Drawing Exercises

Drafting experts - do we really need to show every single dimension on a related paper drawing?

I work with an engineer who thinks it's 1940. Previous companies I've worked at allowed solid models to define parts with only the critical or inspection dimensions required on the paper drawing. He wants every single dimension on the paper drawing, but that takes much longer, plus is less acurate because changes to the model don't always correctly update on the drawing. Does anyone have a book or magazine article showing that solid models are acceptable for part definition? Thanks in advance. Oops - Meant to have Solid Models referenced in title, but crappy yahoo answers isn't working when I select edit question

Public Comments

1. I don't have an article reference, but I am a mechanical engineer and I create drawings in ProE and AutoCAD. One of our machine shops will accept model files from ProE if you give them a drawing with critical dimensions, as you said. The other shop doesn't have any computers, just machine tools, and needs every dimension from datums with tolerances or you might not get what you thought you drew. It really depends on the shop's capability, and if you can get their buy in you should probably be able to get a big wig to update company policy regarding the practice. Stress the idea that it's cost saving and show them why with a big complicated drawing with tons of dimensions that could be eliminated by using a model.
2. Maybe he does not understand that the solid model is only a preliminary drawing showing the functionality of the end product. You may try to explain that this is intended to act as a mockup so interference and clearances can be identified and changed. Once a design is finalized it maight be better to look into a more detailed solid model.