Z Axis Plunging too Deep into part < part zero, tool offsets, turns ratio >

[martyscncgarage]

Axis are all direct drive

Do you actually have three different pitch ball screws?
They aren't all the same?

[milling]

I did a test where I did an mid command to move the axis in various increments and each time I did this in plus and minus direction it mechanically move the a the amount I commanded in the mid
Could it be something with the wcs? I use wcs 54 over and over and don’t use other wcs - is that a problem? I would think not
Don’t even know why there are so many wcs? When I make a part I don’t mind re zeroing the part each time
Maybe when I rezero a part using the same wcs it doesn’t like it??
What do you think?

[milling]

X and y axis appear to have a 6 pitch and the z is 5 pitch
I guess I have to fix the y
I just used a ruler to count the threads but should be close enough to then fine tune
I know I have the wrong numbers in for y but that should not affect z

[martyscncgarage]

Did the machine come with the ball screws or did you buy and install them? Did you buy them from the same source?

I gave you two documents to help check and setup your axis. Give it a go.

[milling]

I started out a y equal to 6 but still ended up at 7.9 so I was pretty close at 8.04

Anyway my bigger problem is with z axis

I installed the ball screws my self and got all three from the same source
As I was saying earlier when I command a z move of 1 it moves 1
2 3 4 and so on so the z axis appears to be moving what I tell it to
Any comment on the wcs or how I am setting part 0

[milling]

Also was there something in the programs I sent that were wrong?
One program worked fine and the other did not
Is there something wrong in cam or intercom?

[cncsnw]

The CNC programs looked fine to me.

G43 height compensation was activated, with H numbers matching the tool numbers. Initial Z rapid-down moves go to +0.100. Subsequent Z moves feed to -0.100, or -0.250, or -0.375.

Next time the problem happens, or is about to happen (based on the DRO numbers), get that clear picture of the entire screen, and post it here, along with a fresh Report.

[milling]

The problem happens quite often and is very random. Sometimes the part runs as it should. Ill get a fresh report along with some photos.

Thanks

[martyscncgarage]

My hunch is you may need to back up first and check mechanicals and machine setup first. You also need to calibrate the axis.
Your report indicates you have 3 different pitch ballscrews which seems odd to me if they were all purchased from the same source.
Did you use angular contact bearings as thrust bearings on each axis?
Is this your first conversion by chance?

This is an old video but it still applies. It might help

[swissi]

The problem happens quite often and is very random. Sometimes the part runs as it should. Ill get a fresh report along with some photos.

How did you wire your drivers and motors. Is it possible that your drivers/motors are losing power or enable signal at some point of your operation? Turning off power or enable signal will turn off the holding torque of your motor and the mill head will creep down a little from gravity.

You need to re-home your machine every time you disable power to the driver/motor or remove the enable signal, otherwise your home position, especially on the Z-Axis, might not be accurate anymore.

-swissi