Project Overview:
For our ENGI 210 midterm we were tasked with creating a physical model of one or more of the 507 Mechanical Movements website. A lot of our inspiration was taken from this youtube video we found online. At the end of this project we had to use the plasma cutter, laser cutter, and vinyl cutter, along with turning in a deliverable working model and a slide deck outlining our work.
The Process:
For the first check in Jeff and I drew a couple 2D models. We were seeking after a “wave” movement. The goal was to create some sort of mechanical wave in reminiscence of the summer we spent in Costa Rica together. The design incorporates rotational movement on the inner shaft, which in turns creates translational movement onto the beams resting on top of the shaft. By inserting circles attached to the inner shaft at different positions this would push the beams up and down in a wave motion, thus achieving our goal. After more extensive sketching we were ready to progress into using CAD.
Sketches
Before laser cutting we made a proof of concept model. We used cardboard, tape, a single bearing, and some wooden dowels. We noticed from our model that we would need some sort of guides to not let the beams slip off the shaft, and that we would need to offset the holes for two shafts in order to keep all of the beams level at the top. After ensuring that our current plan is feasible and would work we finished the CAD and began to laser cut.
Proof of concept model/low fidelity
After we laser cut our pieces we began assembly of our medium level fidelity prototype. A short break for fall recess and then we were back at work. There were quite a few things we noticed and wanted to change for our high fidelity prototype. First off the shaft we were using was wood and we immediately noticed it was creating too much friction for the beams when they would slide on it. We initially switched to a brass rod but the rod had a very small radius and would bend due to the weight of the beams. We settled on a carbon fiber tube from the dowel rack. This in turn meant we had to change the design of the beams as well. Due to the different shaft size we had to recut to accommodate it. We redimensioned the box and took out the back wall for aesthetics. The most important change to our medium fidelity prototype was the guides on our beams. Instead of using small wooden blinds, almost like what a horse wears to narrow its vision, we switched to combining the spacers and guides into one functional piece. This meant we laser cut some pvc and then inserted them in between each beam onto the shaft rather than onto the beam. This change not only kept the beams significantly more in place but also reduced friction when the beams were moving. After identifying the steps we wanted to take for our high fidelity prototype we began the final cram of work.
Medium fidelity prototype
After assembling our working box we then moved from prototyping to final touches. For example we were required to use the plasma cutter and the vinyl cutter for this project. We wanted to put something on top of the wave to ride it, so we decided on a surfboard that we would cut on the plasma cutter. Then we spray painted the top orange (both Jeff and Walsh love the color orange) and cut a thrasher sticker on the vinyl cutter for the bottom of the board. We also then started designing a crank for the shaft to make it easier to spin. A simple design was just fitting a circle onto the main shaft and then adding a handle along the edge of the circle to grab onto. This also allowed us to raster our names, semester and year, the mechanical movement, and pura vida inside a heart. We sanded down all of our pieces but decided not to stain them because we liked the way the wood looked and contrasted the surfboard. This was our final model!! Video link to our final fidelity model.
High fidelity prototype
Reflection:
Things we would like to work on in the future:
- One of the beams is a little jumpy and we aren’t sure why, so exploring that and fixing it would be something we would like to work on
- Next time we would make a larger surfboard/attach it to the beams in a more creative way. We liked having it detachable but it could also be cool seeing it more incorporated into the wave motion
Our project combined the use of many different machines and skills that we learned over the beginning part of this semester. It took us through the entire engineering process and we had to make three different models before settling on one that was up to our standards. After finishing this project we both feel like we have improved our individual skills with the laser cutter, the plasma cutter, the vinyl cutter, and several different methods for post processing! This has been hands down the most rewarding project we have done and seeing our finished project is a great feeling.
Coast Estimate:
- Material
- Wood: 50$
- Bearings: 4$
- Metal: 5$
- Tube: 35$(apparently, per Jeff)
- Acrylic: 7$
- Spray Paint: 5$
- Vinyl: 2$
- Time Cost
- 20hrX15$=300 $
- Overhead: 150$
- (laser cutter, vinyl cutter, plasma cutter, etc.)
Total: 558 $
