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Basic Dimension 1

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Valek

Mechanical
Joined
Oct 27, 2006
Messages
8
Location
US
Hello,
Can you dimension a thickness dimension as a basic dimension.
Say you have a flat (strap) part 6 inches long with 2 holes on each side 1.0" from the edges and a profile surface call of .002" on top face datum A. Why would you use a basic dimension on the overall thickness.
You can control this call with a close tolerance or with a max- thickness, correct?
Can Y14.5 allows you to use a basic in this case?

Thank you.
 
Yes, that is OK. The basic dimension is the "basis" for the profile tolerance to be applied around.

John-Paul Belanger
Certified Sr. GD&T Professional
Geometric Learning Systems
 
Yes, you can use Thickness dimension only, or profile symbol without datum, or profile symbol with datum (in this case you have to use basic dimension).
The results will be slightly different though.
Please see enclosed picture.
 
 http://files.engineering.com/getfile.aspx?folder=498d4e7a-eddc-48a4-b35b-dcfda140abd7&file=profile.JPG
Referring to what J-P said - basic dimension is OK, unless this is stock material manufactured to any kind of standardized thickness. There is this fundamental dimensioning rule saying that:
"Wires, cables, sheets, rods, and other materials manufactured to gage or code snumbers shall be specified by linear dimensions indicating the diameter or thickness. Gage or code numbers may be shown in parentheses following the dimension"

Valek,
Out of curiosity, when put on a flat table, would this strap have a tendency to roll up? In other words, can this part be considered as rigid?

CH,
In your last picture (bottom right) I guess you meant +/-0.5 not +/-1, right?
 
pmarc,
Yes, sorry,
Always in the hurry when posting from work :-)
 
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