2023 Frankie

The Story:

There were two main themes to the design of most of the robots this year, telescoping arms and swerve drives. For those of you not familiar with these terms, telescoping arm means it extends out like a folding telescope (haven’t you ever seen a pirate movie that didn’t involve someone named Sparrow?). Swerve Drive is kind of like the caster wheels on your office chair, but the robot can point them in any direction and drive that way.  

That is not what you will find on Frankie though.  

First of all, swerve drive is expensive. So it was going to take a big sponsorship to buy it. We actually got that sponsorship right before the build season started, but that brings us to the other problem. Since so many robots were using Swerve Drives this year, they were backordered. So we couldn’t even get ours until half way through our very short two month build season and by then we had already designed for a conventional drive.  

Second of all, we decided to go with the alternative to telescoping and make a folding arm mechanism to score with. This is not particularly innovative, multi segment robot arms are used all over the world, just look at a car assembly line sometime. It was easier to make though, however, there was a catch. See, engineering design is always about give and take. To make one thing easier means something else becomes harder. In this case, it was the ability to run and hold three connected joints where each section is affected by gravity differently depending on what position all the segments are in.  

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Ok I’m a nerd, here is what I mean. It's harder to hold something straight out in front of you than holding it when your arm is down. Ok back to the story.

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I won’t bore you with all the math but there are a bunch of equations that tell a motor how hard to run to keep the arm in position based on what angle each part is at. Put all of that math into a computer program and the arm works... right up until the motor burns out. The scent of freshly smoked motor is quite… unique… and unfortunately something we got a lot of experience with. So there is only one solution to smoked motor and it isn’t a tangy BBQ sauce.  It’s MORE BIGGER MOTORS!!! (ok and a bunch of gear reductions too but that isn’t nearly as much fun to say)  We ended up using motors SO big and gear ratios SO tall that the arm could hold itself up just by the friction of the motors and gears. Remember all that math? Gone! But that brings us to the unfortunate consequences of that decision. The arm motors were now SO powerful that they could literally twist their axles like a wet paper towel. Needless to say we got really good at swapping out twisted and broken axles.  

And that is pretty much it. We scored points in auto and teleop, managed to balance, and contributed in every match. We even got a bonus playoff spot when another robot broke down. But now, we have plans for the off-season and we will see where the summer redesign leads us.  

Oh! Almost forgot to give the explanation behind the name. It came from our co-lead mentor Robin. It is derived from Frankenstein as a result of being made of parts from all over the place and consistent replacements necessary to keep it alive. Frankie miraculously survived multiple “death blow” incidents and worked fairly well despite the not so occasional replacing of broken parts. Is very much undead, too powerful to be left uncontrolled, and has arm strength that exceeds it’s structural integrity.