Geoff Johnson » Mechanical

Alpha

Geoff — Sun, 25 Sep 2011 20:37:41 +0000

Alpha is a custom designed bicycle meant to challenge the standard for commuter cycling and lead the way to new innovations within the industry of bike components. It was created for my senior design project with a team of 4 other engineers. We worked for over 2000 hours to design and fabricate Alpha.

The main attributes of the bike are a fully enclosed belt drive system for powering the rear wheel, an electro-mechanical clutch to switch between freewheel and fixed gear riding, and an integrated electronics package which feeds out data to both a handle bar mounted LCD and an SD card.

I was responsible for designing the drive system which includes the SWIFT (Switchable Integrate Free/Fixed Transmission). It took me over 700 hours to design and manufacture the components with the help of one of my team mates. We are now in the process of patenting the SWIFT system and other novel piece of Alpha.

Our team won both the mechanical engineering and all engineering school competitions and was featured on Wired, Core 77, Gizmodo, Engadget and many more! Visit the website for Alpha for more detailed information about its conception, development and future.

SWIFT installed in the custom bottom bracket

Here is the final presentation video given to a team of judges, faculty and students at the all Engineering School Senior Design Competition.

Music Machine

Geoff — Fri, 23 Sep 2011 13:54:43 +0000

The Volcano, as my team of 3 calls it, is a self automated music machine that was created during the course MEAM 511, introduction to creative thinking course. It was a project that demanded a machine be entirely mechanical and able to play music for 45 seconds. I designed the ball release mechanism which is shown in the image below. We used MDF to build the frame and assorted materials to make the instruments. The ball release would spin and steel ball bearings would fall onto the instruments placed on the 6 different sides of the machine.

Aeroelastic Flutter

Geoff — Thu, 22 Sep 2011 23:50:36 +0000

The task of this project was to generate electricity using only wind power and no rotating parts. My team built an apparatus that could hold a tensioned rubber belt which would exhibit the phenomenon of aeroelastic flutter at just 13 miles per hour. The belt would begin to vibrate and by attaching magnets inside copper coils to one end, we were able to generate 0.064 Watts of electricity, which is enough to power a small LED.

You can see the final write up here!

Water Powered Rocket

Geoff — Thu, 22 Sep 2011 21:49:02 +0000

I designed and fabricated an apparatus for launching a custom built carbon fiber and aluminum rocket body for use with the sophomore lab course. The rocket and launcher was built to withstand over 160 PSI giving it the thrust to fly upwards of 25 meters. The base unit is made of 60 series aluminum and stainless steel, it has two ports, one for air and the other for the air pressure gauge. Water is loaded into the rocket engine through a top cap and the rocket is launched by spinning a release ring actuated by a bike brake cable. The rocket is 15 inches in length and 2 inches in diameter and weighs just 150 grams. The above photo was taken just milliseconds after release of the rocket, the water jet is visible in the upper left hand corner of the image.

Materials Testing for Engineering Labs

Geoff — Thu, 22 Sep 2011 20:24:15 +0000

This is a materials sample holder that I created during the summer between my sophomore and junior year. I was granted the Jacob M Abel internship to work on redesigning the curriculum for MEAM 247, the required lab course for Sophomore engineering students. I personally tested all the samples using an Instron machine to test for ultimate tensile strength and then created this wood block to hold them. I also took video on each test which is available on the MEAM design website. The block is about 2 feet in length and 7 inches in depth, made of maple which was varnished.