Build your own gear reduced, 3D printed, rubber band dragster. 3D print files included.
Step 1: What You Will Need
- 3D Printed Parts
- 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)
Step 2: Print All the Parts
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.
Step 3: Connect the Body Piece to the Back Piece
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.
Step 4: Remove the Erasers From the Pencils
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.
Step 5: Cutting the Rear Axle
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.
Step 6: Connect the First Wheel
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.
Step 7: Apply Grease and Insert Small Gear
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.
Step 8: Adding Driver Cap
Now take the 3D printed "driver cap" and slide it onto the 3D printed "small gear".
Step 9: Adding the Large 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.
Step 10: Adding the Second Rear Wheel
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".
Step 11: Attach Pencil to Body
Now slide the second, uncut, pencil into the "body".
Step 12: Adding the Front
Now attach the 3D printed "front" to the other end of the pencil.
Step 13: Cut the Front Axle
Measure 1 1/2 inches on the remaining pencil piece, mark it with your marker and then cut it.
Step 14: Attach Front Wheels
Now take the 3D printed "small Wheel" and attach it to the front axle.
Step 15: Adding Grease
Apply a few small dabs of grease to the inside edge of both "small wheels".
Step 16: Attach Front Wheels to the Frame
Slide the front axle into the the 3D printed "front" and then attach the other "small wheel" to the front axle.
Step 17: Attach 3 Inch Rubber Bands
Wrap the two 3 inch rubber bands around to two back wheels. They should fit snugly into the groves on the wheels.
Step 18: Attach 7 Inch Rubber Band
Thread the 7 inch rubber band through the end of the 3D printed "driver cap".
Step 19: Attach 7 Inch Rubber Band
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.
Step 20: Wind It Up!
Spin the wheels counter clock wise to wind up the wheels, place on a smooth level surface and let go.