[Wi...] Posted October 6 Share Posted October 6 I've got a Zeiss Micura with a VAST XT Gold head. I have a part that is a shaft with a runout tolerance in which the datum is on the opposite side, and therefore not able to measure from one side. The solution was to turn the part on its side and use a star probe. The issue is, the star probe varies like nothing I've ever seen. I'll run the same part 3 times, it is always .100mm+ runout, and then after drop to .005 - .030 for the subsequent runs. Star probe is using 1.5mm probes with roughly 30mm shaft length. Qualification is done at 45 degrees so 2 of the 4 probes on the flat plane can be qualified, then it is rotated, master probe is qualified at the new location, and the remaining two probes are measured. Link to comment Share on other sites More sharing options...
[DW...] Posted October 6 Share Posted October 6 Please sign in to view this username. What are you using for spatial orientation? CMMs are not the greatest for runout measurements.. Link to comment Share on other sites More sharing options...
[Wi...] Posted October 6 Author Share Posted October 6 Please sign in to view this quote. I attached an image that describes it a bit. Datum B is being used for the spatial orientation. It is the largest plane on the part Link to comment Share on other sites More sharing options...
[DW...] Posted October 6 Share Posted October 6 Please sign in to view this quote. Please sign in to view this username. Try this - Create a circle on A, and a circle opposite A. Recall both circles into a 3d line. Set the spatial to the correct axis of the 3d line. Any improvements? 1 Link to comment Share on other sites More sharing options...
[Ma...] Posted October 6 Share Posted October 6 There should be only cylinder A used as a datum. It's runout on cylinder, but only a circle - total runout would be with whole cylinder - i am not sure how Calypso interpret this. 1 Link to comment Share on other sites More sharing options...
[Ky...] Posted October 6 Share Posted October 6 Another question would be "what is the ratio of the diameter of A to the length that you can measure?". If the diameter isn't significantly smaller than the length you can measure, it will not work very well for a datum. Link to comment Share on other sites More sharing options...
[Ke...] Posted October 7 Share Posted October 7 Please sign in to view this quote. If you are not, already: loop your base alignment. Also, report the form for all of your runout features, so you can see any deviations that might be affecting your results (and if they change from run to run) Link to comment Share on other sites More sharing options...
[Jo...] Posted October 8 Share Posted October 8 Are you qualifying on an appropriately sized reference sphere? We get lower sigma when qualifying on 8mm ref balls on probes smaller than about 1.5mm Link to comment Share on other sites More sharing options...
Recommended Posts
Please sign in to comment
You will be able to leave a comment after signing in