There are two videos included to help explain the mechanism. I would suggest building this out of balsa wood before 3D printing so that you better understand where things might go wrong and can adjust for them yourself if needed. It is a cool mechanism and fun to build.
Step 1: Materials & Costs
- 2 Pins / needles / tiny nails
- Rubber band
- Balsa wood (any modelling wood will do)
- X-acto blade
- super-glue (I used JET modeling glue)
The total cost for the above-mentioned materials is fairly cheap if you have the blade already. It was about $4 for the glue, $2 for the wood, and I found the rubber bands and pins sitting around my house.
The 3D printing was done through a friend of my family, so I cannot give an estimated cost using other vendors. Images of each of the CAD pieces is provided on this and other steps.