UR Makers

UR Makers is a club at the University of Rochester dedicated to teaching the skills and art of creation to all students

As the president of the club, I was in charge of keeping everyone on task and organized, as well as leading our larger projects each semester.

Past "Maker" Project: Infinity Mirror Version 1.0

Presented at the Rochester Mini Maker Faire in 2016

At the time, I thought I couldn't get a circular piece of glass large enough for this project. I instead, I got a rectangular mirror, then had it custom cut into an octagon, and designed a CNC pocket cut to hide it. I then designed the frame thickness around it so the edges and corners became invisible. I then manually bandsaw cut the Lexan top panel into a circle, as the CNC machine would have melted it.

I designed this in CAD to ensure proper layer spacing and make CNC toolpaths, but didn't count on the plywood being warped. As such the final product required aluminum trim to hide gaps in the sides. It adds a cool Sci-Fi aesthetic though!

Recent "Maker" Project: Infinity Mirror Version 2.0

Presented at the Rochester Mini Maker Faire in 2017

I had always intended to make two infinity mirrors, as my sophomore roommate and I split the cost on parts to afford one for each of us. After we presented the first at Maker Faire, I let him keep it and decided to go ahead with the second.

I learned from my mistake in the last mirror and this time bought a custom rectangular sized cut mirror and annealed glass to match. Both this and the last don't actually use a true one-way mirror, but rather a 70% reflective 30% transmissive office window tint film applied to an optically clear sheet. It is way less expensive, and when using the glass provided an equally impressive result. I got the idea from an online forum dedicated to making smart mirrors.

Another small mistake here: white primer doesn't stick to the sides of MDF nearly as well as the top and bottom, so I ended up taking an orbital sander to it and spray painting the whole thing black instead of using primer and the black oil paint used last time.

This was a marked improvement over the previous version, due to using a glass panel for the one-way mirror in place of acrylic (which the tint film didn't adhere to very easily). I also made this entirely out of 1/4" layers with one 3/4" layer of MDF whereas the previous version used warped sheets of plywood recycled from a shipping crate for the thin layers. MDF is ultra smooth and flat, and it mills excellently in the CNC provided the movement speed is fast enough. The result speaks for itself!

Hackathon Project: ChairBot (2017)

In 2016 I tried and failed to make an electric go-kart almost entirely myself in this 36 hour long competition. I really wanted to make something that could move a person, but decided to stick with KISS, learning from my mistakes in 2016. Thus, I devised the simplest possible way to move a person with off-the-shelf parts: Chairbot.

The idea was: Bolt four castors onto corners of a platform, stick a chair onto it, then add drill motors with 5" wheels for drive power in the center. Differential drive meant the chair could turn in place and go forward and backward with ease. I CNC milled mounts for the drills out of cut 2x4 segments, and it all came together easily!

Originally an Arduino with a joystick was used for movement, but I swapped over to a standard RC transmitter/receiver for ease of use after the competition. We didn't win anything since they quizzically removed the hardware projects category that year, but I was personally commended for it by the organizers of the event. Below are images of the current setup.

Meliora Weekend Art Piece

Completed with an ultra short time frame of 2 weeks, all construction in only 3 days, this was a display and pedestal I designed from scratch and built for Meliora Weekend in October 2018. I spent about 3 hours in Fusion and then 15 hours of assembly time on the whole thing. The piece was commissioned by the University and was intended to be an art installation used to destigmatize mental illness, HIV, and other diseases. The upper portion was designed to hold 4" x 7" postcards with portraits of those afflicted and lots of text describing their experience, which were made by the artist Charmaine Wheatley whom I worked with on the project, and who was the University's main point of contact. I was paid for my time, though I spent a few extra hours creating the 2D part layouts in AutoCAD to laser-cut every part for the upper display from six 24" x 30" sheets of 1/8" Baltic Birch. This project was a great success and earned me a feature in the 10/22 "Hajim Highlights" engineering school memo!

The Display

The upper segment of the display features a 15 slot postcard holder and a laser etched headboard. I was given the text content by Charmaine but I needed to create a 2D CAD file for the Meliora crest and text myself. I made AutoCAD lasercut files for every part of the upper display to be tab-and-slot construction, so it is entirely glued with no screws other than to affix to the pedestal.

The Pedestal

The display needed to be elevated around 3 feet in the air to allow it to be around eye level at the top and put the postcards at a comfortable height. This piece I never designed in CAD, I just grabbed some 1/4" plywood, a ruler, and tape measure, and got to work sketching in pencil and holding up boards to figure out the dimensions as I went. 6 hours and tons of wood glue later, I had this!

UR Makers Trebuchet: ASME Pumpkin Launch

The University of Rochester has a pumpkin launching competition each year where teams compete to launch mini pumpkins (2-4 pounds each) in an accuracy competition. Designed and built over the course of three weeks, this was our entry to the competition. I designed the entire thing myself in Fusion 360 as the goal was to introduce UR Makers members to woodworking and safely handling power tools, as well as showing how to blend CAD design with the creation process. The structure of the trebuchet involves almost 250 pounds of lumber and the counterweight is designed to hold a 50-pound sand bag plus another 50 pounds of 5-pound metal weights for range adjustment. Scoring at the competition was by number of feet away from the intended target summed over four shots at a minimum of two target distances. We aimed at 50 and 100 feet. Our score total was 80, which if not for technical difficulties with our release mechanism would have given us second place among 6 other competitors. We only fixed our issues after the time limit was up for official launches and as such were not judged ahead of the second-place team who had a score of 102. First place won with just 66.

Mid-launch preparation with my team of Makers! All of my helpers on the competition day were freshmen.

This is a render of an earlier model of the trebuchet done in Fusion 360

Maker Faire 2018 Club Project: Personal Electric Vehicle

The goal of this project was to essentially make a way better version of the ChairBot. This vehicle is off-road capable, and should navigate around the whole campus easily. It was built with help from UR Makers members in the 2018 Fall semester, though I worked with them on the design and planning in the spring. This project was a huge success and was demonstrated at the 2018 Rochester Maker Faire!

We were graciously given two Odyssey Extreme PC680 batteries to make a 24V 16Ah system to power the machine. The motors are two 24V electric scooter motors which will be powering the two 13" front wheels with a bicycle chain. I designed chain guards to be 3D printed for safety, as well as a master cutoff switch easily within reach of the operator. The motors are to be controlled by two VEX Jaguar motor controllers, capable of 40A at 24V each, which we were also given for free.

The Design

All parts except the Jaguars and wheels I modeled in Fusion 360 myself, including the motors, cutoff switch, and all wooden parts. I wanted to keep the center of mass as low as possible for stability, but the wheel shafts need to be supported on both sides, hence they are running up through cutouts in the platform. This still gives 5-6" of ground clearance. I utilized knobby air-filled tires in place of active suspension, so the seat cushion is a necessity. Note this is a 'tadpole' trike, with two wheels in front, for better stability while turning.

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