This week I'm working with Carlos to make a self-climbing 3D printer. That is to say, a 3D printer that climbs the column or structure that it builds.

I designed the 3D printer in solidworks...

The 3D printer has 3 arms that grip the structure below it. At the end of each arm is a geared stepper motor that supplies enough torque to propel the robot upward.

We used the waterjet to cut out all of the pieces. We're still in the process of assembling but here's what we have:

Carlos put together some fabduinos which we'll eventually use to control the 3D printer.

Update:

So it was tricky balancing this, the final project, and a semester project for my Precision Machine Design class. Ultimately I didn't get as far as I wanted with this project.

It's more or less fully assembled but tons of testing and integration remains.

I designed a unipolar using N-mosfets and bipolar stepper driver using two A4953 H-bridges. Each board also has a tiny44. This allows the main controller to control the steppers with a simple step and direction protocol in which one digital input toggles a step and another digital input sets the direction of the step. This is a pretty standard interface for more fully-featured stepper motor drivers but it's nice to know you can very easily make your own.

Next Steps:

The next step will be testing the two primary subsystems: the polar gantry and the climbiing system.

One major concern I have is that the robot is too top heavy to climb stabily. My envisioned fix is to literally turn the problem on its head and have the printer descend from the ceiling on the column that it prints. It rules out the possibility of printing an infinitely tall column but hey, you have to start somewhere.

Source:

all of it