DRAWING COMPLEXITY

Hi folks. My company is relatively new (3 years) into the 3-D world. We design various cast and molded parts. Since may of these parts tend to rather complex I wonder how detailed the drawings have to be. More specifically, I'd like to hear from people who manufacture similar types of products to know what information is given on the drawing and what information is gotten from the solid model itself. Many times I find myself spending almost as much time creating the detail drawing as I did creating the model.This almost appears to be counter productive.
Thanks a lot for any information on thios subject.

Jack

When it's very complex (rounds, blends, complex surfaces, ...) there is no way to detail the product and you probably are transferring the information digitally (you should be). When transferring models to other people I will make a drawing that only details these items that are important and have to be checked to make the product functional.


Alex

You have just touched on the fundamental issue of the 21<SUP>st</SUP> century. If your product is manufactured in-house, then your drawings can be any way your technicians/mechanics want to see them. If you outsource your manufacturing, then your drawings will need to be as your vendor wants to see them.
The ASME 14.41 standards are attempting to homogenize the solid model regarding dimensioning, tolerancing and minimalist drawing sets. There is a large movement towards paperless prints in the industry. It

I too design complex castings and it is not possible to define surface geometry with 2D drawings. I don't even bother with tolerances on the drawing - it's pointless. We just include a general tolerance for casting e.g. 0.005/linear in. If the model (after shrinkage allowance) has been used to cut the mould then there is little the toolmaker can do to control tolerances of the finished part. More often than not we can live with slight deviations from the desired nominal sizes - we always aim to build this aspect into the design so it isn't so critical so as to affect function of the part. Regarding dimensioning - we always dimension criticalsizes - flanges, hole positions etc, but for complicated geometry you can only do so much as AHA-D points out. the rest is inherently stored in the solid model so the moulds will include all the details of your model.


Phil