Nikola the Rocket Slug!

This is a kind of 3D-printed toy car that uses a rather small rocket engine to propel itself. I originally designed it to simply roll on the ground, however I found that it tends to fly into the air, do a few flips, and often stick the landing! Although this is not what I originally designed it for, I was relatively satisfied with it's performance. However, before I go on, I should mention that although I enjoyed the unpredictability and surprise of this project, it can be VERY DANGEROUS and should be used with extreme safety precautions, for what happened when I tested, for better or worse, may not happen when you test it, so please use at YOUR OWN RISK. I thought it looked a little like a slug when I finished designing it, so I decided to add a face to the front to play into that theme. I hope you enjoy this project!

3D Printer PLA/3D Printer

A10-3T Model Rocket Motor

4x 10mm Bore Ball Bearings

Any strong glue that can bond PLA plastic and metal

Download the main part of the rocket slug I designed in Autodesk Tinkercad below, and 3D print it with the following settings:

1. 100% Infill
2. 0.28 mm layer lines
3. Tree supports, though only touching build plate

Although these settings worked well for me and my Ender 3 V2, if you have a different printer, I highly recommend finding the settings that work best for you.

Next, attach the ball bearings by putting glue on the axle-like rods on the bottom of the slug and sliding the ball bearings on. I used hot glue, which worked well most of the time. However, in one test the ball bearing came off, so you may want to experiment with a stronger glue, or at least use more glue than I did.

Slide the A10-3T rocket motor into the lower hole on the slug. Then insert the igniter, followed by the plastic plug, both of which should be included in the rocket engine pack.

Find a flat, non-flammable area away from people. Clip on your model rocket igniter, take several steps back, and insert the safety pin.

Cross your fingers, take a deep breath, and press the button!

REMEMBER, when the slug appears to be finished, don't come near until it has farted out a small ejection charge!

I apologize for the lack of camera quality in the videos.