Hello All,

I am a recent graduate and a young Junior designer. One problem that has plagued me for a while is what best practices to use when surfacing for injection moulded parts. I'm familiar with the old design-draft-fillet order of business, but I am still running into some troubles.

I've heard many people say "thicken your surfaces first, then add fillets" to avoid thickening (or shelling) errors of "minimum radius of curvature" creating self-intersections on the inside of the part. My question is this: what if I'm not using fillets to create these tight radii? I often use lofts or boundary surfaces as they provide more control over the surface when creating parts. These inevitably create tight radii in some areas that fail when thickening.

Am I doing things in the wrong order? Or perhaps using the wrong tools? I just spent several hours using offset surfaces, extending edges, trimming, and face filleting to thicken my parts. Very painstaking and inefficient, any feedback would be great, and I suppose I could provide a model if necessary.

JDM