The goal of this project was to learn how to 3D print. The driving creativity was to design a pinewood derby car to go down and up the track as fast and cool as possible.

Supplies

Materials

Pinewood Derby Car Kit
PLA Filament

RC Components

Turbine Brushless Motor
ESC 40A
Receiver
Battery (LiPo)
Transmitter

Tools

CAD software
3D Printer
USB drive / SD card
Dial Calipers
Dremel
Exacto Knife Set
Drill / Drill Press

Step 1: 3D Design

Using your preferred modeling software generate a housing for your motor. My theory of the design was based on a carburetor and Bernoulli's principle.

Version 1:

After printing this version the motor did not mount correctly and realized that the propeller extended much beyond the housing thus deeming the internal airflow design ... useless.

Version 2:

This design was significantly larger (3" diameter) allowing more airflow to pass through. I also added in side ribs allowing the 3D print to mount to the wooden block.

Sketching Tips for V2.0:

Explanatory annotations found in the cross-section wireframe view

Step 2: Slice and Print

Now save your CAD file as an STL and upload it to your slicing software according to your printer.

Once you have oriented your part and tinkered with the percentage of infill you would like, you will upload your sliced file to a USB or SD card and start your print.

After your print is finished you will want to clean off any support material.

Step 3: Carve the Pinewood Derby Block

For this step, I utilized the following tools:

Drill Press: To eliminate the majority of the material
Exacto Knifes: Used to carve away the remaining material
Dremel: Used with a sanding bit to smooth out all the edges

Carve out the amount of material you need to fit all of your components. Be sure to leave enough material to drive small screws into the wood to fasten your 3D print.

Step 4: Wiring and Assembly

Attached is a schematic/ diagram of the RC components.

I found it best to feed the 3 cables of the ESC through the small hole and then connect the motor wires. Once completed, pull through the remaining slack so the motor gets "sucked" flush to your 3D-printed housing.