PLA support surface quality issue  

RE: PLA support surface quality issue

Supported surfaces are always going to be ugly when using removable supports. You can improve results slightly, but the very nature of removable supports requires compromises. For the supports to be removable, there has to be a small gap between the supports and supported surfaces. This means that the layers printed immediately above supports are literally printed on air. Extrusions will be rounded due to lack of underlying layer squish, and may sag a bit.

You can improve appearance somewhat with settings, but don't expect miracles. Other slicers handle supports differently and perhaps better for your needs. Your best options are:

1. Orient the part to minimize the requirement for supports.
2. If designing the part yourself, consider support limitations and minimize the need for, or include supports.
3. Break the part into multiple parts that can be printed without supports and assembled after printing.

Maker's Muse has a very good YouTube tutorial on this topic. 

RE: PLA support surface quality issue

Here's an example of the same part printed using different slicers to support the big square surface. Results are left-to-right, top-to-bottom: ideaMaker, Simplify 3D, PrusaSlicer, Cura.

RE: PLA support surface quality issue

Hi Bobstro,

Many thanks for your quick response. I will try to optimise the design and also will try a different slicer.

Cheers,
Marc

RE: PLA support surface quality issue

@bobstro

Prusaslicer comes out a distant last. Does anyone know why?

RE: PLA support surface quality issue

Posted by: @john-h68

[...] Prusaslicer comes out a distant last. Does anyone know why?

Best I could understand from the GitHub threads is that it's legacy approach from Slic3r roots. It had some benefits, but other slicers have moved past it apparently.

PrusaSlicer puts a layer of bridge down under the supported surface, and it can't easily be removed. You get that ugly stringy surface and it's thicker than designed. I think the devs are aware of it, but it hasn't bubbled up as a priority yet. 

IdeaMaker is an interesting alternative. I prefer PrusaSlicer, but will use what works. If I can't avoid big supports, try the others. None are exactly pretty.

RE: PLA support surface quality issue

If you take a look at the Cura documentation, the options for supports are literally overwhelming!

I've only scratched the surface, either with Cura or Prusaslicer.

One of the best things, however, in learning how to do supports that work acceptably and come off reasonably well is the set of parameters that's floating around here on the forum.

RE: PLA support surface quality issue

I'm getting good results using PrusaSlicer for things like miniatures. Large flat surfaces are a problem, and it seems to be that bridging layer.