For our final project in ENGI 210, Paul Glenski and I were tasked with combining the techniques taught in ENGI 210 to make a mechanical device using the movements provided in the book 507 Mechanical Movements by Henry T. Brown and made available online at http://507movements.com.

This required the use of the OEDK’s laser, water jet, and vinyl cutting machines along with varying hand tools and post-processing techniques to make our parts. The materials for these machines were 0.2” – thick plywood, 0.03” – thick aluminum, and 0.1” – thick vinyl sheeting (respectively). Additionally, cardboard stock, Adobe Illustrator/Google Docs/ the software needed for the aforementioned machines, sandpaper/files, spray paint, clear coat, and different types of adhesives such as wood glue, super glue, and Duct Tape were used when needed during low, medium, and high-fidelity prototyping phases of our project.

Furthermore, this final assignment was divided into three distinct stages so that Dr. Wettergreen and Douglas could assess our current progress and provide potential suggestions to help us build the prototypes and eventual final product of our device. 

Starting with the first stage due November 15th, we had to brainstorm and ultimately decide upon the intended design of our final mechanical device. This necessitated the selection of two distinct movements sourced from 507Movements so that our device could move and we also were required to create the 2D drawings through Adobe Illustrator so that the plywood, aluminum, and vinyl pieces in our game could be cut using their respective machineries. With that completed, we also needed to explain to Dr. Wettergreen and Douglas how our design would physically operate so that they could assess whether it was feasible to implement, would function effectively and stay together without falling apart, and verify that we included at least some of the movements provided to us by our 507Movements source. After some discussion, Paul and I eventually endeavored to make a game reminiscent of the annual Beer Bike Competition at Rice using multiple copies of the movements 24 and 68 shown below.

Initially, the game was designed so that two players could play it against each other simultaneously. When we excluded the plywood base the game was built upon, it soon became clear to us that every part of the game required multiple duplications of each piece so that two connecting cascades of gears could be operated by two players at once. The largest components we eventually endeavored to duplicate included 3 rectangles of 0.2”-thick plywood sheeting stacked on top of each other and which included four 0.5” and four 0.375”circular holes cut through all layers so that 0.5” and 0.375” wooden dowels could be inserted and serve as the axis of rotations that the gears of our game would eventually rotate about. Each groupings of gears consisted of two pairs of gears. One basic small and large gear from movement 24, and the single-tooth gear and its counterpart from movement 68. We had the single-tooth gear above the large simple gear on the same axle. Our machine’s movement consisted of spinning the small simple gear, which in turn would spin the large simple gear. As the one-tooth gear is attached to the same axle as the large simple gear, it would also spin at the same rate. Every time the single tooth made a full rotation, it would rotate the one-tooth gear’s ten-tooth counterpart. At first our scale consisted of the same as the one in the drawings, as we got the 2D drawings from making lines from screenshots of the movements from the website. Our idea was to have the one-tooth gear be the track the bikers were biking on while the one-tooth gear counterpart would be the lap counter, with laps from 1 to 10 (or final lap), as it had 10 teeth. Furthermore, our first iteration of the game included 11 very small slots cut through the uppermost layer of the stacks so that the aluminum bike pieces representative of each residential college had a space to slip into and stay vertical as shown below.

Before laser cutting for the first time, we decided to do a slight redesign in Adobe illustrator. First, we decided to remove the small slits for the non participating bicycle, as we thought having two permanent cyclist, one from each of our respective colleges (Jones for Jake and Weiss for Paul), would work better.  We also decided to test one groupings of gears, as doing both would not affect how well the gears and the system work, and would waste laser cutter wood that would be useful later.

After our first laser cut, we learned that all of the gears in our original design and 2D drawing were too small. So we scaled up every piece except for the size of the holes inside all of the gears as the diameter of the dowel rods did not change. After laser cutting our second iteration, we put everything together, and learned that the small and large pair of gears did not mesh well together. We recognized our mistake in immediately moving to laser cutter wood instead of first testing the gears on cardboard. We also felt the small gear in the pair was too small and would break after a lot of use, which would decrease the longevity and quality of our machine.

So, I used a gear generator to make two new gears that fit together well, one larger gear with 20 teeth, and one smaller gear with 12 teeth. This time around we used cardboard to test if the two gears worked together once they were cut. Indeed they did. We only cut the two gears in cardboard as the platform and other pair of gears worked well in our first two prototype iterations.

After learning that our new pair of gears worked well, we moved on to making the medium fidelity prototype. We adjusted our 2D drawing in a few ways. First, we really wanted it to seem as though the biker was cycling around a track, so we wanted to upscale all of the gears, so the one-toothed gear the biker would be on would seem larger and more like a cycling track. Second, we made some laser cut wood washers, with 0.5 and 0.375 inch inner diameters and 1.45 and 1.15 inch outer diameters respectfully, that would act as spacers between the gears and the platform and the larger 20-tooth simple gear and the one-toothed gear. We also increased the number of laser cut pieces in the platform to 5 as we wanted there to be more support present for the dowel rod axles. We also added larger holes to one of the platform pieces. In this layer of the platform, our plan would be to glue a washer, which would fit as the holes are slightly larger than our washers, to the dowel rod axle in that hole, so that the washer would come in contact withe platform pieces above it if the dowel rod was tried to be lifted out of the whole. This makes sure that all the dowel rods will remain in place and not be moved upwards by accident while the machine is in use.

After laser cutting the 2D file seen above and effectively putting together the machine and all of the gears and pieces working correctly we then moved onto our high fidelity final product. We still made a few nonfunctional changes to our 2D drawings before we laser cut. First, we realized that four pieces of laser cut wood in the platform was just as effective as five after testing on our medium-fidelity prototype. We would also save material and time by reducing the number of platform pieces to four. Another change we made was finally adding the second grouping of gears to our design. As there were a lot of large laser cut components for the final product, specifically the rectangular plates of the base platform, we needed to use two 32 inch by 20 inch pieces of plywood, which is why we needed two different .ai files to organize everything. We also laser cut more washers of both sizes as we needed a lot more in order to space all the pieces out correctly.

From here on out, the blog will consist of images and captions explaining my process for putting together the final product after all of the designing was finished.

Here are some images of the final product all put together. Also at the end are links to the video of our machine in action as well as the mini powerpoint.

Here is our powerpoint slides.

Here is our final product video.

Thank you!