CMM Reference?

[Underspec]

Looking to see what you all use for dimensional referencing on the CMM. By that I mean what else do you use other than the calibration sphere?

I'm looking at something to "prove" that the CMM is measuring accurately .

[Matthew D. Hoedeman]

Try checking some jo-blocks. They may not cover a lot of space, but they sure should be accurate!

[bw_bob]

WMS......gage blocks,gage pins

[\v/inston]

i used to work with a guy named joe, he had his own set of jo-blocks. he carved in the top of the box "joe's jo-blocks".

[Mike N.]

i once knew a guy from Nantucket....

[John Kingston]

Gage blocks, ring gages and a "standard part". See some of Hilton's posts about this, it is a subject that he is very well versed in. He has written an outstanding paper on this subject.

[Paul Sarrach]

Gage Blocks are good. Also, check something that has been 3rd party checked. Then find a part make a program, call the results master. Do a cap study on it. Then save it as Master. Any time you have any doubts, you can throw that part up and compare your results. It its the same, great if not problem. I like to do this right after the Machine has been calibrated.

[HK-MFGNET]

H & K makes just what you're looking for visit our website www.hk-mfgnet.com
(I don't mean to be selling here, just offering info)

[Paul Sarrach]

This is pretty cool. How much?

[smudge]

not trying to sell this but seems very good, manufactured by inora and called spacial reference system (srs) can be used on machine tools and cmm, various sizes have a look

[\v/inston]

not trying to sell this but seems very good, manufactured by inora and called spacial reference system (srs) can be used on machine tools and cmm, various sizes have a look

too many shanks. look cool though.

[dwade]

Thought I have not used one, I think the Glastonbury Quik Chek would be the best IF want to verify all of the geometric maesurements and calculations for your CMM and software. Angularity, location, size, length, distance, etc.

I think they are a little pricey but understand that if want to know what your CMM actually measures, it is the best way to go.

[dccfreak]

how about making your own step gage. My CMM calibration guy suggested this for me and it worked out great. I have a fully tooled machine shop with CNC and such so it was easier for me than it might be for others.

All you need to do is get a 18 inch by 1 inch square bar made out of stainless steel, then have holes put in at 1 inch centers so you can have a step gage. According to the tech, this will let you know very easily if you have any accuracy issues. That is what he uses when he certifies my machines along with the ball bar test. But he said the step gage would cover your linearity, and will catch issues with pitch, roll, and yaw.

It's also pretty inexpensive to make when you compare to most artifacts at 1200 - 3000 dollars. I believe the step gage cost us about 300 dollars to make.

Or, I also use an old obsolete part gage that I had certified to the design print at an accredited lab. Whenever I have questions, I just whip it out and compare my results to the certification results.

I have to do stuff cheap, so I thought I would just throw that out there.

[terry]

I couldn’t get the powers that be to fork up the money for an artifact so I made one out of a scrap part. I bought 6 gage balls for $15.00 each and used epoxy to glue them to the part. Wrote a program and used two probe angles per measurement and ran it 31 times and recorded the average size and location of the balls. I then changed the nominal to this average. Part repeats with in .003 mm. It may be ugly but if we have a crash or something it will give me an indication that a service call needs made