I have a bigboy problem with my CMM, or well, rather a problem with the relationship between our 6 tips in our rack.
I've called hexagon support and they couldnt bring any help (also the good guy at support wasnt available today)
So now i want my friends (you guys) to help me! Cos i know some of you have the best knowledge n experience of this stuff!!
And... i cant wait for the other hexagon guy to help me, cos we have a big measuring error now..
So...I have two programs for checking our tips: a short & a long one.
Short one: I place a calibrated ring on our fixture plate. I measure & align to it with the master tip (with the rings top plane as Primary/Z-orgin and a circle with XY orgin).
Then it swaps to A0B0 for the next tip in our rack and measures the ring with a circle to evaluate Diameter, XY, Z(using a vector point on the face of ring) and also roundness to check for wear/dirt. I repeat this for all the other tips in the rack.
I get a big deviation in XY between the tips (0.05mm in X, 0.05mm in Y) and <0.01mm in Z. (I'll post the PDF report named "ring check")
The long check program uses the calibration sphere, where i use the same principle. Bolt the sphere to the fixture plate, Measure the sphere with mastertip A0B0 and align to it. Switch to another angle for the same tip and evaluate diameter/XYZ. Then swap to the next tip in the rack which measures the sphere and evaluates diameter/XYZ.
And I get the same big deviation in XY as in the ring check program. (Ive posted PDF report called "sphere check")
I have used these check programs for a long time and they've worked good so far.
So now....How do i get all the tips to show 0 in deviation (or at least <0.005mm per axis)?
Ive tried so far:
1. I ran our whole autocalibration program for all tips (which i also havent made any changes to) with good results, low STD, normal diameter deviation and the master XYZ is "perfect".
( ill post PDF report called "Autocalibration").
2. "Manually" calibrated the tips for the check program, i.e. I go into probe utlities for the first tip in our rack & calibrate A0B0 (master tip) saying "yes , sphere has moved". Then I go into the probe dialog for the 2nd tip in the rack and only calibrate A0B0 saying "no sphere hasnt moved". Ive done this for all tips in the check program with good results in the calibration results. But still bad results in the check program.
3. Ive reseted all tips to nominal and ran the autocalibration program again with good cal. results (But bad "check" results).
4. Ive inspected all tips for damage & cleaned them from dirt (also cleaned sphere/ring)
5. Played around with the calibration parameters for the tips, number of points & levels. And i acctually got sucess from this for the 2nd tip (Which you can see in the reports).
But i dont know why it worked, because it change anything for the other tips.
The only other thing i can think of that i havent tried is deleting the all probe files & build up new ones (If they became corrupt for some reason).
Anyone else has any ideas?
Just ask if u want more info, i can post code of the programs and show calibration settings etc...
Attached Files
