No rubber-band-powered model is complete without a handy electric rubber band winder! This inexpensive electric rubber winder for rubber band-powered planes or cars saves you the tedious work of twisting the rubber band by hand, and will help your kids or students have a lot of more fun playing.

Supplies

TT motor x 1

Mini Push Button Switch, normal open x 1

Double AA Battery Holder x 1

M3x30mm machine screw with nut x 2

3D printer and filament

Soldering iron and some wires

Step 1: Make 3D Printed Parts

I printed all the parts with PLA and 30% infill, with no support. There are two versions of the case design. One has a open frame which is faster to print and another has an enclosed case with a lid which gives it a more finished look and also helps better secure the battery, but takes longer to print.

Step 2: Assembly and Wiring

Wiring is straightforward. Pay attention to the direction of the rotation, and switch the priority of the motor wiring if it turns backwards.

With wiring is complete, use the two M3 screws mount the TT motor to the winder body. Then install the spinner coupler onto the TT motor shaft and secure it with a small screw.

Attached an optional lanyard at the bottom of the winder to free your hands.

Step 3: Use the Rubber Band Winder

The electric rubber band winder is powered with 2 AA batteries. It is very simple to use. Hold your model with one hand and hold the rubber band winder with another hand. Attached the spinner coupler to the model, and push the power button to start winding until reach the desired tension. Enjoy.