Datum and POsitional Tolerance on Hanger/Hook 1

[coolchincy]

Dear Fellowmembers,

First of All, I would like to wish All of you a Very Happy and Successful New Year!!!

This is my first post, so please be gentle and helpful.

I am currently working on a drawing for a hook/hanger. Main application for this hook is to hang weight in central axis(LINK:

http://files.engineering.com/getfil...d6a7-40b3-aaf4-a1cfe9611a62&file=Hanger.PDF).

I do not want any overbend, underbend or twist while manufacturing this part.
I need at least 2 more datums but struggling to define it.

Any suggestions and guidance is highly appreciated.

Many Thanks
C

 

[pmarc]

Look at link below. It shows a technique that should work for you. In your case you will be having only one diameter as a datum feature, not two as in the tip. Together with upper face of the hook (most likely as a secondary datum feature) they will help to create reasonable datum reference frame. The crux is to define true shape of bend with basic dimensions relative to defined datum reference frame and use between-two-points method for positional tolerancing.

http://www.tec-ease.com/gdt-tips-view.php?q=128

 

[CheckerHater]

Also, if you work to ISO, you do not have to use words “EACH ELEMENT” as your size is local size by default.

 

[pmarc]

CH,
I do not think "EACH ELEMENT" note has something to do with size of the tube in this tip. It is to indicate that positional tolerance applies to each cross-sectional element between points S and T (though in my opinion BETWEEN symbol is fair enough).