ASME Y14.5-1994 Profile of Form

[looslib]

One of our design groups is using Profile of Form for the shape of the part and then dimensioning the whole part with basic dimensions. I haven't seen this before, how common is it to use this method?

The group I normally work with uses an unspecified tolerance chart and normal diminesioning. With our designs in metric, we don't use trailing zeros so this has caused us some problems with manufacturing. Over the years the designers have gotten used to toleranceing dimensions that need it.

If I took a print of the same part and asked for a quote to build, would I get the same price? I think the drawing with the basic dimensions on it would be a higher price because of perception.


"Wildfires are dangerous, hard to control, and economically catastrophic."

Ben Loosli
CAD/CAM System Analyst
Ingersoll-Rand

 

[DATUMDON]

It is comman to do this however it is not necessary because the math model is basic (nominal, 0.0 tolerance).But its OK to introduce BASIC dims because they are non-accumlitive & you introduce basic dims from any feature to any other point on the part. BASIC dims are the theoretical perfect point, position or profile. I know this does not solve your intire problem but it is a start. Would you like to hear more? (devans@thetford.com)