [EMAIL PROTECTED] wrote: > > From: John Kasunich <[EMAIL PROTECTED]> > To: "Enhanced Machine Controller (EMC)" <emc-users@lists.sourceforge.net> > Subject: Re: [Emc-users] Newbie Help Needed - Losing Steps > Date: Sun, 06 Apr 2008 19:46:09 -0400 > > Andrew Ayre wrote: >> Hi, >> >> I have a gantry style machine with three axis. The X and Y axis have the >> same motor and the same nut and lead screw on each). I am testing the >> machine using manually entered commands into AXIS such as: >> >> G01 F80 X1 >> G01 F80 X0 >> >> When manipulating one axis at a time (no cutting, just moving around) I >> have found that I lose steps at different feed rates for each axis. >> >> X - lose steps at 148 ipm >> Y - lose steps at 81 ipm >> > > All those calculations are for theoretical limits to the step rate. But > the reason you are losing steps is much less theoretical. You are > probably running out of torque. When step motors go faster, the amount > of torque that they can produce drops. When the load needs more torque > than the motor can make, you lose steps. > > It does seem odd that the X can go faster than Y. X has to move more > weight (I assume that X is the gantry, and Y moves a much smaller weight > across the gantry). But something is making Y require more torque than > X, so Y loses steps first. > > Regards, > > John Kasunich > > It looks to me like Andy is using full step motion. Probably what is > happening is that he's hitting resonant frequencies that are a bit different > for each axis. The extra weight of X might even work to advantage to help it > cross that zero torque spot. > > Rayh >
Hi Ray, yes I'm using full stepping. My next step was to switch to 1/4 or 1/8 microstepping. So could that actually help? I know that the speeds overall will be reduced of course. Andy -- Andy PGP Key ID: 0xDC1B5864 ------------------------------------------------------------------------- This SF.net email is sponsored by the 2008 JavaOne(SM) Conference Register now and save $200. Hurry, offer ends at 11:59 p.m., Monday, April 7! Use priority code J8TLD2. http://ad.doubleclick.net/clk;198757673;13503038;p?http://java.sun.com/javaone _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
