I am trying to run the famous VCarvePro Bullshead pub sign. My router starts off cutting the little squiggly design by the B, but by the time it gets to line 5000, the router tip is cutting air - it is .094 inches above the material.
Here's my setup Mach 3, Gecko 540, cncrouterparts.com motors 380oz-in, extension cables and 48v-7.3A power supply. Typical router (41.5" by 24" overall) running on skate bearings and pipe. Feed screws for x and y are 1/2-10 acme 5 start with Dumpster ABN. Feed screw for Z is 1/2-10 acme with delrin nut - no antibacklash...I figure the weight of the router motor provides some backlash compensation.
1. Slowed Z speed and accel way down 50 ipm and 10 i/s/s.
2. Lubed all feed screws.
3. Set all tool offsets to zero to make sure these were not sneaking in.
4. Tested with router on and off (above material).
5. Changed pulse width to 5 - but Mach3 kicks it back to 4.
6. Ran a trial program of about 50 z moves which ultimately came back to zero...and this worked like a charm.
7. Opened control cab to make sure gecko was not overheating - also checked by hand - I could hold my hand on there, so I am guessing it is 140 degrees F or less. Power supply is cooler than that.
8. I also chopped the Bullshead pub program in pieces - and it appears that all the z axis is out of position by line 5000.
9. I also used the Mach3 function to calibrate the X, Y and Z axes to match actual movement, and this looks good.
10. Marked couplings and feed screw on Z - could not detect any slip. Also cannot detect slip from coupling to motor shaft.
11. Disassembled Z axis and realigned tubes for the skate bearing carriages.
12. Remounted X, Y, and Z motors to make sure they is not hanging on anything.
I did have a slight problem in x and y axes not returning to correct zero, but the above seems to have fixed this problem.
Every so often when I try to jog the z axis, it does not respond. If I go into the motor tuning screen and change the smallest thing, it wakes up again. Is this normal?
So the only thing I have thought of now is to change out the Z axis feed screw to go to 1/2 - 5 start with a dumpster ABN...guessing it may be some kind of backlash problem.
Any other ideas. I would appreciate any help.