Looking for opinions

See my post below for a more detailed response..

I origin to the sphere using my master probe, then I check all of my tips X,Y,Z, RN, and DIAM at A0B0. Out of those tips, only one of those tips I also check A90B0 and A90B90, which I normally choose a stylus at least 100mm long. If I choose a longer stylus build, I get more error than I'd like in my verification, and since I'm already holding my tip correlation to a tight tolerance, I stick with ~100mm for my 90s.
I give the X, Y, and Z location tolerances +/-.005mm, diameter I give +/-.003mm, and roundness .003mm. I do this for a few reasons..
There isn't really a tip to tip correlation spec on these machines and I want to ensure I can check tight tolerance features using multiple probes if necessary. Extremely tight tolerances, I try and limit tip exchanges or even wrist rotations, but it's rare I need to worry about it.
I've had very good success being able to hold .005mm tip correlation and only rarely exceed .003mm. Although, it's always a judgment call for me when to put the machine down for a calibration. If one tip has a .0055mm deviation in one axis, I will usually accept it as-is and put the machine in a calibration during off hours so the floor is less affected. If I do not like the results of my verification, I put the machine in a full calibration since I have no confidence in the rest of the angles I am not checking.
The diameter measurement is really checking the accuracy of my tips and should never have a deviation even close to .003mm otherwise something else is going on.
Roundness I added so I can detect debris, tip damage, or sphere damage. This ensures we properly clean and inspect our probes once per shift so we can give the machinists numbers they can trust.
The two 90 deg checks I added just so I could see something other than A0B0 to give me more confidence that the rest of the angles should be OK. This also tells me if a crash happened that could have tweaked the head a little that I may not have seen otherwise. There have been too many times the 90s would fail with a high degree but the 0 angles were in my internal specs after minor crashes.
This verification program is really just a quick 20min gut check to ensure the tip calibration is still valid. I didn't feel more was needed otherwise I would go down a rabbit hole.
I perform a full calibration every Friday at the end of the shift so the machine is primo when we get into work on Monday. I have seen great success with little to no weekday downtime doing this unless someone decides to crash the machine. No way around that. The turtle button can be hard for some people to see..
The verification program is built into the calibration program so it runs automatically after the tip cal so we don't have to worry about running 2 programs.

I also have a ball bar I plan on using as a monthly check but I haven't implemented it yet. Time is hard to come by and machines need to keep running. I plan on implementing this within a month or so. I'm less worried about this since we have yearly Hexagon calibrations.

Also, I have 14 tips in my rack. In order to ensure temperature doesn't effect my calibrations (they take roughly 8 hours to calibrate and growing), I have my program re-pick up the master and find the sphere after every 2 tips using DCC-DCC and saying Yes to if the sphere moved. I would never pass my verification program if I didn't do this.

Sounds like you have oodles of time in your shop! We run three shifts and barely get 5 minutes in between parts to calibrate. It's one of those new, highly advanced shops with never enough time to do things right, but always enough time to do them over.

We don't have oodles of time. That's why I do what I do. We have very large and very small parts, so keeping the sphere on the stage is not an option. If I required people to calibrate the tip angles before each program ran, there would be mutiny. I rarely have to calibrate anything during critical hours which makes it all worth it. Only when crashes happen. We have parts with .060in tolerance and some with .0005in or less tolerance for medical and aerospace, so just letting a crash slide isn't an option for me. We only run 2 shifts, which, is better than 3 so I can find some time throughout the day to perform my calibrations, but even during critical hours I am willing to shut a machine down if my tip correlation isn't up to snuff.
Although, if I only had to deal with .020in tolerances, I wouldn't be near as critical. With those tolerances, I wouldn't shut the machine down unless tip correlation exceeded .002in. (10%)

Sounds like you have oodles of time in your shop! We run three shifts and barely get 5 minutes in between parts to calibrate. It's one of those new, highly advanced shops with never enough time to do things right, but always enough time to do them over.

How many CMM machines do you have?

I hadn't thought to check just one tip with an additional A90 angle. That doesn't add much time and still does a lot to check for a rotational shift in the probe head. Thanks for the idea.

Good stuff... Thx for taking the time to write this up!

Three. The bigger problem though is lack of experience in our shop. I program. The others just run parts, and there's about a total of 1 year experience between them.

"so just letting a crash slide isn't an option for me."

It isn't an option for me either. I don't consider a tip falling off as a "crash" though. An inconvenience for sure, but one I can live with under the right circumstances, namely, parts with large tolerances. We have the same range in tolerances you do. If a tip drops off from a rotation, the tighter tolerance parts will get a recalibration without question.

Maybe you missed my earlier question. Would you share your internal verification program?

If in doubt, re-qualify.

Realistically, however, if you have a 20x5mm, no angles, all carbide and SN, and it only fell an inch, you're fine.