Part alignment using circle bushing on fixture

[[Sa...]]

Hello everyone,

I have a cad that is aligned to the circular bushings. created manual run first then auto run cnc using RPS free form method. However when trying to probe feature like circle true position looks good on the fixture, but by probing the deviation is too much is it because:

1) Cad is not aligned using circular bushings?

 

2) should i set base alignment to zero?

 

I am new to Zeiss Calypso. I have also attached my RPS Free form alignment. Just adding images of the circle bushings created result after auto mode.

 

Thank You

 

[[Ma...]]

You are missing a feature for main axis - in your case Z.

If you would have spheres instead of circles, then it would be fine, but circles won't give you correct Z reading in your case.

I would implement additional 3 touch points for Z as plane

[[Sa...]]

unfortunately i dont have tooling spheres its cylindrical bushings on the fixture. 

[[Ma...]]

Your problem is that you have not correctly defined primary plane ( not sure if it's your Z axis ) - look for A1/A2 on your circles.

You have to either measure 2x circle per bushing to gain cylinder like data or get your primary plane elsewhere.

If your part fits somewhere, then you can make start alignment by manualy obtaining that plane - then use RPS as base alignment.
Main part here: in start parameters select you wont to run base alignment, but in list of alignments select that start alignment. That should help you keep your primary plane.