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General Mach Discussion / Problem cutting arcs and circles
« on: February 21, 2011, 10:33:43 PM »
Wondering if anyone can give some advice. Finally got my old CaMaster machine running about a month ago. It needed some rewiring, adjusting, and new software. The problem is when cutting a circle or arc I get a jittery, or whatever you would like to call it, result. The circle is the right average diameter and from a distance it looks good but there is a fluctuation of +/- .040" along the edge. The error is not consistant, I cut an O ring grove inside of a circle just to make sure.
The first circle I cut was very jittery but then I realized the feed direction was CCW and the spindle rotated CW. The feed direction is now CW along with the spindle and the result is better but still not perfect. I am using the Galil plug-in with linear interpolation checked under move settings and have tried different vector time constants and buffer levels settings to no avail, actually not much difference at all. I have adjusted the motor tuning and kernel speed in Mach3 and tuned the servos (PacSci) with WSDK from Galil but as this is my first experience setting up a machine, I'm not sure everything is correct. The gantry motion (axis A slaved to axis X) and Y axis are pretty smooth but not perfect. The Drives (PacSci) are set to torque mode as recommended by Galil.
My first attempts cutting a circle were with G-code from Lazycam, then tried the circle wizard found in Mach with about the same results, maybe a little better. I'm just hoping this is not a mechanical issue but after all the tweaking I fear this may be the case.
I also have an intermittent problem while jogging, sometimes the X axis decouples from its A axis slave. A resest in Mach usually corrects it.
Any help will be greatly appreciated.
The first circle I cut was very jittery but then I realized the feed direction was CCW and the spindle rotated CW. The feed direction is now CW along with the spindle and the result is better but still not perfect. I am using the Galil plug-in with linear interpolation checked under move settings and have tried different vector time constants and buffer levels settings to no avail, actually not much difference at all. I have adjusted the motor tuning and kernel speed in Mach3 and tuned the servos (PacSci) with WSDK from Galil but as this is my first experience setting up a machine, I'm not sure everything is correct. The gantry motion (axis A slaved to axis X) and Y axis are pretty smooth but not perfect. The Drives (PacSci) are set to torque mode as recommended by Galil.
My first attempts cutting a circle were with G-code from Lazycam, then tried the circle wizard found in Mach with about the same results, maybe a little better. I'm just hoping this is not a mechanical issue but after all the tweaking I fear this may be the case.
I also have an intermittent problem while jogging, sometimes the X axis decouples from its A axis slave. A resest in Mach usually corrects it.
Any help will be greatly appreciated.