Our Wooden Carousel | ENGI 210: Prototyping and Fabrication

Allison Brown and Haley Schierwagen

Overview

For our mechanical model, we decided to create a carousel that translates rotational movement into vertical translation movement, similar to the cam mechanism of mechanical movement #96, by gliding over a wave track. We designed our components in Adobe Illustrator and then laser cut them. To finish our prototype, we used wood stain and spray painted with a vinyl stencil.

Design and Planning

For our base, we wanted a hilled track, so we drew out arced segments that decreased in arc length to make 4 tiers and planned on gluing them together and sanding them down into a smooth hill.

For our carousel animals, we knew we wanted to use dowels as the axles and designed rounded skis to glide over the hill track. To create the joint, we decided to use 1/4″ dowels threaded through a hole in the dowel and holes in the skis. We tested this concept with low-fidelity materials by cutting the skis out from cardboard and attaching it to the dowels.

For our axle, we created two interlocking pieces that has finger joints to connect to a circular disc with a short pin to attach to a bearing. Additionally, we added a shelf on our axle to support the floor of our carousel.

Fabricating the Individual Components

We started with our base because it was crucial that we get smooth hills in order for our model to function. We glued our arcs segments together with wood glue and then used the belt sander to turn our distinct layers into a smooth incline. We glued the ramps onto the base and then used an orbital sander to smooth out the entire base and track.

Next, we worked on our axle. We slid the two pieces together and then glued the finger joints into the circular support. We didn’t glue the long segments of the axle together, so we decided to add an X cutout to the ceiling to hold the axle components in place.

After that, we started working on the skis and dowel axles. We laser cut the ski components and then glued them together. We used a drill press to put through holes through the bottom of our dowel axels. After assembling our first ski and dowel axle, we assembled the device as best as we could to test its functionality. One issue we noticed was that the ski rotated as it rode over the hills. To solve this, we decided to add channels to the floor and a peg to the dowel axle to reduce the rotation of the assembly and provide more support to the dowel axle.

Finishings

We did a lot of sanding on the base and the feet to make sure everything was smooth.

We stained our wood pieces with dark walnut stain. We sanded the base after staining to make sure it was smooth enough for the skis to glide. We added lacquer to the base to give it a smooth finish.

We clear coated the animals before attaching them to the dowel axles.

We used the vinyl cutter to make a stencil to spray paint a design onto the roof.

Assembly and Troubleshooting

One of the biggest challenges of our model was that we couldn’t really test it without all the components and there was a lot of individual parts that had to be assembled in a specific order. Before gluing everything together, we put all the components and tested the mechanism. We noticed that there was a tolerance issue with our dowel axles. We had used two different dowels with supposedly the same diameter to make our four dowel axles and there was a slight difference in the diameter, which caused two of our dowel axles to jam. To remedy this, we used a dremel to shave out some of the material inside the dowel channels so the axles could slight more easily. Because our model could not stand on its own before gluing, we often had to have one person hold the model while the other person worked on it (like when we used the dremel for example).

We also made use of our “almost” box from the laser cutting assignment to support the model as we tested certain things.

Once we were confident we had removed enough material, we started to glue. At this point, we needed even more hands, so we got some help from our friend, Patrick. After gluing it all together, we lacquered the floor and the roof to match the finish of the base. Then, we added some butcher block conditioner so the mechanism would glide more easily.

The Final Product