Design Backfires: Share Them Here

OK, I’ll start.

I am the lead designer on my FTC team, and Rover Ruckus’ lander prompted our robot to be able to fit under it so it could score in the cargo hold. (Which it never did, but that is another story.) So I decided to mount our power switch high on our robot to be easily accessible (and also maybe to try and show judges that we were safe and designed well). Anyway, 7548’s design lead told me that the placement could potentially trigger the switch. But, well, I replied that the switch was facing in such a way that, even if contacted, it would not be toggled, and that the switch didn’t contact the lander anyway.

So we got to our regional tournament, everything was going fine, until we were actually going to deposit a mineral in the cargo hold for the first time, and… our robot stops driving. Turns out that my power switch placement was just a tad too high when the lander has minerals in it (not to mention that all fields are a bit different from each other) and clicked itself off. Yeah.

Moral of the story: Power switches shall not be mounted so they can be toggled. Oh, and listen to others. :wink:

1 Like

So in 2017, I designed our robot’s low goal dumper and ball intake. My prototype was really good, worked well and everything, but at competition, we never used it except that one time. Basically the drive team destroyed the thing. When we took off the curved metal guide for the balls to see what had happened, we discovered that it was a crumpled metal guide. I think a gear hit it and destroyed it, but it started the trend of the drive team somehow destroying every mechanism I ever designed. 2018 my climber arm got hooked in the scale at SFR, and we got a foul (lucky us). Then the drive team somehow bent my climber arm…

1 Like

Blood sacrifice. Works every time. (usually.) Never had a robot break on us when we gave it blood!

And I am only somewhat joking. Someone on my team (usually me) cuts themself on our robot. And then it usually works fine after that.

Now, my school hates me because our FTC bots tend to destroy their parts. Rack and pinion for our elevator this year? Broken. C-channel? Bent. Axle? Twisted. (somehow) Yeah, maybe I really should design FTC robots out of 3/16" so I don’t damage anything…

Our 2017 climber had an X shaped piece of 1/4" aluminum to grab a knot on our rope. The very first match if the season we were half way up the rope and another robot from the other alliance hit us and snapped one of the 4 legs. We went the whole set of qual matches without missing a climb. Meanwhile, students from the college hosting the event were bored and decided to design and CNC a brand new climber X for us out of 1" aluminum

What a nice group of people. Gracious professionalism, or like we call it, aloha.

2011: Our minibot was just straight up bad. But our elevator had a stage which was pretty much the same height as the gap between pegs, and we got stuck to the field one match.

1 Like

Last year 100%. I have never had a design blow up in my face more than my team’s 2018 robot.

We built 2 ramps (one on each side of the robot) for alliance members to drive on top of us to get the rank point. Ultimately they took up WAY more time during the build season to design and debug than they were worth, other robots had difficulty getting on them due to the scale, they caused our CoG to be higher than we’d like which made our drive team’s job harder, and stole valuable resources away from our other subsystems, causing the whole robot to be worse than it would have been otherwise.

In the end, we tore them off between our last district event and Worlds. 0/10 bad design choice for us.
Would not do again.

1 Like

Sounds a lot like my team last year lol

The last match on Carson 2018, our elevator strap got stuck for the first time, cost us the match that we could have possibly won if that didn’t happen. Apparently, we never took the flexibility of the strap we just made into account. :stuck_out_tongue:

3946’s 2015 manipulator (there was only one). It featured a row of twenty-some #10 spring-cushioned bolts on about a 1" pitch. It worked like a contour gauge and was able to pick up a tote or RC without the need for fine alignment. Unfortunately, this meant we never did get the alignment issue worked out so we could actually stack more than about three high, or carry more than one high (though we could carry two totes side by side).
Big on the upside, the abilites to flip inverted totes (driver discovered, not designed) and to get an RC from the step got us selected by the #2 alliance at Bayou, and with the help of the RC we delivered and the half dozen totes we scored each match, we won the event. But, even with another four weeks to work on the practice bot before Worlds, we never did get a stacking capability working.