Press to Flush call out 2

[rschatz]

What is the appropriate callout/standard to use when calling out a pressed in plug? We would like to press the plug Flush and have a tolerance for under flush. We know our current callout is incorrect.

 

[drawoh]

rschatz,

A profile tolerance works nicely here. Use the bottom of the hole as a datum.

JHG

 

[MikeHalloran]

Yes, parallel is not, e.g. coplanar.

A normal note would read something like 'flush to .005" underflush' or something like that.



Mike Halloran
Pembroke Pines, FL, USA

 

[SeasonLee]

Yes, a note of flush and an enlarged sketch of that portion is a good practice.

SeasonLee

 

[hydtools]

We have used the bottom of the large bore as datum and dimensioned the plug surface .000/-.005, for example. Show the plug in non-flush position. An enlarged view is good to use.

Ted

 

[dgallup]

I really like drawoh's use of a profile tolerance because it clearly shows which way you allow it to be offset from flush. Otherwise I think it can be open to interpretation.

 

[MechEng2005]

At first I thought I agreed with hydtools... Then I started thinking about putting it in practice. In order to make sense, you would show the plug pushed .005 underflush (to show direction) and the dimension would be between surfaces would be .005 with a tolerance +0/-.005. Or perhaps it would be more clearly indicated with limit dimensions (0.000 to 0.005).

However, I think if the design intent is to have them flush, with some "under flush" acceptable, it would be clearest just to show an enlarged view with the plug 0.005 underflush and dimensioned as ".005 MAX".

That's my 2 cents. (Don't worry, I'll start a tab for you.)
-- MechEng2005

 

[JMarv]

...it would be clearest just to show an enlarged view with the plug 0.005 underflush and dimensioned as ".005 MAX".

I agree that this would be the clearest way to define it. I've also seen instances where limit dimensions were used as you mentioned.

Joe
SW Office 2008 SP5.0
P4 3.0Ghz 3GB
ATI FireGL X1

 

[PeterStock]

With ".005 MAX" if the plug was pressed to .005 above the surface, then the vendor could argue that it was not more than .005 below and thus to print. I would think he was wrong, but ".000-.005" states the intent better.

Peter Stockhausen
Senior Design Analyst (Checker)
Infotech Aerospace Services

http://www.infotechpr.net

 

[KENAT]

I've actually taken to showing the items under flush and giving the dimension and tolerance.

Intuitively the 'MAX' seems appealing until you get the situation Peter mentions.

Also at the end of the day, you can't really have an implied 'preferable end of the tolerance range' which is what you're trying to do by saying 'MAX'.

Either .005 underflush is OK or it's not.

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