trenchPhysics | Page 2

Skull shotglass being printed

3D printing with support material increases the kinds of objects you can print. Usually when designing the concern is to print parts without overhangs. This was a problem, so I started experimenting with support material. I’m using Printrun and Slic3r 0.9.8 for printing. The change to get support material is in the configuration file in the standalone version of Slic3r.

Open Slic3r and go to the Print Settings tab. Open the Support material settings. In the Support Material page is a checkbox for “Generate support material”, click it and when you slice now, it will generate it for you. Lets have a look at the settings.

Overhang threshold: Slic3r checks for the overhang angle, if the angle your printing out is higher then this number then it will print support material under it. The default is 0 but should be changed under some situations. Keeping a low support angle isn’t necessary, many printers can print 15-20 degrees without any issues of over hangs. It is beneficial to keep a low support angle if the part your printing is very small, since it will help prevent warping.

Pattern: Rectilinear will give you single extrusion wide walls at the default of 2.5mm spacing. This is convenient because you can pull it all out in one strip.

Pattern: Honeycomb will give you a honey comb pattern. This works better with more organic shapes.

Pattern spacing: Slic3r sets the default at 2.5 mm. Setting the spacing lower is going to use more support material and make it harder to remove afterward. Adjust this if your overhangs are close to 90 degrees and its a small piece.

Pattern angle: Pattern angle adjusts the rotation of the pattern of the support material. Sometimes the pattern will have a flat wall that is close to a wall in your model, making it nearly impossible to remove cleanly. If your slice is having interference issues with your support material then rotate the angle to an angle you likely do not have in your model .

The two models I used are: