So for easier printing and less waste of filament, I split a model into 3 parts and I want to glue them. Should I add an offset of -0.1 or -0.2 to the surface that I will glue the other part to?
If they fit perfectly without glue and you still wish to use glue, a thin layer of glue in selective spots shouldn’t require additional tolerances.
If your glue is thick and you plan on soaking the plug and socket parts, experiment with tolerances.
Personally, I prefer to design a snug fit where glue isn’t required, but that depends on the model, size, weight and stresses.
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Thank you. It’s these two parts.
I added a protrusion for the parts to not move in the z axis when connected.
May I ask why you needed to separate these two parts? They would have printed fine together by the looks of it.
The one on the right has another part higher up that needs support and there are two of them. So I thought I could flip them and print them separately so they can print with much less support. Also I can’t flip the left part because it has a hole at the top so I would have to fill the inside shelled part with support.
You may wish to keep these together and deal with the part above as a separate part.
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The problem you’re going to have is that the two printed surfaces aren’t going to mate perfectly. If printed with the mating faces on the build plate, there are going to be small irregularities in the build plate height. If printed with those faces facing up, top surfaces are never perfectly smooth.
Also, the two pieces are very different “densities”, they won’t cool at the same rate. They might be printed perfectly by the printer, but when they cool off they may not be perfectly matched anymore.
Not to mention the possibility of slight warping.
If you need a clean/precise fit, I don’t think you’re going to get it.
I make a lot of functional parts. When I need a 3D print to be precise, I print it oversize and take it down to the tolerance I want with my CNC.
I’d leave the part whole and print it 180º from as pictured. Tapered end up instead of down. You’ve got an internal overhang when you do that, but tree supports should be able to handle it fine and they won’t be a problem to remove…
I wish I could see the whole part in 3D. It looks to me like maybe you could print the external shell with a “bore hole” (constant diameter cylinder) down the center, and print the internal shape as a plug that gets inserted in to that hole. No external seams. You can print the two parts with different/optimal orientations and glue the plug in to the external body. Does that make sense?
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