From:  steve (STEEVE)
Project: to model a sheet of 3mm plastic with letters formed into it via a vacuum molding process

Well this was fun.

First, even tho I've done a fair bit with MoI, thanks to Brian I now know that MoI has very versatile text capabilities! I had never noticed that before :)

In fact there are many ways to approach this project.

The best I've found so far:
place a letter as a 2d curve on the sheet surface
form an 2mm offset outside of the letter
extrude the outer curve 2mm up
extrude the inner curve >3mm down
boolean union sheet to outer extrusion
boolean subtract inner extrusion from the rest
apply fillets as required

Another method involved placing a solid letter on the sheet, shelling it and then finding myself in some strange inverted space where booleans produced unexpected results!

I noticed some of the operations took a long time. For example filleting the upper face of the S took about 18 sec, and the internal corner where the S meets the flat sheet took about 30s. Is this normal?

My machine is not fast by any means, but it handles a lot of modeling and rendering without any problems.

Anyway, any comments, observations would be welcomed :)