At the start of my winter break nearly a month ago, I bundled a small assortment of my belongings in the car and began the long drive down to New Orleans alongside my good friend Liam. Together we worked closely with Matt at Nightshift to design and fabricate a working prototype electric bike over the span of three weeks. We began with an old beat up Katrina BMW R75/5 from 1973 and reworked the bike with a Nissan Leif Battery pack and a large 10KW rear hub motor. Many of the parts for this build were lifted from Matt’s previous Leafy Savage build since this iteration is only intended as a minimum viable prototype. We also purchased two 18650 Tesla battery pack modules consisting of 444 cells each, which we intend to use in the final build. Weekly progress posts can be seen here, here, and here. A final gallery of our prototype is available here. Many thanks to Matt, a gracious host and a gifted educator.
I have recently rediscovered an old wordpress post published in Spring 2015 regarding my final project in Computational Physics. My good friend Matteo and I completed the project over about a month and posted weekly updates to our class blog. All of our code is hosted on the site so you can still download the Matlab files if you’d like to check them out yourself.
As a culminating project in Digital Electronics, my partner in crime Liam and I built a multi-color Etch-A-Sketch game which was hosted on an FPGA board. The board connected with two rotary encoders used to control the cursor and a VGA monitor. The game was coded in VHDL and was completed at the end of our spring term in 2016.
A comprehensive report of our project is hosted publicly here.
Finally coming around to putting up this post of my frame building project over the summer. Below I have dumped a ton of photos in no particular order. This project was an immense undertaking with extremely high rewards. I could not have completed it without my good friends Laurence of Boxy Bikes and Joe of Cobra Frames. I am overjoyed to have finished this project and to have produced an extremely fun and light bike that I get to ride hard each day.
The jig used for this project was initially made by Glen Swan, and much of the tooling was provided by the Ithaca Generator. The tubing is mostly Columbus and was passed on to me by a friend from school. The frame is modeled off of a Surly Pacer size 54, with slight variations to some of the lengths and angles. The initial design was created in BikeCAD Pro.
Mitering was performed using a drill press along with a custom tubing fixture, which was pretty squirrely. This was a super non-ideal way to make cuts but definitely got the job done in the end. I decided to braze my bottle bosses since they seemed too small to TIG, though this was an adventure in itself since I had never actually brazed anything before. You can visibly see my brazing improvement in one of the photos below. All other braze ons were TIGed.
Finishing the frame, I purchased a Shimano 105 gruppo wholesale from Chain Reaction Cycles, and sourced out the rest of the components from my current parts bin. I had the frame powder coated in what was supposed to be more of a clear coating but ended up looking like a stormy grey which was supposedly a biproduct of the sandblasting process. Before installing parts I also had Joe ream/chase/face the frame as well as check for some minor alignment issues. He also graciously gifted me one of his old steel lugged forks.
Overall I must have spent hundreds of hours designing, cutting, welding, thinking, and stressing to finally finish this product. It was a really large undertaking to fit in just under a couple months, especially without a direct mentor providing support. I am extremely proud of how well everything turned out, and am constantly amazed by how much I have invested in this singular physical object. The bike is a blast to ride, and I hope to begin racing it this upcoming Spring.
My dear friend Liam Grace-Flood and I spent some of our free time towards the end of the term working on a fun funky tall bike. The basic idea is fairly straightforwards: stack two bike frames on top of each other, and merge the forks with one long steerer tube. Liam and I attempted to improve slightly upon this design by creating a double fork rather than a single longer one. The longer design only utilizes two headset bearings, one at the very top and the other at the very bottom. By merging the two fork crowns and threaded steerers with an intermediate tube, we were able to use all four bearings and hopefully improve ease of steering. The only concern is that this may leave the front fork as the most vulnerable area to snapping, since a lot of force may be applied against such a small weld. I also think the new fork design ended up looking pretty sweet which was an added plus.
Despite not getting to compete due to rules compliance issues, our car still was driveable and looked pretty damn good. Above you can see some shots of my welded aluminum gas tank, stainless exhaust pipe, and a few more 4130 mounts. I think overall I’ve spent 100+ hours on this project and finally feel fairly confident with my welding. Since I had to start working on the chassis before I felt fully prepared, you can really observe my learning process by looking at the welds on the car in chronological order. I hope to bring this knowledge towards building my own steel bike frames soon.
During this past winter, along with two other Thayer students Graeme Gengras and Tyler Albarran, I built a subtractive mixed analog/digital synthesizer as a final project in ENGS 32 (Intro to linear and digital circuits). A short demo of some of the functions we acheived can be seen here.
The basic flowchart for our design is as follows:
Below you can see some of the more detailed elements of the above block diagram:
And finally, a you can see a few of the different outputs we were able to achieve. The individual waves are zoomed in images of the oscillator before the signal went through other processing. The first image shows how the key press triggers the envelope, which in turn triggers and shapes the final sound wave.
This project was a ton of fun to complete. Our final product made super funky and weird noises, and was great to play with. I think that all of us in the group were left with many ideas on how to reimagine or expand upon our current prototype. I hope to incorporate either the same or similar geometry in future projects involving sound art and engineering.