Concept Sketch
Overview
For the working mechanism, my teammate Sasha Keck and I decided to design a carousel that would be hand-powered by a crank that translates vertical rotational momentum to horizontal rotational movement. To accomplish this, we decided on laser cutting 2 spur gears that would interlock and rotate. On the carousel, the horses would be attached to poles that follow a wavy track hidden in the base, so that when the horizontal gear starts rotating, the horses would move up and down along the wavy track. At the first stage, we created Adobe Illustrator files that are ready to be laser cut for each component. The gears were produced using geargenerator.com.
Gear Dimension
Low-Fidelity Prototype
To test our idea, we created a low-fidelity prototype out of cardboard, glue, washers, and dowels. Of course, our first model wasn’t perfect. We noticed a lot of dimension issues that we needed to fix, such as wave and casing radii and heights, etc. Realizing that the horses would have a hard time lining up with the wave track, we doubled up on the horses’ thickness so there’s guaranteed surface touching between them. The pictures below show our low-fidelity prototype.
High-Fidelity Prototype
Next, we moved on to wood. Because of the differences in wood and cardboard thickness and malleability, we had to adjust more dimensions on the old pieces. There were also some problems with the stability of the pieces, which is why we tested different sizes to find the exact dimension for a tight fit between the dowels, the central columns, and the holes.
Another issue we encountered was with the gears. Because the gears were translating vertical rotational motion to horizontal rotational motion, and the spur gears weren’t the most fitting for this translation, we wanted to make sure that this intersection point is as smooth as possible. To do so, we increased the thickness for the horizontal gear, attached a short dowel to the bottom layer to prevent it from moving around, and played around with different sizes of washers to ensure that the vertical gear will always be touching the horizontal one.
Throughout the entire project, the biggest problem we had was probably the wave track and the casings. Because these pieces were curved and the kerfs between each segment are very close to each other, the pieces were often breaking or burning. After adjusting the kerfs and speed settings, we were finally able to print intact pieces. However, following the changes in the kerfs, the curved pieces no longer had a snug fit with the base. For the sake of stability, we printed out a few spacers that would keep them in place.
Post Processing
Before adding any coating, we sanded down any sharp edges, especially the uneven ends of the dowels. We wanted to preserve the wooden texture of the piece, which is why we only oiled the components to add protection. To decorate the horses, we cut out the horses from a shimmering material.
This is what our final project looks like!
Cost Analysis
- Material:
- Cardboard: The cardboard we used mostly come from delivery packages, but we can count them at $1 per box. We used approximately 2 boxes in total, which is about $2.
- Plywood: Although our final piece is only about 6″ x 6″ x 8″, we had a lot of cuts that failed. In total, we used about 3 boards. At each board costing around $6, we spent around $18.
- Dowel: One dowel used in total. At $8 per 20 dowels, we spent $0.4 on dowel.
- Vinyl: Less than 1/4 ft^2 of vinyl material used. We spent approximately $1.5 on vinyl.
- Oil: Although we couldn’t quantify the amount of oil we applied, it was most likely around $1.
- Washers, Wood glue, etc.: Approximately $1 in total.
- Equipment: Laser cutter, dowel saw, plier, brush, towel, hammer, caliber, rulers, etc. Because these all belong to the OEDK, we are going to exclude the fees associated with them.
- Labor: We spent around 10 hours per week working on this project, which is around 40 hours for the entire month. If our labor cost is $15 per hour, then for two people, the total labor cost approximates to $1200.
- In total, our carousel costs $1223.9.
Additional documents
