3D Printed Rubber Band Dragster

Build your own gear reduced, 3D printed, rubber band dragster. 3D print files included.

• 3D Printed Parts
• Ruler
• Marker
• 2 Three 1nch Rubber Bands
• 1 Large Rubber Band or 3 Average Size
• 2 Pencils
• Something to Cut the Pencils
• Mechanical Grease (Grease that comes with most 3D printers great)

First thing you will need to do is print all the parts. I printed mine on a Makerbot Replicator 2 with a layer height of 0.2 mm with no supports for any of the parts. All the parts can be downloaded below.

You will want to slide the notched side of the 3d printed "body" piece onto the notched end of 3D printer "back" piece. This may take a bit of pressure depending on how well your pieces printed out. If the pieces seem excessively tight you can sand the notches slightly.

You will now want to remove the metal and rubber eraser end of the pencil from the wooden piece. This can be achieved by grabbing the wooden part firmly in one hand and then with the other hand bending the metal part side to side repeatedly while pulling it off.

Now measure out 3 1/2 inches on one of your pencils, mark it with the maker and the cut it to make the rear axle.

Now take the 3 1/2 inch pencil piece we just cut and slide it into the hole on one of the "large wheel" so that it is flush with the wheel as shown above. This may take a bit of pressure.

Now apply a couple small dabs of grease to the bevel of the "small gear". Then slide it into the top hole of the 3D printed car "body" as shown above.

Now take the 3D printed "driver cap" and slide it onto the 3D printed "small gear".

Now slide the rear axle slightly into the left hand side of the 3D printed "back". Then position the 3D printed "large gear" on the left hand side of the 3D printed "small gear" and slide the pencil all the way through until the "large Wheel" makes contact with the back piece.

Now slide the other "large Wheel" onto the rear axle. You want to make sure there is very little space between the wheels and the back piece but also that there is not to much pressure. The wheels should spin freely and the "large gear" should spin the "small gear".

Now slide the second, uncut, pencil into the "body".

Now attach the 3D printed "front" to the other end of the pencil.

Measure 1 1/2 inches on the remaining pencil piece, mark it with your marker and then cut it.

Now take the 3D printed "small Wheel" and attach it to the front axle.

Apply a few small dabs of grease to the inside edge of both "small wheels".

Slide the front axle into the the 3D printed "front" and then attach the other "small wheel" to the front axle.

Wrap the two 3 inch rubber bands around to two back wheels. They should fit snugly into the groves on the wheels.

Thread the 7 inch rubber band through the end of the 3D printed "driver cap".

Take one end of the rubber band and thread it through the opposite end of the rubber band. Then pull tight and attach the rubber band to the hook on the front of the car.

Spin the wheels counter clock wise to wind up the wheels, place on a smooth level surface and let go.