layershift when printing small miniatures' legs

[ultradryan 9]

 

 

I am printing somefairly small miniatures and their legs always give me headache for printing.

The above image shows the layer shift on the legs.

 

 I am using UM3 with PLA, most of the time my prints are fine but when it comes to small things and structure like this it seemed to fail.

The adhesion is okay, but after a while the nozzle started to sort of knock the legs around a bit causing a layer shift during print.

 

I have been printing slow at 30mm/s.

I have checked the belt and they are tight.

I have done manual leveling on buildplate just in case.

Switching materials(brands) doesn't seem to hv differences, and this is some good eSun filament.

 

none of the above action help.

So I am going to show you how i slice my STL, see if i done sth wrong there.

 

 

 

I have tried different ways and both still have layer shift issues.

The first one with support interface enabled, support enabled, support brim enabled, tree support enabled, and increased 40% support density.

The nozzle would knock on the printed legs and cause layershift mid-way, usually on one of the legs.

The second one is on same settings but with a manually added cube printed as support.

This one has less major layershifts but lot of minor shifting along the print, the result is shown in the first photo.

 

Any good advice?

 

[geert_2 557]

Have you tried designing a custom brim in the CAD file itself, and maybe some sort of tree-like or inverse-tree supports? Just to add more stability? I guess it now starts wobbling around due to the brim or supports not being stiff enough?

 

An added issue could be not enough cooling, due to the hot nozzle sitting continuously on a small area, which tends to increase this sort of effects. So, adding a dummy cooling tower or printing multiple at once might improve this. But it might also worsen the situation if during traveling around, the nozzle would hit the legs...

 

[gr5 2,094]

I don't see the layer shift.  The legs seem to match the view from cura.  Can you point an arrow very accurately to exactly the problem spot?

 

 

[ultradryan 9]

printing even slower simply soft the problem, i lower it down to 20mm/s and the shifting is gone.

[gr5 2,094]

I still don't know what you are talking about.  Can you show one with "shifting" and one without?  Usually when people talk about shifting it's a problem where a stepper misses a step and the entire part shifts to a new X or Y location such that the bottom half doesn't line up with the top half.  LIke this:

 

https://support.3dverkstan.se/article/23-a-visual-ultimaker-troubleshooting-guide#shifted

 

[ultradryan 9]

i have thrown away some more obviously layer shifted ones. but in the photo  there's a layer where up to a point the print  shifted a bit to the right. this usually happens when printing two-leged models from bottom up, perhaps somehow the nozzle knocked the print a bit and the two towers doesnt match up at some point and show shifting. Printing slower somehow prevent this from happening