Metrology equipment for lab

[drodrig]

Hi there,

We are setting up a small workshop with a drillpress, tools, benches, cutting machines... in order to be able to do small tasks. For more professional parts we have a mechanical workshop with experienced people working there (with lathes, milling machines...).

I've been thinking about getting measuring machines to check machined parts (or even some composite components we make).

What would you recommend to set up a small metrology lab?

- CMM machine
- Roughness surface tester
- Dial indicators/supports..

thank yo
regards,

 

[Belanger]

Depends on your budget (no surprise, right?). I'd start with a granite surface plate and dial indicators, a height gage, sine bars, digital calipers, and other manual equipment. If you have the cash, a used CMM is great but that requires specialized training.

John-Paul Belanger
Certified Sr. GD&T Professional
Geometric Learning Systems

 

[dgallup]

I second the above but would add an optical comparator before a CMM. Budget is everything. Size and quantity of parts to be inspected is next consideration.

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[drodrig]

Thanks for the answers.

Does the CMM need a lot of training?

With the Optical comparator it seems one can not measure perpendicularity, parallelism... it seems a bit limited.

My point is we paid 700 euros per part to a company for precisely measure two parts. With 80 of these measurements (ok, a lot, but in a long ternm) we can already pay the CMM

cheers,

 

[MikeHalloran]

Yes, your future CMM operator will need some training. It would be better to start with someone who already knows how to use traditional measuring tools, rather than sending some minimum-wage wharf rat.

The CMM will also need a conditioned room and a service contract.



Mike Halloran
Pembroke Pines, FL, USA

 

[3DDave]

Were the parts inspected on a CMM? I would expect that the cost included reading the print, making a plan for inspecting the part, programming the dimensions and inspection procedure into the CMM and then doing the inspection, upkeep of the CMM, upkeep of the room the CMM is in, plus profit. You can save some of that, but I'll bet it won't be all of that.

Since the original spec didn't include photos of example parts or drawings of same, it is hard to know what may be valuable to inspect them. That's why the optical comparator was mentioned. It can be used to verify items that a CMM cannot do, but if you don't have parts that need it, there's no reason to have one.

 

[mcgyvr]

pin gage sets and a digital caliper...
Provide more details and better/relevant suggestions can be made

 

[dgallup]

You said small shop to do small tasks. Optical comparator is a better fit for that than CMM given limited info. There is about an order of magnitude difference in the cost and training required.

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[TED7]

Don't call it a "CMM machine" you will burn in hell in metrology circles for that. It's a 'CMM' or a 'Coordinate Measuring Machine', not a 'Coordinate Measuring Machine machine'.
Also, CMMs are alright but unless you know what you're doing with one and the limitations of only measuring points, you can make a right mess of measurements.
A pair of go not-go pins or a bore gauge is going to do a far better job of measuring a hole than someone who thinks they only need two points on a CMM to measure a hole diameter.

 

[drodrig]

Yes, CMM Machine is redundant.

Here a picture of one part we produce, carbon fiber coming out of a mould:

We have moulds with very high accuracy and we want to measure the result (this part was sent to a company to be measured and the measurement cost around 1000 euros)

Here half of the mould (when full it has a square shape). We need to measure it when mounted to see if the mechanical workshop did well their milling work

If we want to see how flat are the faces, also how much perpendicular; I understand we need CMM

cheers,

 

[IRstuff]

Something is horribly NOT flat in that last picture.

Seems to me there are several ways besides a CMM for measuring flatness:
> laser or mechanical profilometer
> dial indicator
> optical flat

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

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[drodrig]

in the inner faces of the "L"?

 

[IRstuff]

The near left and rear right corners are off the tabletop, so either the table top is not flat or the part is not flat. There's a lot of FOD on the tabletop, so that could be it as well.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

https://www.youtube.com/watch?v=BKorP55Aqvg

faq731-376 forum1529 Entire Forum list

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[3DDave]

This is the part with the aluminum cores held within the depicted steel jacket during a heated cure.

Generally, measuring flatness with a granite plate, a height gage / indicator stand and a dial indicator would be easy. Perpendicularity can be verified using a machinist's square and a feeler gauge.

However, since you haven't specified the precision you want, there's no way to know if a cheap setup can attain that goal.

 

[3DDave]

Here's the original thread

http://www.eng-tips.com/viewthread.cfm?qid=415893

 

[tbuelna]

The costs involved with a CMM are probably far greater than you imagine. With the composite part shown, it is often acceptable to inspect the tool and a first article produced from the tool using a controlled process. The subsequent parts are accepted based on use of the controlled/validated process and the qualified tool.