We had to make an automata with joinery and lattice hinge for a project and this was what I used to move Pikachu's head as if he lost a fight in the French Revolution. Please see below in Step 9: References the other Instructables I combined in order to make this!
Step 1: Preparation
You will need the following:
- circular rod, such as bronze or steel wire: 2 mm thick (typical toothpick size) and 16 cm in length
- this will be the rod that controls the cam mechanism (see Instruction 1c for what the cam looks like)
- this will be used to attach Pikachu onto the flat follower (see Instructions 1c below)
- sandpaper (to smooth out the toothpick attached to the flat follower as it moves up-and-down through the hole at the top of the lattice hinge box when the rod is turned)
- laser-cut wooden pieces (3 mm thick MDF was used here) with lattice-hinge box with notched joinery as attached in Instructions below
- optional: Blu-Tack or wood glue
Step 2: Send File to Laser Cut Printer
Laser cut the file below. In the file are pieces to make:
- the lattice hinge box (edit the red lines to say anything you would like - I chose to say "Gotta Catch 'Em All" and "Pikachu I Choose You!", plus added a simple compound path of a pokeball on either side)
- Pikachu figure (head will be 'decapitated' and attached to a toothpick)
- 2 x pointy egg-shaped cams
- one would be attached to the toothpick, attached to Pikachu's head, and act as the flat follower
- one would be attached to the circular rod, and spin as you turn the rod, also known as the cam
- 2 x wooden nuts that will help stabilize Pikachu's head when it moves up and down and around
Step 3: Build Lattice Hinge Box
Build part of the lattice hinge box by joining the notches in the middle of the longest box piece to the top of one of the side pieces (the ones with pokeballs on them). If you look at the AI file image above, the ends of the long piece with lattice hinge should be the bottom of the box, and the centre of the lattice hinge box with the toothpick-shaped hole will be the top of the box. The sides of the box should be curved where the lattice hinge is. Keep one side of the box unattached for now so you can see where you are building the cam mechanism and sticking the rod through the box.
Step 4: Put Together the Mechanism
Insert one cam onto the circular rod and use Blu-Tack if necessary to fix it in the centre of the rod. Slide one end of the rod through the inside of the box to the outside of the side piece you just fixed in Step 2.
Glue the wooden nuts on top of each other like you would stack one tire on top of another tire.
Sand a toothpick so that it can move up and down through the two wooden nuts smoothly.
Attach Pikachu's head onto one end of the toothpick. Separately, glue the wooden nuts that are now one piece onto the top of the box directly on top of where the toothpick-shaped hole is. For proper placement, use the toothpick to make sure it can move smoothly up and down through the two tires and the toothpick-sized hole in the box.
Attach the flat follower on the bottom end of the toothpick so that Pikachu's head, at the top end of the toothpick, moves up and down through the top of the box without going through the top of the box.
Test the cam mechanism by making sure the flat follower is on top of the pointy egg-shaped cam when you spin the circular rod. The mechanism should look like below.
Step 5: Finish
Close the box by sliding the other side of the lattice hinge box through the circular rod and fitting the notches as you did in Step 2.
Attach the rest of Pikachu's body onto the top of the box, or wherever you like.
Step 6: Resources
- Lattice Hinge Box (simplebox-type2) by fspatz on Instructables: https://www.instructables.com/id/wooden-boxes-with-one-or-two-hinges/
- Basic Cam Mechanisms by Jonathan on Vimeo: https://vimeo.com/49266486
- Classification of Followers: http://nptel.ac.in/courses/112103174/module4/lec3/2.html
- Pikachu Shape by Arild Amland on GrabCAD: https://grabcad.com/library/automaton-mechanical-pikachu-1/details?folder_id=1241337