MCRC#8899: Tesla Competition Bot 1.0 Reveal

Hi, folks! I promised a while back I would do a reveal of our first competition bot this year, so here it is. We’ve decided to go in an entirely different direction for TCB 2.0, but I figure that this might be able to help other teams in some way. Even if our design is not used, there is a lot to take away from all of the lessons we have learned as a team.

Specs:
4 motor Mecanum Drive (Ended up changing it to tank drive anyways)
4 motor, 5 stage Scissor Lift (geared 21:1)
Initial plans for a 5 cube needle intake, ended up changing it to 1 cube due to lift stability issues
We originally had our base raised up off of the ground, with the intention of driving over cubes.
Skyrise Plunger Intake

This robot had a lot of firsts for us, as in: this was the first time we’ve ever used CAD to design a robot, the first time we ever built a scissor lift, and the first time I used a programming language other than EasyC for a competition robot. We learned a lot of important lessons from this robot, even when it seemed like a lot was going wrong. I have two sets of photos: photos from our initial CAD model, and photos of our robot in real life.

The biggest lesson I learned is that while CAD is an extremely useful tool for designing robots, it will not always translate well into the real world and you need to take other things into account. Keep in mind, we also began designing this robot as soon as the new game was revealed back in April, and we had to wait until summer was over to acquire our parts. My computer wasn’t powerful enough for me to be able to simulate how the robot would behave in real life, and as such, we ran into several hurdles during the build. The biggest issue was the instability of our scissor lift. Once we changed our intake to not be so tall and cumbersome, we still had swaying and stability issues, but it was way more managable. Our intake ended up as a much simpler hook design.

Ultimately, our robot ended up being able to do everything we needed it to do (score on posts, build all of the skyrises, score on skyrises) but it couldn’t do it fast enough, and we had to impose a limit on how high our lift went due to stability issues. I’m happy to say we did get in plenty of practice time with our machine, instead of building right up to the competition and going in without any experience whatsoever. It just goes to show how effective driving practice really is. I am also happy that we won the Build Award at Leesburg.

There was a lot I would have liked to accomplish as far as code goes, but due to the hurdles we encountered, we ended up spilling our build time over into drive/programming time. I was also hoping to write a control system for the lift to help with stability, in addition to some more refined autonomous routines. (Also, as a side note, the judges said we were extremely close to winning the design award, if it wasn’t for the fact that we did not include our code in the notebook. Other than that, they really enjoyed the interview!)

In the end, we still learned a lot from this robot and from Leesburg. We are currently very close to finishing our next design, and are excited for what’s to come. Our next competition is in January, and we plan to get in plenty of driving practice as well.

Let me know what you think! I’m happy to answer any questions as well.

CAD Renders: http://imgur.com/a/wJpLX

Photos: http://imgur.com/a/NUtTl

By the look of it, you didn’t have any crossbars connecting the two sides of the scissor lift. Was there a reason why you chose not to connect them? And did you have any issues with lifting more to one side or sway/tilt of the the lift?

Our crossbars were actually made out of lexan, which might be why they don’t show up in some of the pictures. We also learned that lexan is not a suitable material to make crossbars out of, since the bars were not rigid enough (even when bent into an “L” shape, which is what we did)

The issues you described were some of the more problematic parts of our lift, and is what I was referring to when I mentioned the instability.

Ah ok, that would make sense why it didn’t look like they were there. Overall I imagine that it reduced the weight of your lift by a lot.

In its entirety your robot look really good! Good luck this season!

Wow. That looks really tall even not raised…

Can 1:21 handle this seemingly impossible lifting task? Just throwing out my doubt. 5 stage lift is a huge amount of slack.

It is like this every time. I started with a 3 stage scissor, good skyrise capability and 2 cube capacity. Then I see 3 cube capacity bots are the true bombs. So I am designing a 3 cube one. Now there is 5 cube. Should I change my design again? :stuck_out_tongue:

My recommendation: stick with three cubes for now. Although we had the capacity to lift five cubes, and our lift had no trouble holding five, it seriously messed with our lift stability to the point where the lift would start veering off to one side or the other. We ended up having to change our entire intake to fix our lift stability, which we still had some issues with after that.

I agree. Three cubes seems to be a popular capacity at high level games. I am still curious, being that high, wouldn’t the robot still be able to tip despite the weelie bars?