Making shoe mold

Hi Everyone,

At the moment I’m doing an experiment for a shoe mold for a kind of ‘injection molding’ for a school project. I already modelled the last and the piece where I wanted to make the mold from.

Here you can see the parts of the upper part of the mold. (There also is a bottom part, not seen here). The whole upper is a solid object. To make the mold I would like to subtract this part from the extrusion (block) for the pouring mold. I want it to be a solid object to eventually 3d print the mold.

I already tried to use the boulean difference command, but then I got the following outcome.

Can anybody solve this problem or have soms tips/help?

LAST MOLD v5.3dm (2.9 MB)


Please upload the .3dm, images are ok but you will get best assistance with a 3d file.

When you do a showedges command with the shoe highlighted, does it report any naked edges or manifold?

You could also try shifting the shoe up a bit so the top flat surface is not at the surface of the box or too close to it when doing boolean.
Or could be bottom surface.

Trying boolean with another object may help identify the issue.

Hi Vladimir,

Ah okay, kind of new here.

Just uploaded the .3dm files of the whole mold. (incl. the bottom part)

Hopefully it will work better now. Thanks.

issue is:

  1. The shoe is not a solid, pick the bottom row of points(for the shoe) - setpt - z axis and click below the box, maybe 2 or 3 mm for tolerance, then type “cap”

then booleandifference them.

attached is the fix.

fix.3dm (9.0 MB)

Ah it indeed had a naked edge on the bottom. The ‘Join Edge’ command solved that part I guess.

Thanks a lot! The fix.3dm is exactly what I need. I tried to fix it myself but then I also came across some problems.

Bit newbie, but what do you mean with:


With the cap command I often get the error “unable to cap one object. The openings did not have planar loops of edges”. Also in this case when I did the command. How did you prevent this?

When you press f10 while having a surface selected you will see the points that define the surface. (shoe in your case)

  • pick any point in the lowest row (where the sole would be)
    -type sel u or sel v depending on the uv coordinates for that surface
    -once the whole bottom row is selected type setpt and select z axis
    -click 2mm below the box

It’s just a fast way to planarize so you don’t get errors when you type “cap”

Ah I see, in my second try it did work out and now I sort of get it. Thanks a lot for your help! Cheers.