Parts require excessive force during assembly, is it a tolerance issues?

[maedmatt]

I'm having troubles assembling the 3D printed parts and would appreciate some help. This is my first time 3D printing, so I may be missing something obvious.

I'm using an Anycubic Kobra S1 Combo with PLA+ material from Anycubic. The overall print quality appears good, but all the connection points require excessive force to assemble, whether I'm connecting parts together or attaching motors. There seems to be very little tolerance, making assembly much more difficult than what I've seen in online.

I've experimented with adjusting various print settings and done multiple test prints, but the fit issues persist. Are there recommended tolerance adjustments for this printer and material combination? Should I be scaling certain parts slightly to improve fit? Are there specific slicer settings that typically help with part tolerances?

Any advice would be greatly appreciated!

[dmosher42]

This can occur due to material expansion and a few other factors.

If you want to reprint it, see if your slicer has a setting like XY size compensation (PrusaSlicer) or hole horizontal expansion (Cura). You could also try turning on Small Area Flow Compensation to avoid over extrusion that could lead to holes getting smaller.

Make sure your filament is dry. Remember that some filament manufacturing processes introduce water to the filament to cool it.

I suggest doing some test prints first to make sure your prints are dimensionally accurate while wasting less material. You should be able to do this by using the cut tool that is included in most modern slicers. EDIT: Alternatively, use the gauges. Using those should be the best for minimizing materials while testing tolerances.

If you want to use the parts you have right now; for screw holes you can heat up the screws. For other parts you can maybe use a heat gun to soften the material. I would not suggest using the heat gun on the servos or other electronic components. There is a high chance of burning yourself or ruining the part, so I'm not sure I would recommend this.

~~There should really be some dimensional print tests included in this repo. I may work on that once I get the motors for my arm.~~ Use the gauge tests.

[cnapole]

I tried yesterday with the gauge tests (check around the printing section) with a k1c. I've dealt a bit with the motors until I got a configuration of 0.3mm layer height and a std quality config in Cura.