Notifications
Clear all

Tree supports causing gap to sharp vertices  

  RSS
wes.w2
(@wes-w2)
Eminent Member
Tree supports causing gap to sharp vertices

I have a model that in mesh mixer I am building tree supports. In meshmixer and slic3r prusa edition the tree supports look connected, but the vertices of what they are supporting are so sharp and pointy that when slicing occurs it results in 3-6 layer gaps between the support tip and the sharp pointy tip being supported.

I suspect that I need to blunt sharp points somehow in meshmixer in order ot make this work, but I don't entirely understand how I can globally take something in meshmixer and say "please cut off any point ends and round them out so that they are at least .15 mm in size at the tip" or something like that.

Any pointers?

Posted : 03/01/2019 3:27 am
wes.w2
(@wes-w2)
Eminent Member
Topic starter answered:
Re: Tree supports causing gap to sharp vertices

After doing some slicing in other software packages, I get the same results... the slicing process causes there to be a gap between the tree tip and the very sharp narrow tip of the model. It is definitely an issue I need to address in my STL - by shaving off parts that are too pointy to slice with a .25 mm nozzle (they are so small they just get dropped) --- then build my support trees --- anyone have a good link of how to do this with an algorithmic in mesh mixer?

Posted : 03/01/2019 4:09 pm
thrawn86
(@thrawn86)
Honorable Member
Re: Tree supports causing gap to sharp vertices

if you can share the model and some pictures that would be helpful

Posted : 03/01/2019 10:40 pm
wes.w2
(@wes-w2)
Eminent Member
Topic starter answered:
Re: Tree supports causing gap to sharp vertices

The model is this:

https://www.thingiverse.com/thing:3247595

When slicer slices the tree supports to the sharp pointy fingers, even through they look connected in meshmizer, you lost 5 to 8 layers of air between them because the tips are too small to render into a layer so they just get dropped.

Posted : 03/01/2019 11:03 pm
wes.w2
(@wes-w2)
Eminent Member
Topic starter answered:
Re: Tree supports causing gap to sharp vertices

Ok -- I have made some progress --- I went to meshmixer and did a "thickness" analysis on the model and had it flag everything in red that was < 0.25mm (my nozzle size)

I then selected the parts that I have had some trouble with, and hit edit -> extrude -- and thickened to .25mm

Then I ran a make-solid to turn it into a horribly oversized STL file.

I loaded that in Slic3r PE --- used my modified .05 mm layer profile and did one further tweak... I set outer perimeter width to .20mm (The insanity!!!)

I then was able to get a slice where my tree supports had no more than a 0.05mm single layer gap. This was working great, until one of my supports snapped under the stress and I created spaghetti on one side of the model and had to stop it.

I will redo this in a couple days when I have 11 hours to retry the job with a thicker tree support and an extra strut right above where it snapped.

I am close.

Posted : 07/01/2019 9:04 pm
JoanTabb
(@joantabb)
Veteran Member Moderator
Re: Tree supports causing gap to sharp vertices

do the extra strut, below where the previous one snapped, to give stability...

the previous failure was probably preceded by a period of support wobbling, before it actually snapped, you ideally want to prevent this happening!

regards Joan

I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK

Posted : 08/01/2019 2:50 am
Share: