Designing a part to be threaded is something we have been doing for a while. This normally isn’t as simple as would be imagined because overhangs and tolerances must always be factored in.
If the angle that the thread is taking is too steep from the part it may require support material. This support material can scar a print enough so that it won’t thread smoothly.
The fact that 3D printing is additive must also always be taken into consideration if parts are to be mated properly. Below are just a couple of the threaded items we have designed.