CMM Sphere Qualification
CMM Sphere Qualification
(OP)
Do you perform sphere qualification everyday or once a week or....?
I have told that instead of performing sphere qualification-->stylus qualification, they would perform size check, such as using a gauge ring and perform a "daily check".
Not too understand the theory behind this.
I have told that instead of performing sphere qualification-->stylus qualification, they would perform size check, such as using a gauge ring and perform a "daily check".
Not too understand the theory behind this.





RE: CMM Sphere Qualification
Mike Halloran
Pembroke Pines, FL, USA
RE: CMM Sphere Qualification
RE: CMM Sphere Qualification
Mike Halloran
Pembroke Pines, FL, USA
RE: CMM Sphere Qualification
RE: CMM Sphere Qualification
Mike Halloran
Pembroke Pines, FL, USA
RE: CMM Sphere Qualification
Daily "checks" can be useful, especially if the CMM is accessible by many different people, not just one or two specific CMM operators. For instance, when I worked as a QA tech, we had QA personnel present for first shift, but not for second. The first task each morning was to clean the CMM table and run a short probe check for each probe (there were only 3 commonly used configurations.) This check was short (5-10 minutes) and made apparent any significant change to the machine and/or probe conditions. In my experience this was infrequent, but when it occurred it was usually from a part being fixtured incorrectly (leading to auto-drive into the part) or an operator accidentally driving a probe into a part. The morning check was a quick way to see if there were any big changes in machine performance without consuming too much time. It certainly was not make-work.
But for someone else's operation, it may be totally unnecessary. Your specific quality requirements and experience with your CMM's capability, reliability, and workload will determine the qualification / checking frequency.
RE: CMM Sphere Qualification
2. For Daily check do you use ring gage (setup with three different axis) to check different axis?
3. Is this daily check tends to check the probe or the machine or both?
4. I think one of the reason to perform sphere qualification is because wear, due to measure too many parts. 24hrs run.
5. Of course, if there is a crash due to malfunction or operation error, sphere qualification has to be perform.
6. I am hoping that you could share more information how you perform the daily check/criteria.
RE: CMM Sphere Qualification
I haven't ever seen us use a ring gage check.
Wear has never been an issue for us, as we don't typically use the scanning function and the machine isn't subject to 24/7 usage.
An outside calibration of the CMM itself, including laser alignment and some other stuff more complicated than I ever got into, is performed at a set interval (one or more years apart.)
Remember though, that your checking and calibration requirements will be different than mine. We're typically inspecting components for use in industrial products that rarely, if ever, are in life-critical applications. Further, any government-related work with more stringent quality requirements prompts a more thorough CMM inspection and qualification prior to part inspection. If your product has very tight requirements or is used in more critical applications, then the functional requirements of your CMM are different and require a different inspection/qualification routine. You will have to, through experience, determine the minimum level of machine inspection/maintenance required to assure manufacture of parts that consistently meet your approval criteria. You may find that your procedure needs to be modified after some time.
I hope this was helpful.