Talk to me about OD threads

[superman]

Working on a part and struggling to get cocker threads to come out functional. Threads appear to be too big. trying to figure out how to offset the threads to bring them down to size, but i feel like i am missing something. I am using fusion and the prusa slicer.

Thanks.

[XEMON]

The only thing I've found for "precision" threads on 3D print is to make them a hair large and run a die through them ...
It usually quite a bit of trial and error to get them close that the die just run over and clean up the print.

"Precision" is in " " because 3D print will only get so much "Precision" ...

[Siress]

I wouldn't recommend 3d printing threads... period. The stresses involved are not forgiving on discontinuous surface features. When it's necessary, XEMON nailed it. Better, though, is if you can 3d print features that interface with a threaded metal insert. That's going to be tough for a cocker barrel though.

[Rainmaker]

I downloaded JonM's 8" cocker freak barrel from thingiverse, and every time I want to CAD a barrel, I chop the threaded part of his .stl and merge it with my design in Fusion. Whatever he did dimension-wise modeling that, it's always printed well and fit perfect for me. Also, having a freak insert in there also adds rigidity.

[grendal50]

I undersize them by 0.2mm or .008" and they usually work well for me.

[Bulldogr6]

I have only used the ISO thread generator in TinkerCAD but with good success. Decrease thread diameter and scale a bit almost a cue to adding some draft angle I guess.

[MuddyBloodyFactory]

Now someone explain to me how to print smart parts GOG enmey barrel threads.

[Spider!]

Sorry, I can't even remember if enmy threads are metric.

I wanted to add that prusa and super slicer have X-Y compensation and inner and outer diameter compensation settings. Once I got mine set on my old printer, my separate parts fit much better, including threads. I think I had to shrink about 0.3 mm. This was an offset I found by printing different size calibration cubes, where the offset was the same between the cubes.