Z gets progressively deeper

[Stagecraft]

Running a job on our big Shopbot after it was moved, reassembled and set up in it's new location. Cutting multiple parts and it looks like the z is getting deeper and deeper to the point where the collet is about to touch the material. I should mention that we're running an "air" cut without a cutter in place just to test the machine.
It looks like the spindle isn't being lifted to it's proper safe Z every time it move to a new cut...any ideas?

[steve_g]

More than likely you have the multiplier value setting wrong...

SG

[Stagecraft]

Thanks Steve, that was my thought too. Just got off the phone with SB, changed the multiplier and still have the problem. It looks like the Z may not be pulling back up to full safe Z each time it moves to a new part...stumped???

[steve_g]

only other possibilities I can think of are the bit slipping in the collet or losing steps... Are your counter balance springs intact after the move?

I wonder if you have to re-start the software after setting the multiplier. Maybe it only reads it at startup...

SG

[jerry_stanek]

Have you checked the grub screws on the z stepper. Make sure there isn't one on top of another. some have 2 in the same hole and you think they are tight but they're not. Also check to see if the z is binding up where it is hard for the stepper to pull it back up and loose steps.

[paul_z]

Boyd,

I'd suggest disconnecting the cable to the Z motor and moving it up and down by hand. If it is binding, you'll feel it.

Also recommend cleaning the Z rack and pinion. Don't wait six years (like I did).

Paul Z

[Stagecraft]

Thanks all; turned out it was a multiplier issue after all. For whatever reason it was set to 4 in the controlling PC, Shopbot support suggested it be set to 5 which just lead to different problems.
As luck would have it, I had a decommissioned PC in storage that we used to control this table a few years ago; I hooked up a keyboard and monitor and checked the Unit Values on that computer and sure enough they were different. I reset the multiplier to 1 and now all is right with the world.:)
- Thanks again!

[steve_g]

Thanks for reporting back! Hopefully this will help someone searching in the future...

SG