Slic3r Support Material Settings?

I’ve just started to use support material with ABS on a print and it seems to be very hard to remove afterwards when using the default Slic3r support material settings. The print is fairly small (2" x 2" x 1") and has 1 large overhang that requires support underneath.

Can anyone suggest Slic3r settings that may work better than the default? Also, the Slic3r manual doesn’t really provide any guidance or descriptions for the what each of the settings are meant to do. Any help would be appreciated!!


Change your pattern spacing to 4 or 5mm. You may want to try Slic3r 0.9.10b as support is much easier to remove in that version. I can brush the support structures right off with very little effort.

Can you post the .stl, or a link to it?

Here is my understanding of the settings and what they do:

Generate support material turns support on or off.

Overhang threshold sets the angle (measured from horizontal to the tangent to the surface) below which support material will be generated. For example, if you are printing a sphere and you set the overhang threshold to 5 degrees, then slic3r will generate a relatively small circle of support material – in the plane of the layer – directly beneath the sphere. As you increase the Overhang threshold, slic3r will generate increasingly larger circles of support material until you reach 90 degrees, at which point the diameter of the circle of support is the same as the diameter of the sphere.

Enforce support for the first n layers will allow you to generate support only below a certain z height. To find how many layers to enforce support for, decide how high you want support to go, and then divide by your layer height. If enforce support is on, support will be generated for those layers even if the Generate support material checkbox is turned off.

Raft layers are additional layers of material that will print underneath any model or support material. They are about .5 density and resemble infill.

Slic3r generates both non-interface and interface support material. If the support material touches the model, then it is interface support material. In the Options for support material and raft, Pattern, Pattern spacing, and Pattern angle all refer to the non-interface support material.

Pattern is just like infill pattern, but for the support material. This setting determines what geometry the supports will be.

Pattern spacing is like infill density, but instead of being an index, where 0 is hollow and 1 is solid, Pattern spacing determines how far apart the support structures will be in units of mm.

Pattern angle sets the angle, measured from the x-axis (i think) at which the non-interface supports are printed.

Interface layers sets the number of layers that print in between the non-interface support and the model. These are preferably set to a much denser pattern than the non-interface layers so that you can both maximize the surface area of the support in contact with the model to prevent sagging, while minimizing print time and material use with a bigger non-interface pattern spacing.

Interface pattern spacing this is just like pattern spacing, but for interface layers instead of non-interface layers

Again, this is just my understanding of the settings. I recommend trying a few configurations, and then using a gcode previewer like to check the tool path layer by layer.


I second support being easier to remove in the older version. The new version everything sticks to the part.

Kent - thanks for the great descriptions for the support settings. This really helps! I tried to upload the stl file, but it was too big. I’ve attached a picture of it, though…a classic chess piece knight.

Thanks to others as well for the recommendation of reverting back to the older version of Slic3r. Who would have thought that the latest versions aren’t the best? :laughing:

Thanks, Ross

The image on the left is the knight print with support material turned on in the latest Version 1.0.0RC2 with the default settings. Needless to say that removing the support material is impossible.

The image on the right is the knight printed in 2 halves with the cut section laying flat on the heated bed, then gluing them together. It was then dipped in a heated acetone “steambath” for about 15 min.

Printed in ABS with a 0.50" nozzle.


Have you heard of Meshmixer by Autodesk? It’s a mesh editing program that in its latest version can generate scaffold-type support structure. I think that’s the way the slicers will have to go to make support easier to remove.

It’s free and available on Windows and Mac OS X. Nothing for us Linux geeks…

What has been your experience with Meshmixer? Is it pretty easy to remove? I wasn’t able to listen the video with sound but some of those connections look pretty thick and and I would be concerned about my nozzle knocking over those support pieces.

For items needing support, I use Slic3r version 0.9.10b as it’s worked out the best in terms of support material removal. I will usually have the overhang angle set to 0, and the patter spacing set at 4mm.

As I said I am a Linux user so I cannot use Meshmixer.

Awesome, thanks! Now I know what I am going to do today… :smiley: