scanning in threaded holes

[[je...]]

I would use a thread gage of which I know the distance from the center of the lead thread to the end of the gage (i.e. 2.000"), install the thd gage. Measure a point on the end of the gage and on the face from where the depth is specified then using result element subtract the height measurement from the known length. I use gage pins when the hole is not threaded.

[[ed...]]

How about linear scans while constraining the normal vector?

[[Ri...]]

Unless it's a short hole, why would you constrain it?

If you are dead set on linear line scans, go slow with a small step width, and use outlier elimination to get rid of the points where the probe falls off the tip diameter. Typically a 1/3 outlier elimination, and 3 iterations will do this for you.

[[Ri...]]

Self centering isn't possible with the Vast XXT is it? 😐

I'm currently in the unenviable and expensive position of having to buy TP plugs for my small diameter threads as they are eating all my .5mm probes. At nearly 300$ a plug gage its a hard sell.
(M1.6x0.35-6H and M2x0.4-6H for example)

I swear that 4 point thread macro is nothing more than a sales tactic to sell stylii. Steer clear!

[[Ri...]]

You can only self-center with the XXT in the Z direction. It will allow you in other directions, but since it is a passive sensor, the results aren't the same as with the active sensors.

Regarding your 0.5mm probe situation, I would strongly recommend you to look into diamond probes then. There isn't an M3 XXT native diamond probe of 0.5, but I am certain (since there are 0.5 in M5) that they will make a custom one for you. This will save you costs, and increase your throughput (since you don't have to use TP plugs).