[cncoperator]

Thank you for all of the great advice everyone! To answer a few questions i was moving the Z up and back down each time because i wasn't sure about dragging the tip of the depth gauge, i will repeat the tests with an Interapid dial i have. with the Z backlash at <.0005 i don't think it would be too far off to move it up and down (at least compared to the 0.006 i'm seeing).

You're introducing all kinds of possible issues when you move Z up and down. It's even possible you have a Z axis issue and not a table one. There is no problem with dragging the tip as long as it only drops down slightly or you carefully move it up with your finger when crossing a T-slot. The few grams of force the plunger is exerting or the tiny force on the plunger housing isn't an issue.

[EvolveES]

You're introducing all kinds of possible issues when you move Z up and down. It's even possible you have a Z axis issue and not a table one. There is no problem with dragging the tip as long as it only drops down slightly or you carefully move it up with your finger when crossing a T-slot. The few grams of force the plunger is exerting or the tiny force on the plunger housing isn't an issue.

That is good to know, i think i will try with the indicator and just lift it up over the T-slots, I hadn't really thought it could be a Z height issue because i have made a lot of small parts and hit the Z depth to +/-0.001 pretty routinely, but it does make sense now that a disconnect in the Z DRO and stepper could show the same error. I'm going to check it out again not moving the Z.

[LSM]

Z axis isn't good enough repeatability to be moving up and down with DRO to be indicating the table
even a tool change introduces some difference

[EvolveES]

Here is a quick video of the measurements we got. We will call Tormach on Monday and see what they say.

www.evolveeng.com/HostedMedia/MillMeasurment.mp4



Thanks again everyone for all of your helpful input.