Making a Mascot

For our recent 3d printing workshop, I prepared a model of DevLab’s unofficial mascot, Dev.

I used Blender to combine a few files I found online: one of a mad scientist sort of character (I think it was supposed to be Dr. Frankenstein), the head from a devil/demon of some kind, and a tail from another similar creature.

I usually use Tinkercad for this sort of thing, since it’s simpler, but in this case one of the files was too big for Tinkercad to handle. I’m less familiar with Blender, so I used Tinkercad to cut out bits from the smaller files and overlaid them together in Blender.

Once I had my exported STL file, I brought it along to DevLab and loaded it into Cura. I decided to make the model about 2.5 inches tall (Cura uses millimeters, so that ended up being 65mm).

Here’s where the trial and error begins. The first few builds didn’t adhere to the build plate, so we tried adding a little glue stick. This worked for a while, but partway through the build the model eventually detached from the build plate. We retried the build a few times but it wouldn’t even stick at the start of the build.

We solved the problem (and successfully printed Dev) by adjusting two settings in Cura: bed temperature and (probably more importantly) the type of build plate adhesion used.

The build plate temperature can be up to 70 degrees Celsius. The hotter it is, the more it melts the plastic touching it, which should help it stick. We bumped this up from the default of 60 all the way to 70.

Cura’s default build plate adhesion method is to create something called a brim. This starts the build by circling around the build area several times to create a sort of extra layer at the bottom (like the brim of a hat) to make the bottom of the build touch the plate in more places. This can work, but I find it usually isn’t the best option since it relies on a very thin strand to stick to the build plate as the nozzle circles around and around. We changed this setting from “brim” to “raft.” A raft creates a full “object” on the build plate, several layers thick, before beginning to print the model on top of that. The raft is laid down much more methodically and is much more stable than a brim. It does take a little longer, but since it makes the build actually work, it’s worth it.

Once the build was complete, removing the raft and supports was a bit of a challenge, which happens sometimes with lots of overhangs. In this case, the arms and tail created a fairly intricate support structure, and in the process of trying to remove it, Dev’s legs broke off. Nothing a little superglue can’t fix, and Dev is ready to get to work in the Lab.