Hi TuttleJA, good morning to the Community!TuttleJA wrote: ↑Mon Aug 30, 2021 9:01 pm Hi domad, That's very nice... Maybe some day I'll learn how to add color... Right now, what I need is a negative mirror image so I can 3-d print a mold of the part. Then I plan to use the mold to make rubber parts that look identical to the part you made solid and colorful. Using Boolean, I think I was able to made the part solid and then get the negative/mirror effect, but it's on the wrong side of the mat.
When you have the solid (!) "Positive" (punch) available, obtaining the "negative" (matrix) is very simple, using any 3D cad, even more so with FreeCad, just apply the boolean function difference between a parallelepiped (a little more large of the "postivo") and the positive itself.
Since the "negative" (matrix) you will use as a mold, one thing to consider is extracting the printed body from the "negative" (matrix). I recommend to slightly incline all the side faces in order to facilitate the draft and to connect all the straight edges. But given the small thickness of the molded body and the material it is made of (rubber / caoutchouc) it could work even without these precautions.
Today (weather permitting) I hope to get the "negative" (matrix) and post the result.
The coloring of the faces (it is a very simple thing to obtain in FreeCad with Workbench "Part") was done to highlight the low thickness of the letters, certainly not for aesthetics.