[Emc-users] Z-Axis Drifting Problem
Dear All, We have installed Motenc-Lite on two milling machines. X and Y axis on both machines show good repeatability and show no errors after long run. Z-axis shifts conitinously by repeated motion of 100mm for 400 times, the error shifts the Z-axis approximmately 1.00mm into the job ie error is in minus direction. Z-axis Motor and encoder have been exchanged with other axis, but the error remain in the Z-axis. Regards Nasir. - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Z-Axis Drifting Problem
Hi Nasir Good to hear from you again. You started using EMC a long time ago. Six+ years ago at least. Does it do the same sort of sliding down when the moves are fast as opposed to slow? Is it possible that you have mechanical slip between the axis and the feedback. If this is a motor with an encoder mounted on the end of it, is there any possibility of movement between the motor and the leadscrew. I can't see how electrical interference would cause bad counting in one direction only but you might make certain your encoder cables are grounded at the drive end only. We found just a little bit of difference in the ground potential between axes on the Motinc card we used with the Mazak but I don't see how that would cause this either. Rayh On Sat, 2008-05-17 at 11:02 -0700, nasir ahmed wrote: Dear All, We have installed Motenc-Lite on two milling machines. X and Y axis on both machines show good repeatability and show no errors after long run. Z-axis shifts conitinously by repeated motion of 100mm for 400 times, the error shifts the Z-axis approximmately 1.00mm into the job ie error is in minus direction. Z-axis Motor and encoder have been exchanged with other axis, but the error remain in the Z-axis. Regards Nasir. - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Z-Axis Drifting Problem
On Sat, May 17, 2008 at 02:33:04PM -0500, Ray Henry wrote: I can't see how electrical interference would cause bad counting in one direction only but you might make certain your encoder cables are grounded at the drive end only. I agree this sounds a bit strange, but I've seen this on two occasions. Once the encoder sensor was physically dirty, and in the other case there was electrical noise due to (iirc) bad grounding. In both these cases, the position error was consistently biased in one particular direction. You're right to suggest not dismissing electrical interference in this case. Jeff - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Z-Axis Drifting Problem
Focusing on possible mechanical sources: A Z-axis not capable of lifting the spindle at max slew, but sized well enough to drive the spindle down, would behave in this manner. Glenn -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Jeff Epler Sent: Saturday, May 17, 2008 3:17 PM To: Enhanced Machine Controller (EMC) Subject: Re: [Emc-users] Z-Axis Drifting Problem On Sat, May 17, 2008 at 02:33:04PM -0500, Ray Henry wrote: I can't see how electrical interference would cause bad counting in one direction only but you might make certain your encoder cables are grounded at the drive end only. I agree this sounds a bit strange, but I've seen this on two occasions. Once the encoder sensor was physically dirty, and in the other case there was electrical noise due to (iirc) bad grounding. In both these cases, the position error was consistently biased in one particular direction. You're right to suggest not dismissing electrical interference in this case. Jeff - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
