[cobrakai]

Whenever I turn on my PCNC1100 Series 2, it asks to reset the ATC and Reference Z. I'm using Mach III. This introduces error in the Z of 1-2 thou due to the limit switch variability I assume. If I am running a project and it spans multiple days, the Z will vary slightly from day to day.

Is there a way to ignore the reference Z on startup? Resetting the ATC index is okay, but I'd rather not ref Z every time. If I don't let it reset the ATC/ref Z, it wont let me run a program until I do so.

Thank you!

[SCzEngrgGroup]

If you don't reference it, there is no guarantee you are still at the same position you were at when you turned the machine off. At a minimum, you can be off by as much as 3 full steps on the stepper motor, because the driver will always power up in the same (1 of 4) step state regardless of where it was at power-off. Also, the head may drop, due to weight. By far the best solution is to install better home sensors.

Regards,
Ray L.

[Jim Dawson]

When a job spans multiple days, I just leave my machine powered up. As @SCzEngrgGroup says, a more accurate home switch might be in order. I turned a really cheap snap action micro switch into a high precision home switch (+/- 0.0001) by increasing the ramp to vertical just before it snaps over. I couldn't hold +/- 0.005 before I did that.

[cobrakai]

Interesting. I like the ramp idea. I had no idea it would lose steps in between. I thought the brake on the Z-axis motor is supposed to lock it? I didn't think about the step state though!

Thanks guys. For now I will just use my touch tool each time.

[IMT]

I left my machine on for a week once, came back and finished the part. Unfortunately the machine had drifted more than .005 in Z and X. I don't know how or why. It's best to just reset your XYZ0's. Only takes a minute if you have a probe or a Hiemer.

[tmarks11]

Only takes a minute if you have a probe or a Hiemer.

Only takes a minute with a wiggler edge finder as well.