Hello!
Could you tell me please how do you measure positional tolerance for thread?
The idea of measuring spirally less and less do i like because for my experience big different measuring between threaded hole and without.
Using cilindre prob good idia for circule, but for cilindre i am not sure that surfece of cilindre prob can correctly measuring points.
How do you measure?)
I measure a cylinder and specify a pitch. The pitch equals the thread pitch in whatever units the routine is in. I dimension position only and ignore material modifiers. You can add 3 sample hits to make sure you are always probing the same points in the thread.
If I had an analog scanning probe I would create an adaptive cylinder spiral scan, pitch is the same as the TTP setting.
I use LaVezzi thread locators whenever I have a tight tolerance on thread location. PROS: They are accurate, they repeat very well, and are easy to use. CONS: they're expensive and you have to be careful not to move the part on the CMM when putting them in/taking them out. They increase runtime as well because you have to put them in/take them out