Cupcake Wooden Pulley Assembly

Modern Cupcake batches come with printed ABS idler pulleys. These are the instructions for how to build the old-style wooden pulleys.

(If you have a machine with wooden pulleys working, we recommend printing out an upgrade! You can find the source files for the printed pulleys on Thingiverse. Print out 3 608 pulleys and 1 606 pulley and you're good to go.)

Wooden Pulleys

Each pulley should take less than ten minutes to construct. Since the pulleys are cemented wood glue, it's recommended that you build your pulleys before constructing the rest of the frame of your Cupcake to ensure that they have adequate time to dry.

Parts List

Each pulley consists of five parts:

  • two laser-cut sides (marked either "606" or "608" depending on the size)
  • one radial bearing
  • one "thin" ring which just fits around the bearing
  • one "thick" ring which just fits around the bearing

Additionally, to build the pulleys you'll need:

  • two pulley clamp parts (marked "606 clamp" or "608" clamp)
  • one bolt (either M6 or M8, depending on the pulley)
  • one nut to fit the bolt above
  • three long M3 bolts
  • three M3 nuts
  • wood glue
  • a craft stick, coffee stirrer, small brush or other tool for applying glue



1. Take the thicker of the two rings and apply some wood glue to one end.


2. Place the thinner ring on the bearing. Then place the glued side of the thicker ring on the thinner, letting the bearing keep the two rings aligned.


3. Apply some glue to one end of the assembled rings. and place them on one of the pulley sides, using the etched circle to align the side with the ring.


4. Apply some glue to the other end of the rings, and then attach the other side of the pulley, again using the etched circle to align the parts. (It may help to turn the pulley upside-down when aligning the parts.)


5. Take one half of the clamp and insert the appropriate bolts into the holes, all facing the same direction. Place the pulley on the center bolt. Be careful not to get any glue on the clamp!


6. Add the other side of the clamp and bolt it down.


7. Let the pulley dry for approximately 20-30 minutes. When you're done, unscrew and remove the clamp.


8. Your pulley is done! In all, you'll need to assemble three 608 pulleys and one 606 pulley.

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