Electric Tricycles (2021 - 2023)
(I will probably use the terms vehicle, bike, and trike interchangeably throughout this.)
In the Fall 2021 Semester, I joined the Mechanical Engineering Club at Boise State. One of their projects that year was a human powered vehicle for the e-HPVC competition hosted by the American Society of Mechanical Engineers. The club was fairly small and I wanted to get involved, so I was appointed as the design lead for the team. I served as the design lead for the 2021-22 and 2022-23 academic years, and want to thank some of the more involved club members who really stood out:
Julianna Buzzard
Gavin Hamilton
Connor Barry
Oliver MacDonald
Yafa Benevidez
Gigi Brandes
The competition involved building a human powered vehicle to compete in a series of challenges including a drag race, an endurance competition, and possible surprise challenges. The scoring was based on a design review, an innovation section, and challenge performance.
The First Vehicle (Aug. 2021 - May 2022)
The first thing that we did was identify constraints on the design, and ways that we wanted to improve from previous years. We had around 100 feet of aluminum tubing from the previous year, so we wanted to use that first. It was 1.25” OD tubing with a wall thickness of .125”, so it was heavy tubing. Although this made the bike very heavy, this worked out well later. Some of the key things that we decided to focus on for this year were better steering and a higher top speed. We also wanted to improve the aerodynamics, but this was a secondary goal.
The First Rule Change!
This was the first major problem that we ran into, and it occurred roughly two or three months into the competition. ASME changed the rules of the competition, while the competition was taking place! The rule change was not insignificant either. It stated that the vehicles no longer could be only manual, but now needed some kind of electric bicycle technology. This meant that the whole vehicle now had to be redesigned. We threw out the entire frame design since there was no way to easily incorporate a motor and battery, not to mention the additional electronics required for control and battery management. We had now lost three months from an eight-month competition, and our team spent an entire weekend making up for the lost time. It’s a good thing we all enjoy doing this, right?
The Second Rule Change!
Ok, from the last major rule change we lost three months, but had made up for it after an exhausting weekend. No big deal. This one just made things worse though. Instead of the actual competition part of this design challenge, happening in April as it typically had in previous years, the competition was now taking place in March.
To recap, we had now lost four months due to rule changes, half of the competition’s typical duration. This led to myself and some of the core design team members spending a long weekend sleeping in the machine shop. We literally brought in cots to take shifts sleeping, with any time not sleeping dedicated to design work and prototyping. We went through a whole pack of dry erase markers, and I stayed up designing in SolidWorks for 36 hours straight.