Tuning flsun prusa i3

Hi!
I am really happy with my flsun prusa i3 now, except that it is not 100% accurate when printing things that should fit together like a threaded bolt and a nut, they look really nice but just dont fit together.
How do I tune this?

My radial fan sounds really bad to. Have ordered a new one, it sounds like it is screaming or something. I am thinking of taking it apart and clean it...

Not knowing where you got the model from, I would be inclined to think it was badly designed

ie hole diameter of X and the thread is X wide.. where as the hole needs to be X+0.15 or the thread needs to be X-0.15

It was this knurling bolt and nut from thingiverse:
[www.thingiverse.com]

I tried with another smaller m3 bolt and nut and got the same result.

Found this answer in the comments field on thingiverse:
Oops, I misunderstood your comment.
I think the extrusion rates of filament on your 3dprinter is little big. So the extruded filament from a nozzle is more fat than the nozzle diameter. As a result, the bolt is slightly too large and the hole of nut is slightly too small.
Please check and calibrate about your 3dprinter, one is a feedrate of steppermotor for extruder on your firmware, another is a extrution multiplier of your slicer.
Thanks.

I think this is the problem, because I have changed the extrusion multiplier to a trial and error number, I have increased it a lot, when I tried to measure and calculate I didnt get the right number...

Edited 1 time(s). Last edit at 06/11/2017 05:15AM by affa.

I had the same issue with the same file.
I think I printed the nut 3-4% bigger to make it fit.
PLA might be ok but with my ABS it didnt fit worth beans.