Screw 3D Prints
What is the best way to screw 3D printed parts together? I've seen a few approaches :
- Threaded metal inserts which are melted into the part after printing.
- Machine screws directly into the part (cutting its own thread, or using a tap if you have one).
- Self tapping screws into an undersized hole
- Captured nuts.
I started using a different technique, which seems really obvious when you hear it, but I've never seen anybody use it,or test how well it works...
Wood screws into 3d printed threaded holes of the correct pitch.
Here's my logic. We want the functionality of machine screws, but the threads are too small, and the tolerances too tight. But if we chose screws with large threads and large pitch, then we CAN print the screws threads into our parts. Wood screws have large threads and large pitch!
A small downside to using wood screws is the tapered point - this part of the screw will do nothing for us. Our hole will have to be longer than strictly needed. Or buy "self tapping" screws (with a blunt end). Note we aren't using their self-tapping nature - we still print the hole pre-threaded!
Ironically, days after I started using wood screws I found this YouTube video : Well, it turns out you CAN use screws in 3D Prints!. I thought they had discovered the same idea simultaneously. Nope, he is printing cylindrical holes and tapping the hole with the screw.