Stylus System won't calibrate

[[An...]]

Hi everyone!  

I.. am baffled.... help!

I have one star stylus that I cannot get to come in when I calibrate it to the reference sphere. All my other probes are running at S values of .0009 or lower.  The problem star probes vary from an S of .0050 to .0020.  So far... I have changed out one probe that was a tiny bit bent, I've put the star on a new plate, we've put the probes on a lathe to ensure they aren't bent, I've cleaned everything, I've looked at the balls under a microscope....  I feel like there must be something incredibly obvious that I'm overlooking.  Any help is appreciated!  🙂

[[Ri...]]

Please sign in to view this username.

Unless you are using some old Renishaw M2 styli, all of the M3/M5 styli are typically either carbide, carbon fiber, or ceramic - meaning they can't be bent without them breaking. 

Have you cleaned the reference sphere? Ensured that the reference sphere is tight to the reference sphere body? Ensured that the reference sphere body itself is locked down on the machine? What does your MasterProbe sigma values look like?

Can you show a picture of the buildup? What machine/sensor is this?

[[An...]]

Please sign in to view this username.

Hi Richard! 

I'd already cleaned the spheres and the probe tip, I'd remastered the sphere - just in case...  The reference sphere sigma is 0.0001

(On the bright side - after cleaning and remastering - it came in at 0.0001 vs the previous 0.0003.  

The sphere is tight down to the machine.

ALL my other systems come in beautifully.

It's a primso. 

I tried to balance the probes when I built it.

I even replaced this plate. It made zero difference....

I really appreciate your help!

 

[[Ri...]]

I think you have two things going on:

• Those are some long skinny styli shafts, so they are flexing.
• You have some long M3 extensions/styli. M3 stuff isn't robust enough for standard qualification on an active sensor. 

You can start by lowering your measuring force to 100, but you might have to go to 50. I would also reduce the probing dynamics to say 30%. 

Please note that even with this it is possible that you still don't achieve the results you are after. 

[[An...]]

Ugh - still bad.  Maybe I buy some stepped probes to get a little more rigidity...

[[Ri...]]

I have very similar star probe on an XTR sensor, I have had no problems with qualifying at all.

The only weak link is the Down position, is that a 1.5Ø stylus?

I would go with a stepped shaft for that.

Edited 6 hours ago