Bad "lines" when print almost horizontal surface on bottom of model
Hello, i would like to ask, if there is any solution for this. I was printing head of a funko-pop figure with 0.2mm layer height with PLA material.
It needed supports at its bottom side. I have used organic supports on build plate in Prusa Slicer. After printing and removing supports, there was plenty of filament "lines" stuck there which can be hardly removed, or cant be removed at all. Its mainly at the very bottom, where angle toward print plate is very sharp and gaps between layers are biggest.
I have cut the original model to made only its bottom portion for testing. I tried Variable Layer Height in Prusa Slicer at those places, setting it to lowest layer height it allowed (0.07mm, green portion of the model) for problematic part of the model, but it went the same. I have to use grid type supports as Prusa Slicer told me that organic supports arent compatible with variable layer height print.
Is there any way to improve or solve this and print that portion of the model nicely round? Thanks
.
Two main choices -
Invert the model so the curve is on top.
Replace the curve or fillet, with a 45° chamfer.
Cheerio,
RE: Bad "lines" when print almost horizontal surface on bottom of model
Its a model of head of a figure, so inverting it in any direction would only move problem to other part of it. The problem is at its chin and entire bottom area. It looks like this:
RE: Bad "lines" when print almost horizontal surface on bottom of model
No there is no way in that orientation. A curve like that is almost a complete overhang at the bottom, there is not enough room under the part to fit support as well as leave the required support gap so no matter what types of supports you use it wont help. Curves like that are not designed with 3d printing on FFF in mind.
You have several options. Print on a multi layer raft of soluble support if you have a multi extruder setup or are willing to do the many manual changes without (not what I would recommend).
You could split the part so there are flat surfaces with the curves oriented up. Add locating holes and dowels using the Cut tools built in options to aid in gluing together. Which would be my recommended option.
You could raise it up above the platter using various methods (nno printing part on the bed etc) which would mean more room under it for supports. However generally this wont really look nice anyway as anything printed using non soluble supports with a gap wont be smooth.
RE:
I've had success doing curves like that by using a zero support clearance. You'd have to use PETG for the support. Without a MMU this would be tough, but not impossible. Just lots of manual filament changes.
Essentially you'd have to model in CAD the exact reverse image of that curve on your model. Keep it a separate body.
Im not going to list every step here as you can research it
Here's an example where I did the exact the exact same thing. You can see the white ring around the bottom of the part which is PLA supporting the PETG part.
RE: Bad "lines" when print almost horizontal surface on bottom of model
Thanks everyone for advices. Finally, I managed to get most from it by setting Variable Layer height to lowest part of the model, where problem is most visible and manually paint supports. Automatic supports make much more of them, which is problematic.