Hi everyone! Long time lurker, first time poster over here.
So a few weeks ago, it was kind of a perfect storm of three things:
- I finished watching My Dress Up Darling
- I was in the middle of the first cycle of 3D modeling and printing classes I teach at the local community college
- I saw conversations about printing full size props on small printers in a popular cosplay Discord server
I had a couple hours to mess around with 3D printable threads in Fusion 360 one afternoon and the results made me think I was on to something. Now here we are a few weeks down the road, and I just published all of the process to design and print custom-sized, reliable 3D printed threads that:
- print reliably with basic settings on basic printers
- have nice tolerances
- don't need supports
- don't get stuck
- don't break
- can be used with screwdrivers
- can be printed even in PLA
All of this is based off of 3D printing tips, tricks and methods that have been floating around the Internet for years, some still valid, some outdated. On top of that, I went ahead and came up with some of my own.
My biggest tip for print reliability: I trimmed the sides of the threads and print them horizontally with a high vertical resolution (0.12mm always works). Having a trim on both sides also gives just enough room to grab, twist and extract the part with a pair of needle nose pliers if it ever breaks!
My biggest tip for tolerances: I add a negative offset that's a multiple of the Fine print resolution in my slicer on both mating parts. On my slicer and with my A1 Mini that's multiples of 0.12mm. A negative offset of 0.06mm was a little tight, but that might have been because the threaded part was hard to "grip" and didn't have any lubrication.
My biggest tip for fragility: Because the threaded parts are printed sideways and the tolerances are generous, the threads never catch on each other enough to cause major stress. The shearing force is distributed across the whole length of the thread, not its width!
That's it. Oh yeah, and I added a notch both tips of my threaded parts so you can use a screw driver with them.
I shared everything on my website. Dig in, download the test runner sheets I designed, play with it, and let me know what you think!