Guest
Show Posts
1
General Mach Discussion / help with z axis creeping
« on: December 22, 2007, 05:35:43 PM »
Greeting to All,
I am having a problem locating the problem (and a fix) for my z axis. It gradually "gains" height as the job progress. It is most noticeable when doing complex carvings such as those in vcarve that require a lot of small z axis movements. By the end a job it may have "added" as much as an inch. I usually end up carving fresh air. The x and y axis seem to be working great even with a high demand of detail. I have made some successful engravings such as my name and other basics like circles, squares etc. Here is what I have and what I have done so far. Any other advice?
Equipment/Software:
Sosylva designed cnc router (the large one, all belt driven), A dedicated P4 3.2 ghz w/XP Pro, Registered Mach 3, Vcarve Pro 4.5, Xylotex 3 axis board, CNC4pc BOB. There were no "known" modifications to any design and all parameters were meticulously set according to ALL of the aforementioned documentation. This machine runs like a dream and has since day one. The 289 oz steppers run very smooth at available speeds or accel.
With all of the possibilities like missing steps, resonance, binding, noise, settings, etc......Here is what I have tried so far:
1. Lots of reading and re-reading of all manuals/instructions.
2. Lots of reading and re-reading of forums like this one.
3. Changing the active low/high setting for step and dir. (no change)
4. Tried various speeds and accelerations. My last one was 15, 1. (no change)
5. Rechecked the xylotex board for proper voltage ref - 3.35 (no change)
6. Reduce the likelyhood of noise by using shielded cable and not with any power cables. I do not have limit or home switches yet. (no change)
7. Adjusted the debounce intervals, now at 5,000. (no change)
8. Finally, I removed the belt and gears completely from the zaxis and made a reference mark on the back of the stepper and ran a "dry" run under no load. I have repeated this with x & y disabled as well as the spindle motor off. (NO CHANGE)
Any thoughts?
I am having a problem locating the problem (and a fix) for my z axis. It gradually "gains" height as the job progress. It is most noticeable when doing complex carvings such as those in vcarve that require a lot of small z axis movements. By the end a job it may have "added" as much as an inch. I usually end up carving fresh air. The x and y axis seem to be working great even with a high demand of detail. I have made some successful engravings such as my name and other basics like circles, squares etc. Here is what I have and what I have done so far. Any other advice?
Equipment/Software:
Sosylva designed cnc router (the large one, all belt driven), A dedicated P4 3.2 ghz w/XP Pro, Registered Mach 3, Vcarve Pro 4.5, Xylotex 3 axis board, CNC4pc BOB. There were no "known" modifications to any design and all parameters were meticulously set according to ALL of the aforementioned documentation. This machine runs like a dream and has since day one. The 289 oz steppers run very smooth at available speeds or accel.
With all of the possibilities like missing steps, resonance, binding, noise, settings, etc......Here is what I have tried so far:
1. Lots of reading and re-reading of all manuals/instructions.
2. Lots of reading and re-reading of forums like this one.
3. Changing the active low/high setting for step and dir. (no change)
4. Tried various speeds and accelerations. My last one was 15, 1. (no change)
5. Rechecked the xylotex board for proper voltage ref - 3.35 (no change)
6. Reduce the likelyhood of noise by using shielded cable and not with any power cables. I do not have limit or home switches yet. (no change)
7. Adjusted the debounce intervals, now at 5,000. (no change)
8. Finally, I removed the belt and gears completely from the zaxis and made a reference mark on the back of the stepper and ran a "dry" run under no load. I have repeated this with x & y disabled as well as the spindle motor off. (NO CHANGE)
Any thoughts?