My first longboard footstop 3D print job is done!

My first printed footstop is a success!

I got an email just after noon today from the Hillsboro Public Library:

Your print job is finished and is waiting for you under your name at the checkout counter. Please let me know if you have any questions. Thanks!

Within an hour, I was holding my first 3D printed object. It’s very light and rigid. And of course, pretty!

I held the footstop up to Jamison’s downhill board to check fit. The slot spacing looks perfect. Jamison’s board has significant concave so I might want to put some flexible material between the board and the middle of the footstop. And the color is a nice match to Jamison’s new Orangatang Kegels. Nice!

I’m amazed how well this turned out. Now to get some longer truck mounting hardware so Jamison can install it and tell me how it works.

3D printing solid parts

This last Monday evening, I went to the Hillsboro Public Library 3D Print Lab to get one of my longboard footstop designs 3D printed. I was concerned my design wouldn’t meet their requirements because I had done nothing to minimize the amount of plastic it would need.

In preparation for the lab, I had downloaded and experimented with Meshmixer, a program for modifying .stl files. Meshmixer can automatically hollow out objects but I didn’t know whether the resulting object could actually be printed. After all, 3D printers can’t print on air; there must be a supporting structure. So I showed up at the lab with my original unmodified .stl file.

At the lab, I learned a few things:

  1. The program that drives the 3D printer is smart enough to create a temporary supporting lattice underneath an otherwise unsupported portion of a printed object. For example, if you want to print a sphere, the program would automatically generate the portion of a cylinder beneath the sphere as a support base. The program generates a weaker connection between the support base and the desired 3D sphere so the base can be removed from the sphere with some effort.
  2. Not all unsupported portions need a support lattice. Objects can expand out at up to 45 degrees before a temporary support structure is needed under the cantilevered portion.
  3. The program is smart enough to automatically hollow out solid objects, defining a minimum wall thickness and then filling the interior with a lattice to support the object’s top surface. The picture at the top of this post shows coarse and fine lattices.

In short, the program that drives the 3D printer is smart enough to solve these problems automatically. Cool!