Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations IDS on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Angular True Position? 2

Status
Not open for further replies.

trickysheep

Industrial
Dec 17, 2004
12
I am a little stumped here. I have a part which we laser etch 3 small rectangles onto. The laser etching is called off of the centerline of the part, at 12 1/2 degrees 3 places. It has the true position box around it. The only tolerancing on the pads is a width of .120 +/- .020, and a box which gives .030 max material. How can I transfer this to an angle and find where I am?
 
Replies continue below

Recommended for you

They can not reject the part based on the 12.5 degree being out of tolerance with the tolerance block. The very fact that the angle is basic excludes the standard tolerance block. They can reject it based on the fact that it is miles off of the positional of .030 though. This drawing is way off but the way the datums precede the tolerance in the FCF tells me that this was drawn to conform to the 1973 ANSI standard.
Here are the issues I see with this drawing:
1.Where one pad is shown located from the center (of what?) using a toleranced dimension, that's wrong. Positionally located features are always basically related to the datums.
2. The .390+/-.070 dimension is located using position. This is also wrong as only features of size are positionally located. Profile would be a better choice for those particular features.
3. The diameter symbol in the FCF is not correct as pointed out by KENAT. There also needs to be a tertiary datum to orient the pattern. What is there is not sufficient.

Unless the 1973 standard actually allowed these kinds of things, I'd say you have a pretty bad drawing you have to deal with.

Powerhound, GDTP T-0419
Production Supervisor
Inventor 2008
Mastercam X2
Smartcam 11.1
SSG, U.S. Army
Taji, Iraq OIF II
 
I think you have BIG problems. First, you really need to know what version of Y14.5, IF ANY, applies to this dwg!!

There are so many areas of concern. Not necessarily in order of precedence. Mixing of Pos and Bilateral dimensions to locate the etching. Applying a material condition to the etching. (Don't understand that at all). Applying .000 mmc to a Tan PT???
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor