Good evening,
What is the best way to measure threads on the CMM? I would just use a thread gage and put it in the report but I was asked to write them in the program. Thank you in advance.
When I measure threads I select a tip large enough to not "fall in" and I take a few linear scans along the direction of the shanks vector. I can't say that this is the best way, just how I do it.
IF you want to measure thread position, possible, big ball and correct pitch in the autofeature is right way
but for thread itself CMM is not the correct tool. how big is the thread ?
The CMM is not the correct tool to measure the major, minor, or pitch diameters. For the location, I would recommend using a thread locator. That's what we use when we have tight position callouts on threads and they will repeat much better than probing the thread itself.
The last place I worked had thread locators and they worked well. What they ae trying to do is take the operator out of the equation. But, golly. they have to do something other than push a button!
Until you get a bad thread locator. They have tol. when they are manufactured as well. I had a large part with a dozen or so locators and a few of them were junk. Of course it took awhile to figure out what the exact problem was..
When it comes to reporting true position of threads do you leave out the dia of the thread? If you do report the dia what is the tolerance? Do you just use the nominal dia pcdmis comes up with? There are a few different ways that people have programmed threads. Some left the dia out and just reported the position and some reported the dia with a tolerance. I just cant seem to figure out how they came up with a dia and tolerance.
