go nogo gages for precision machining features

[bxbzq]

Hi,
There are some parts in my project have precision machining features like φ20H7(0, 0.02) holes and φ20(-0.06, -0.02)) rod. Given the tight tolerances of these features, does it make sense to make go nogo gages for these features? If yes, what tolerances should the gages hold? We are not going to pay crazy prices.

Dennis

 

[MikeHalloran]

How many thousand units will you inspect in a day?
What is the inspectors' skill level?
Answers to questions like that might help you decide what to do.


Crazy prices can be an indication that a vendor just doesn't want to deal with you any more.
You might want to think about why.


Mike Halloran
Pembroke Pines, FL, USA

 

[3DDave]

You need to hold tolerances that will give you the yield you want, but without accepting more out-of-spec parts than your customers care for.

This is a statistical analysis problem without a simple answer.

 

[drawoh]

bxbzq,

I have heard a crude rule of thumb, that gauges should be ten times as accurate as the feature they are measuring.

Another rule of thumb which actually is quite accurate, is that go[ ]gauges inspect each and every feature of the things it should pass through. Each no-go[ ]gauge inspects one feature, only. You may need several of them.

--
JHG