I have a makerbot, and am using their slicer program. The part I am printing has an extremely coarse thread, 5 threads per inch with a 2 mm thread height. The thread face is at a 30 degree angle (15 degrees of overhang)

I have printed external threads like this without issue and without support material before for various gardening tools (a flow straightener for example). I'm now trying to print an internal threaded part however the rest of the part needs to have support. I've played with the settings in the makerbot software but can't find a combination that will acomplish my goal.

I'm looking for an idea, a setting, or an alternate way of printing the threads without support, but still have supports for the other sections of the part that I know do need them.

Perhaps there is an alternate software that can do something like this, or is best practice to modify the part to have weak structural elements to support the extremely overhanging sections that I'll then break off afterwards and print the part with no supports?

  • $\begingroup$ Have you experienced a failure in attempting to print this part? Are the portions of the part which require support in such a position that the supports interfere with the threads which do not require support? Knowing the locations of the threads with reference to the supports would be useful. I'm tossing an answer in the system just in case you find it of value. $\endgroup$
    – fred_dot_u
    Mar 26, 2017 at 17:39
  • $\begingroup$ Given a nut + threaded bolt is one of the demo calibration parts on the printer. Can you include a pic? That said. Either you do air only, or you don't print it. Unless you have the other makerbot that has duel extrusions then you can do a support material.. Or you buy a copy of simplify 3d.. Their supports are smarter and easier to remove. $\endgroup$
    – StarWind0
    Mar 27, 2017 at 22:15

4 Answers 4


There are some software tools that let you manually design support structures so you can target the areas that need them, and avoid others.

For example, Meshmixer can be used to add supports into your STL. I believe you still use a separate slicer.

Some slicers also have the ability to manually add support. I have found that CraftWare and Simplify3D have this kind of feature.

  • $\begingroup$ I'm still playing with MeshMixer, but that's looking like the best solution to the generic problem I was having. The solution I ended up using was "learn the makerware software better". I'm marking this as correct as given the problem constraints I set out, this solution would solve the problem. $\endgroup$
    – Diesel
    Apr 1, 2017 at 19:46

Consider to create an externally threaded part to mate with the internally threaded part, perhaps with a tenth of a millimeter clearance. If possible, configure that part to have minimal structure, making it easier to break away. The externally threaded part will possibly provide support for the portions of the main body while preventing interference with the internally threaded part.

I believe it's not possible to segment a multi-part print for different levels of infill, but if the above fits your requirements, it would be a thin-wall cylinder, thick enough only to support the mating threads. This would allow easier break-away.

An image, sketch, drawing, model, link of your project would make this answer easier or possibly invalidate it completely.

  • $\begingroup$ It might be possible to have two overlapping models taking different print parameters. Doesn't strike me as a good choice though. $\endgroup$ Mar 27, 2017 at 10:38

I feel a little ridiculous that I didn't try this earlier, but in the Makerware software you can set a minimum overhang to print support material. I've been working to this point (3 years now) assuming they've been measuring the angle from the vertical, not the horizontal. I was wrong.

The solution that I came up with was to calculate the maximum overhang of the internal threads inside the helix, and then not use breakaway support below that angle.

Not the prettiest print I've ever done, but the threads came out useful at least. I'll need to lay with the settings a bit to make sure the part isn't going wonky from the minimal support but as of now it seems to be working well.

A better slicer would've made this whole process MUCH easier, and I'm going to look into them pronto


Try using simplify 3d. It's a very powerful slicing software compatible with almost every 3d printer. It does cost 150 dollars, but that would be the only drawback to using that software. You can manually place supports around your model without having he software mess it up. I think this is exactly what you're looking for.


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