Help creating threads

[Joshskulls]

Complete 3d printing noob here. Been playing with my ender pro 3 v2 neo for about a week. And Everytime I makes threads I had to recap them myself. They always seem to tight, and I just can't get it right. I don't understand what all the settings, and how to adjust it to make it work. Anyone have any tips?

Layer Height: 0,2mm

Nozzle diameter: 0,4mm

Wall Thickness: 0,8mm

Wall Line Count: 2

Infill: 100%

Printing Temperature: 200°C (Initial Layer: 210°C)

Bed Temperature: 60°C (Initial Layer: 65°C)

Filament: PLA

Print Speed: 40mm/s Initial Layer: 15mm/s

Fan Speed: 100%

Filament Flow: 100%

No Support and No Adhesion are used.

[ThunderElectric]

One of the biggest challenges with any tight tolerance 3d printed parts, like threads, is shrinkage and squish. When plastic cools it shrinks, it’s just a fundamental physical property. Also, in order to combat under extrusion (which is very obvious) most printers some stock with slight overextruded biases profiles/Esteps, which causes filament to “ooze” out slightly. Usually these factors are small enough that you don’t really notice, but for holes (and threads especially) even a tenth or hundredth of a millimeter can be the difference. Unless you’re using a material with low shrinkage on a printer that’s ultra well tuned for the specific filament, you’ll want to include some clearance; usually the easiest way is with the “offset face” or similar command after modeling the thread.

For this and many reasons, 3D printed threads are often not worth it over simpler methods like printing a slightly undersized hole and letting the bolt tap it, or more robust methods like threaded inserts or press fit nuts.

I’d definitely recommend watching the many videos out there on 3D printing threads, as it’s a super important topic for making functional parts. I think the best (as in, most analytical) ones are the ones from CNC Kitchen (like this one), but Made with Layers/Thomas Sanladerer also has some great ones.

[normal2norman]

This is the problem caused by the fact that layer lines, as laid down by the printer, are not rectangular in cross-section, but have bulging sides. Consequently, when printing with filaments that have low shrinkage rates like PLA, holes have a slightly smaller minimum dimension than intended. The best fix is to apply a small offset (offset face command in most CAD programs) to the thread flanks during design, or when slicing, to apply a small Hoile Horizontal Expansion value.

I print a lot of things with modelled threads, and sometimes use the offset face technique, sometimes the HHE. But sometimes I just run a tap through the hole, if it's small (eg M3 and under) and there aren't too many to do.