Repeatability issue

[Datty]

Hi everyone,
I am very new to CMM programming and to this forum, too. I am having an issue of repeatability of the CMM. Every time I relocate the part, it will give a different result. Would anyone of you out there please show me the right way to program this so I can get a better repeatability on thi part. I also include .pdf file. Thanks in advance.

Datty

[cmmguy]

Manual datum reference frame then repeat under DCC then measure your features...

[John Kingston]

cmmguy is right. Align to the datum scheme manually, then repeat in DCC.
Can you post some of the program? Particularly the part you are having issues with.

[than_357]

Some more information would help, as mentioned before, and an idea of how much repeatability you have (or don't have) and want would too.

Double check for burrs, dings, scratches, etc. Same with probe tightness, cleanliness, etc. Make sure your alignment is really aligning what you want and in the right workplane.

Not fond of the TP callout for the pins, but then it isn't my print either....

Good luck

Tom

[#2#]

A couple of things to note...

Heed all of the above. Proper alignment will fix many things.

You don't mention how unrepeatable you are. A few tenths? Your machine probably won't do better than that - ever.

I don't know how your part is set up or how your program runs but the squareness of the part setup to the machine can cause non-repeatablility due to shanking on hits, messed up alignments, etc. I always make things as square as I can - within reason.

Lastly, it looks to me like it is a pretty small part. I don't see a material. If it is metal it is most likely pretty stiff (I am guessing it is metal). If it is plastic, your clamping/holding method could be deforming it. Also, your clamping/holding method could not be adequate which would allow the part to move and cause nonrepeatability.

[AJHVW93]

Are You Using Same Touch Speed On Cal And Measurement???

[John_K]

What results are you getting in your probe cal?

If you are not repeatable there, then the rest will noot repeat.

Which version are you running?