Measurement using probe different in X than in Y

[venom51]

I'm hoping someone here will point me in the right direction as I am stumped on a current problem.

The mill is pretty well dialed in and when setting motor stepping asking for an inch of movement results in an inch of movement. However I was setting up to mill a round piece of stock and when probing the X measurement is .050 larger than the actual measured dimension when measuring off the machine.

The Y measurement is a little small by a couple thousandth but close enough. Probe orientation does not seem to matter. Rotating the stock 90 degrees has no affect so I am stumped at why the measurement is constantly .050 larger.

I still end up entered on the part so I'm not sure where the error is coming from. I did the probe calibration so I don't think that's the issue. Probing at 30 first pass and 25 the second.

Any help would be greatly appreciated.

[venom51]

Nevermind...I found the error after thinking about it for a bit. Still have a about .012 out of round to work out but getting closer to making descent parts.

[DaveCVI]

Hi,
I was just reading your thread -
It's nice to know that you found what was causing the problem. When I read the first post, I didn't think of a cause that would give that symptoms no matter how you rotated the probe or the piece being measured.

Could you tell me what the cause was?

Dave

[venom51]

I had a gib that needed attention. That caused a systemic error in measurement. Re-adjusted..again. Re-measured steps per again and now the measurement is repeatable. It now measures within a few thou of the measurement taken off the machine. Still not entirely happy with the accuracy of the machine itself but that's not a software issue.

[DaveCVI]

Interesting, I wouldn't have thought that a sticky gibb would cause the same amount of error each time - I'll add that to my list of things to check if the topic pops up again.
Dave