Long Bore

[[Du...]]

Does anyone have an idea on how to check this? Part is roughly 44 inches and my granite block is only 40 inches long.
Running this on a Contura 7/10/6.

[[Ju...]]

This post has a guide concerning what's called "leap frogging" for when a part is longer than the measuring space available.

viewtopic.php?t=3147

[[Ia...]]

Have you tried setting up diagonally?

[[Ri...]]

I don't think I'd recommend leap-frogging to hold a 0.002" Position over that kind of length.

The only way, short of using a much larger machine, is to create what I call a hook-back stylus, but I don't think it will be possible on your size of machine.

You could always reach out to us, and we can easily handle this job for you. We have a lot of experience measuring long tubes like this, and I feel like we've measured some of these exact ones. 🙂

[[Mi...]]

Dustin,
Is your issue with the part being larger than your bed, or with trying to measure a 32" deep bore? Everyone's talking about leapfrogging, but even if you had a larger CMM and didn't need to leapfrog, I wouldn't know where to begin with probing that whole ID.

[[Du...]]

Both, From what I understand the customer runs this on a much larger machine than mine, and check the datum from one end and the feature from the other end. My machine isn't anywhere near big enough so I was asked to attempt running both from the datum end.

[[Ow...]]

Stating the obvious but, you'd have to have vast head to use a probe that long, Vastxt 500mm max[19.6"] or Vast Gold 800mm max [31.4"] so on a big enough CMM it's doable but, how do they check that 32 surface finish that deep?
A bigger CMM aside, the guy's/gal's at precision devices could probably do a custom made Bar Arbor Sweep gage but, it wouldn't be cheap.
https://www.predev.com/sweep_gages.php

[[Du...]]

we have a vastXT, the current setup looks to be about 762mm so I think accuracy has probably been thrown out the window.
As far as the 32 finish we have a Zeiss handy surf, very useful for deep bores.

[[Re...]]

You could use a U- shape stylus system to reach into the bore. Several years ago I had to do this on a bore from each end where the leap frogging method would not work. I was able to expand the working volume by some 300 mm.