Hi,
I’ve got a part here and I’ve set the roof/floor layers and the wall thickness and infill. All good. But I need extra thickness around the screw holes to tap an M6 thread. I don’t want to increase the overall wall thickness. I’m using inventor to design the part and save to STL.
I tried putting an extra cylinder around the holes but looking at the layer slices, I can see the cylinder but it just seems to print as if it’s not there.
Anyone got a solution?
You haven’t stated what slicer you are using.
PrusaSlicer has “modifiers” which you can use to change parameters only within a certain volume.
However, for your use case, be aware of this:
The issue they complain about is closed but not necessarily entirely fixed:
I use two techniques for holes I tap, or use self-tapping screws in.
One is positioning. Placing them so that my slicer treats the space around the hole as being below the ‘solid infill for small areas’ threshold and reinforces the mounting. Or near to other external walls so that the gap is filled.
The other is to use a hexagonal (or pentagonal) hole, with the Outer Diameter set to the clearance diameter of the screw.
This gives a good grip on the screw, without weakening the hole too much even when using the default wall size. I’ve used it several times in both PLA and PETG parts.
For instance; here is a detail from a case I designed:
The hole is 4mm diameter, in the lid piece (cut from acrylic) this is round but in the case itself I use a 4mm hex hole.
Positioned in the corner like this it ends up with quite a bit of reinforcement around it.
and the end result, using some 4mm dome headed screws, is good. And quite strong:
Thanks. Thats a good idea.
