CMM capability

Hello,

Need expert opinion...

I have a Mitutoyo Bright BRT910 with a Renishaw PH9 probe.

I need to measure datum A bearing journal to opposing datum B bearing journal that are spanning approximately 24.4” from each center point of journal, the bearing journals are approximately 1.10" in length.

The dwg has geometric control for True Position .01, Parallel .003, Datum B reporting to Datum A.

Q: is the CMM hardware/CMM manager software capable of making accurate measurements per the geometric callouts on the attached dwg?

It looks to me that there could be too much error being that the bearing journals are so far apart.

Regards,
KincadeM

How do you intend setting it up to measure?

I can't say with certainty that your particular machine can measure the features accurately. Gordon mentions one aspect of the answer, and the others are as follows:
-Does the CMM have the travel envelope to measure the part end to end?
-Has the CMM been calibrated and is known to be functional to its own accuracy specs?
-Does the PH9 head have an indexable probe tip, such that you can take a number of points around the bearing journals?

If the answers to these questions are all "Yes", then I don't see why you wouldn't be able to measure the part to the accuracy of the CMM and the stability level of your setup. If I were doing this, I would plan to take a number of points (or scan circumferentially if your machine can do that) on each journal to get a very complete picture of the geometry of the features.

FYI, side note: If I were you, I would avoid posting customer drawings with both the customer name shown as well as the note about proprietary/confidential information.

I would see getting a good alignment being key to an accurate measurement on a CMM. As much as I like my CMM and all it can do, I think this is a part that can be checked in under 2 minutes between centers with an indicator.

Larry Dickman said:

I would see getting a good alignment being key to an accurate measurement on a CMM. As much as I like my CMM and all it can do, I think this is a part that can be checked in under 2 minutes between centers with an indicator.

Click to expand...

Makes me think of something that still makes me smile. I visited one company that was measuring parts with their CMM and could be done faster with an ordinary height gauge. When I asked why the reply was, "Our boss doesn't like to see it stand idle".

I'll go with no.
Orient makes no difference but your machine and probe will not do the rule of ten here.
You can and should reduce your checking tolerance by your known and tested gage R&R but you may run out of headroom here.
If the above makes no sense can I go with never trust a CMM?
Bob