Scanning an extremely rough circle

[[Za...]]

Hello all, I hope everybody is doing well during this crazy time in the world.

I'm trying to figure out the best way to scan this rough bore. This is a cast part that has a starting dimension that is from this rough bore. The issue is that the bore looks awful and clearly isn't round. I don't want to attempt to scan it just yet, because I think it could cause a crash and/or could break/damage the probe. Does anybody have any suggestions on the best way to go about measuring this bore?

[[To...]]

I would probably resort to single points instead of scanning.

[[Me...]]

I agree with single points if you're going to try and use the CMM to measure it. I'd evaluate it as a Max Inscribed to find the center.

I'd probably stick the largest gage pin in it that will fit and measure that.

As a general rule, I almost always use single points on cast surfaces. Scanning them tends to damage your probes over time.

[[Jo...]]

Depending on stylus, you could use unknown contour to slowly scan it.

[[Za...]]

Please sign in to view this quote.

I had to re-fixture this and start over, so when I do it this time, I can try that, but I've never used the unknown contour feature. Do you have any suggestions?

[[Jo...]]

Please sign in to view this quote.

I think you can access it under strategy in circle feature. Another option may be a slice thru model as curve..It was demonstrated in the advanced course but I haven't used it either.

[[To...]]

If you're using an active sensor, scanning a circle at slower speeds will work pretty good, too. Passive, not so sure.

[[Mi...]]

I'd use a 3 pt circle and pick the best landing spots, but I'd also be tempted to ask the engineers if I could use the port hole instead and do a concentric evaluation on the casted hole to prove that it is where it should be. Might get lucky.