Tapping into 3D Printed Parts

[Aaron Ng]

Originally Posted by Chak

Someone on my team did that, except he also pointed a heat gun at the 3D printed part before he forced the screw on to soften it around the screw. It worked, but then again he was just making a mount for a computer fan and so didn't need much strength.

bit of a correction: I heated up the bolt only, and with a hot bolt, threaded the plastic. Pointing a heat-gun at the piece would have probably killed it

The threads are clean, and I would think that this is the strongest way to tap a piece of plastic, but that's just my gut feeling.

Of course, it also depends on how deep the threading is, and the bolt size. But like others have recommended, putting a nut on the other end would make a undoubtedly stronger product then my method.

[Justin Ridley]

It's been mentioned a few times already but I'll reiterate that heat-set inserts are the way to go.
This is what we use:
http://www.mcmaster.com/#heat-inserts/=10w65lb

We've used self tapping inserts for plastic as well, however, a printing lab at JSC recently did a pull out study testing different inserts in different 3D plastics and they found the heat-sets performed best.

They're inexpensive and easy to install with a soldering iron. Just file away any melted plastic that raises above the surface.

[cadandcookies]

While there's a lot of fantastic advice on here about how to do this right, in a pinch and when the forces are in the right directions, you can get away with threading directly into a piece of plastic. As an example, we used 100% fill ABS printed pieces as clevises (clevii?) on the 'Snow Problem catapult. Here's an imgur album with pictures of the implementation. Personally, I wouldn't recommend it, and I'm somewhat surprised they've held up for the couple hundred shots we've taken with Perses, but in this particular use case, it worked out to thread directly into the plastic.

[Matt_Boehm_329]

I actually do this a lot at work for lower load applications. Most bolts can self tap the hole in the plastic if you print the correct size hole and use a higher shell count. (Even the end of a pneumatic) Speaking from experience, if you are going with ABS, PLA, or PET, I would recommend a higher infill than 5% as in one of our experiments it wasn't the hole or threads that failed but the infill. I haven't done extensive testing but using that sort of force you are probably looking at >=25% infill around the threads and a few layers below the bottom of the hole (if the threads don't pass all the way through the part) and the parts would still be considered consumable. (My work printer is .2mm layer height)

[Munchskull]

What I have always done is print the hole slightly undersized the for the bolt then I force the threads in with the bolt. Works well for non-load bearing part if printed with PTE. Not sure about PLA or ABS.