4. Manufacturing and Assembly - Pinball Machine

One of the first things we did was laser cut the sides and front of the box and the linkages to see if we would get our mechanism to work. 

We put together our initial prototype, but realized the movement was not as smooth as we wanted it to be.

In order to fix that, we had to use bearings and would need to 3D print our linkages in order to fit the bearings the way we wanted to. In order to get a snug enough fit for our links, we had to do some tolerancing. On every 3D printer we used, we would test print multiple little pins with diameters 0.1 mm apart to see which size would give us the best fit. 

After changing our initial design, we decided to reprint a large slider link and laser cut two gears out of wood, one to fit on the servo and another to be attached to the front of the machine. Because we had to change the placement of the servo, we had to recut the front piece of the box.

Our initial cuts of the slot turned out to be a little too big and the bearing would slip out. Instead of recutting the front part of the wood, we decided to 3D print a railing to be glued onto the bottom of the slot. This allowed for a tighter fit and smoother movement. 

We also 3D printed a ball, and tried testing it out with our printed holder. One of the first issues we ran into was realizing the ball was a little too bouncy and would bounce out of the holder whenever it dropped into the hole. We fixed this by readjusting the sides of the box and bringing the top piece of wood a little closer to where the ball would be dropping in.

Another issue we ran into was the arc of the servo motor. Since our motor could only turn 180 degrees, we realized we either needed a motor that could turn 360 degrees, or we had to readjust our gears. Since this was something we ran into towards the end of our project, we were not able to fully fix this issue but were able to remedy this by creating a longer holder that allows the ball to reach the launcher.

We ended up 3D printing the spring-loaded launcher with no issues, but we later ran into trouble with the rubber band tension of the tabs. With some experimentation we were able to figure out a solution that worked with the cuts we had. We also ended up 3D printing obstacles for the top of our machine.