Hello to the Bambu Community, I’m a new member so be gentle.
I’m have issues printing threads on my Bambu X1. Printing the bolt part is fine 50mm diameter but the nut part is causing issues.
It seems that there is a lot of stringing, the parts do screw together after some cleaning up but I don’t want to mess around doing this process
I have attached a photo; I hope to show the issus I’m having.
Thanks in advance
welcome @simon.baker1971, can u share printing profile? this seems to be filament extrusion not stringing, would appreciated screenshot of the preview in the Bambulab Studio
I have printed a lot of threaded models and I have seen this issue many times. The way I was able to prevent this was to round the sharper inner edges of the threads.
The issue seems to be that as it is printing the sharp edges they fail to adhere properly. But if they are rounded, there is more support for the material to build on and the treads still work (in my experience).
Printing threads usually fail because layer height it too much. Sweet spot is 0.16mm or lower. You can add a height range modifier and change that area.
yes indeed, or more rounded or less fo 50° of inclination
There is a setting in the slicer “Avoid Crossing Walls” which may help. What that does is if the head travel would go from one place directly to the next, it is supposed to avoid travel across distances.
Having said, your line movement is a bit perplexing. I can’t determine why there is even cross movement anyway. You might also try changing the print order from the default of inner/outer to outer/inner. This will lay down the outer walls first.
Actually that would likely worsen the issue because “Outer Wall” on a hole is the loop furthest on the inside so it would be missing the anchor of the “Inner Wall” loop if it is printed first.
Have you tried it? My own experience has been that when producing threads in a trouble filament like TPU as an example, I get minimal results from just using either avoid crossing walls or wall order. However, combining the two features together has a very different outcome as opposed to using them individually.
I design and 3d printed a multitude of threaded components for industrial prototyping jigs and where permissible I will change the thread angle for easier printing and/or modify the sharp tips by rounding them ( mentioned by someone else above ), where not permissible, e.g. mating with CNC or conventional machined metal components, a reduced layer height usually does the job for those threads.
Outer wall first in my experience never works well with these partial overhang situations and yes I tried it and for me it never worked to improve threads.
Example of layer height on a 10x0.5mm internal thread.
0.28mm layer height has a lot of overhangs and ends up like what the OP has.
0.16mm layer height no overhangs, finer print.
My first suggestion for people who aren’t happy with the thread output is to use a thinner layer height. The thinner the layer height, the better the performance. Yeah, it sucks for time, but its the most effective change.
I tend to set everything at .20 mm and go back to the sections (like threads) and use the variable layer height function in the slicer. Works like a charm.
If that doesn’t work, its possible your threads are just too steep of an overhang. You can combat that by slowing the print down and/or adding fan, but the limit is the limit.
If the threads are common normal threads, look for other issues in your slicer settings. Sometimes fixing one thing, breaks another.
Question: what is the smallest thread you have been successfully to print? Also include material please.
I’ve successfully printed some really fine thread on my 3d printer
