I have a weird problem with this model I have tried slicing it twice now to see I messed up something in the settings and they both have the M3 screw holes on the model seem be very loose each time. My printer is the Mk3s with MMU2s and I used the Prusa Slicer 2.0 to slice each time. What would be causing this problem?
The lead screw nut doesnt have to be tight. The weight of the Z axis should be holding it down and the screws on the lead screw nut just prevent it from turning. Loose is even preferred because if it’s tightened down and tilted a bit, it can bind on the lead screw. Better if it floats slightly like a universal joint.
The problem is more the screws don’t have any plastic to thread into so they very loose and able to pull out with any slight pressure to threaded rod.
No Idea what caused your printing problem since I don’t see any picture, but if the issue is just the m3 holes then you could either:
-use some longer wooden screws to bite into the plastic
-drill the nut to a larger size, to fit M4 screws
-Melt some plastic into the holes with a hot screwdriver to add a bit of material
-Install threaded inserts by heating them and inserting them in the holes (needs to be pre drilled a bit larger though)
-Heat the nut and put it in place while applying some pressure, it will melt the plastic and get stuck
-Glue the nut in place
-Any other solution you can think of.
Just be creative
You can do a printer calibration test, and check your slicer for things like size compensation. I was sure these were mostly gone but they used to exist for this very reason.
By chance what is the dimension you put in for the M3 holes on the model?
3mm, printer do this undersized by just enough to thread well.