Reflections by Brendon Sassmannshaus

ME 250 has been hands down the best class I’ve taken so far. It is also by far the most time consuming.

I am extremely happy I wound with a compatible group. My Engin100 groups were a mess. This improvement could be from more cautious selection, or that ME250 is comprised only of mechanical engineers. As a group, I feel we struggled with integrating less familiar team members into processes when one of us had paramount proficiency. I feel we did well organizing meetings, discussing what needed to get done, and conferring on our successes or problems. We could have chosen a less ambitious design to make the project a lesser degree of time sink, but that’s not “how we roll” on team Fluffy Bunny.

In the design process Marcus Brown kept extremely well broken down sub assemblies of all of our components to limit the complexity of each layer of our CAD models. I plan to keep this practice; it was a great boon. The laser cutter was an amazing convenience along with the Water-jet but not being able to press fit (esp. bearings) into products of either of these tools is limiting. 3-D printing was a large part of our manufacturing. It was cheap, versatile, reasonably fast, and took almost no supervision.

Our timing circuit for our roller was a really fun piece to design. We wound up not using it in the competition because we couldn’t trust the output of every control box being within tolerances (a small leaking current could trigger the latch and disqualify us) and the circuit went into very dark grey area in terms of the degree of freedom limitation after it timed out; the roller would get current whenever the trigger was picked up after the 70 seconds. This is pretty much signal encoding and it’s effects could be produced mechanically with two ratcheting mechanisms but upon asking Mark it seemed to be against the rules.

Similarly vague was the rule on ‘sand bagging.’ I heard during the competition that it had been ruled that you could sand bag for traction. The only other things I can think to sand bag for are momentum for a collision, and deliberately slowing your robot both of which seem pretty improbable given the speed of the competition. These rules should probably see errata.

I really enjoyed the course and got a lot out of it. However, I would recommend a better system for displaying assignments. Both on the spreadsheet and on c-tools the assignments seemed hidden in lectures and virtually non-accessible to sleep deprived students. This could be due to multiple instructors collaborating in the class.

To improve my performance in the course I might have chosen a less-ambitious project. Decepticon was a concise simple model in my mind so we went with it, but it limited our main bot to 2 degrees of freedom, had a lot of flaws, and in the end was a minor flop, though it probably could have been remedied by sand bagging the wheels and decreasing the length of wire or changing the gauge to decrease resistance.

Thank you to my team who stayed together through the 4 AM traumas.

A BIG thank you to the ME 250 staff who gave us such a great environment to learn (and sometimes make mistakes.)

~Brendon Sassmannshaus