How to measure circular runout of an internal thread?

[Kingbob]

I'd try to loop in someone from engineering at your customer. When dealing with an idiot in QC you can try arguing with the idiot (which if he could be educated he wouldn't be an idiot) or circumvent him. Hopefully the part rejects effect them enough for to them to try to be part of the solution.

 

[camhead420]

I noticed in your original post you have rectangular block, fixtured.
How are you doing both threads at the same time? Do you have a 2nd operation for the threads on the other side?

 

[Dan from Oakland]

Customer QC guy sounds like he needs a good beating. Contact their engineer and let him decide how it needs to be checked.

 

[implmex]

Hi All:
I notice a lot of the commentary offered starts with some variant of "The QC Guy is a fucking idiot"
I agree fully, but that's not helpful.

The OP has a decision to make:
Is this customer worth keeping for other reasons than just this job?
A) If yes, he has to find a way forward that will satisfy the moron.
B) If not he can blow him and the whole job off and tell the QC guy to his face what a dick he is.

Choice A he keeps the customer.
Choice B he does not.

Since Dickwad has advised the OP that he (OP) has to take responsibility for hauling Dickwad's ass out of a sling of his own making...that's where ya gotta go.

I like the Vermont expanding Jo plug idea pictured above because you can buy it from the store and it's made to a standard only a moron will argue against.
Oh wait...we already established Dickwad is a moron.
Float it past him anyway...even buy the gauges if you think it's worthwhile, and make sure you copy his supervisor when you send him the email advising him of your solution.

Make sure you test it first so nobody get's an unpleasant surprise.
Video document some "rejects" so nobody sane gets to argue.

That oughtta fix him!

Cheers

Marcus
www.implant-mechanix.com
www.vancouverwireedm.com

 

[Mr.Chipeater]

Hi All:
I notice a lot of the commentary offered starts with some variant of "The QC Guy is a fucking idiot"
I agree fully, but that's not helpful.

The OP has a decision to make:
Is this customer worth keeping for other reasons than just this job?
A) If yes, he has to find a way forward that will satisfy the moron.
B) If not he can blow him and the whole job off and tell the QC guy to his face what a dick he is.

Choice A he keeps the customer.
Choice B he does not.

Since Dickwad has advised the OP that he (OP) has to take responsibility for hauling Dickwad's ass out of a sling of his own making...that's where ya gotta go.
View attachment 392421
I like the Vermont expanding Jo plug idea pictured above because you can buy it from the store and it's made to a standard only a moron will argue against.
Oh wait...we already established Dickwad is a moron.
Float it past him anyway...even buy the gauges if you think it's worthwhile, and make sure you copy his supervisor when you send him the email advising him of your solution.

Make sure you test it first so nobody get's an unpleasant surprise.
Video document some "rejects" so nobody sane gets to argue.

That oughtta fix him!

Cheers

Marcus
www.implant-mechanix.com
www.vancouverwireedm.com

That's a good idea. Unfortunately they don't stock UNEF threads, I'd have to order a special for a 5/8-24 thread. I wonder how much that'll cost...

 

[Houndogforever]

Probably less than all those scrap parts.

On a more helpful note, perhaps cut 1 out of every 20 in half and measure. Do statistical analysis of the process to show that the parts are good.
If the process proves good via destructive testing, then move up to 1 in 40 etc.

 

[gregormarwick]

They have a gauge ring that (presumably) has an ID concentric with the (presumably nicely ground) thread on it's OD.

First, enquire of them if this gauge is calibrated for pitch accuracy, thread form, and concentricity of the gauging surfaces.

Second, you have a part with a convenient shoulder below the thread that needs to be gauged. A simple compression spring in the hole before the gauge ring is screwed in will hold the gauge ring against the thread flank, centralising it properly on P.D.

This is a very minor adjustment to their existing procedure so shouldn't be difficult to make it fly with them.

 

[CarbideBob]

Are you the first place ever in the world to make these parts?
Was anyone else able to pass this QC check as it is being done?

 

[johansen]

They said "that not how its assembled so its irrelevant." They then explained that the part is assembled by screwing in 2 different pieces into each end, then a rod is inserted through one piece, through the center bore, and out the other end.

And who makes those parts?