It’s been a while since my last post. 2020 has thrown everyone for a loop with COVID-19 and remote EVERYTHING and day to day life as a junior at MIT has been quite different. However, while I could rant for an entire post about my thoughts about “long-term” remote learning, this post is about the opportunities to work on projects I now have since I’m at home!

There are countless projects that I have started and haven’t finished, and I’ve recently added one more to that list: an indoor rowing machine! If you don’t know who I am, you might think that I must row or like to exercise given my new project, but I’m probably the polar opposite of that. Instead, my obsession in building this exercising machine stems from a conversation I had with my Aunt over Labor Day weekend.

My cousin does crew¹ and she borrowed an erg² for the summer. It was one of those fan type ergs³ that uses air to create resistance to each stroke. Because of the design, the machine took up a considerable amount of space. So, my aunt was wondering if I would be able to replicate something like the Hydrow; a new erg that doesn’t have the fan. For context, the Hydrow, isn’t really a traditional erg and more of a “home trainer” with a touchscreen and all. It seems like they are trying to emulate Peloton but for rowing instead of biking. Because of this, the machine is priced super high and requires a subscription to use it. My aunt really only cared about their compact/sleek design. While I do believe in my abilities to build things, the “Geoffrey version” is usually a couple tiers down from the real thing; and that’s if I even finish making it, so I didn’t promise my aunt anything. However, I just couldn’t take my mind off thinking how it COULD be done. How do you create “constant” resistance across the entire length of a stroke but have it be adjustable.⁴ The answer I came up with? MOTORS!

From robotics and the single control class I took last semester, I know that with the right sensors and control loop, I should be able to use a motor to provide constant but adjustable resistance. The possibilities for future extensions to this like a weight machine without weights also seems doable. The more I thought about it, the more I had to do it. Given that everyone is locked indoors with little to no access to exercising equipment, making my own seems to be the perfect project!

However, just to be clear: this is definitely more of a project to learn than it is to actually get a working erg machine (but I obviously really want it to work!!!) I told my parents that they can go out and buy an erg for like $300ish or I could spend $700 and a bunch of time and have a new pile of parts 😄.

Since I really should be studying for my chemistry midterm tomorrow, I’ll end this post with a quick overview of my plan and will share more detailed information as the project progresses.

Geoffrey’s Master Plan⁵

• Use a 5065 brushless motor connected to an ODrive motor controller for resistance
• Sit and slide on a linear rail system made of aluminum extrusions
• Power the motor off a drill battery