Ethan Roby’s Rube Goldberg Machine Portfolio

I made a Rube Goldberg machine that rings a bell using 3D printing, laser cutting, and milling. Some research I did before making this project included looking up images and videos of Rube Goldberg Machines.

I started out by creating the tilters (figure 2) for the first part of the Rube Goldberg machine. I took measurements of the peg board I would be using to put the tilters on and recreated it in Fusion 360. This allowed me to figure out how big I needed my tilters to be, where to place the pivot point, and what the finished product would look like. Then I printed them on a Flashforge Finder. Next I created the ball-run section. I did this by taking measurements of the piece I would be milling it from then recreating it in Fusion 360. I then drew the path for the ball and cut it out of the model I had in Fusion 360 (figure 1) and used the fillet tool to round out the path. Then I cut it on a Carvey. Lastly I laser cut the dominos using Inkscape. I made the canvas size the same size as the piece of wood I would be cutting them from. To create the dominos I used a 2:1 ratio for the size. Increasing the size on the 1 by 0.1 of an inch every domino (figure 4). I then laser cut them on a Rabbit laser cutter.

Figure 1

Figure 2

Figure 3

Figure 4
Software I used for this project were Fusion 360 and Inkscape to design the pieces, and to fabricate them I used a Flashforge Finder, Rabbit laser cutter, and a Carvey. For taking measurements I used digital calipers, a pencil, and a notebook.

The way I used each type of fabrication is:

  • I 3D printed the tilting pieces because it would not be possible to make with the laser cutter and the milling machine would take up too much time and resources.
  • I laser cut the dominoes because I needed the speed of laser cutting and they were thin enough that it did not make sense to mill it.
  • I milled the ball-run section of my Rube Goldberg machine because I needed the 3D capability of Milling but the speed of laser cutting however without wasting a lot of material.

Some challenges I encountered was figuring out the right size for the rings that snap onto the tilting pieces to hold them onto the peg board. I overcame it with trial error over a few versions (figure 3). I eventually figured out the hole needed to be 6.7mm in diameter.

Some things I learned throughout this project were how to utilize the advantages of 3D printing, laser cutting, and milling, and that it takes a lot more time that it seems to design and create a Rube Goldberg machine.