MakerBot MicroTip: Using the Support Features in Skeinforge’s Raft Tool

Lately, I’ve been experimenting with Skeinforge 35’s Support preferences (located in the Raft tool) to print objects that either have nasty overhangs (so would be likely to drop loops) or do not offer an easy flat sides to print from. In the past, these tools worked, but lead to uneven results. But with the latest toolheads offering stepper driven extrusion and really precise temperature management, bridging and printing with support structure gets better every day.

One consequence of the mechanical and software engineering updates to the Thing-O-Matic printer: with each new round of releases it is worth the effort to experiment with tuning Skeinforge settings in the Raft tool so that you can see how your MakerBot responds to the new possibilities.

Here are the models I use for support testing:

  • Wizzard by guru (the hat, sleeves, and arms are excellent support tests)
  • a 40% scale, upside down Stanford Bunny (printing inverted will make it obvious if your settings are skewing your model)

I also have a really challenging support test (featured above): animator Raedia Albinson‘s abstract sculpture “SisterRaeSpiral3.” I can’t make this STL available (though she is considering sharing it with Thingiverse) but suffice it to say that this is a cluster of nested spiral tendrils with no flat base. Pretty much the most brutal support test I have found — so I keep threatening the R&D team to send it to them as a test print.1

The Support settings are found within Skeinforge and can be accessed by clicking “Generate Gcode,” choosing a profile from the list, and then hitting the “Edit” button to open up the settings windows.

First Tip: Your settings in the Raft:Interface section will have a tremendous effect on your support material! So that Interface Infill Density (ratio) value determines how dense your support material will be (even though it isn’t in the support material section).

Second Tip: Can you use Support Material in combination with ReplicatorG 25’s Print-O-Matic features? Why, yes you can! Print-O-Matic overwrites some of the values in your profile, but not all of them. So you will be able to get the support material settings you like in your profile, and use a combination of activating “Raft” and picking a “Use support material” setting to use the Skeinforge:Raft settings you have added into your profile.

Here’s a great place to start for settings!

  • Interface infill density (ratio): 0.4 (0.3-0.7)’
  • Interface Layer Thickness over Layer Thickness: 1.2 ( also  0.7)
  • Support Cross Hatch: No.
  • Support Flow Rate over Operating Flow Rate (ratio): 0.7 (0.4-0.7)
  • Support Gap over Perimeter Extrusion Width (ratio): 0.005
  • Support Material Choice: Everywhere
  • Support Minimum Angle (degrees): 35.0
  1. And they keep saying “Bring it on!” []