Deep Space is going to be ruined by Defence



“tipped robots and broken manipulators everywhere” oh the humanity… I guess I’m just getting old but I do miss the days of aggressive defense and the need for rugged design. When I started as a mentor I used to describe the game to the uninitiated as ‘hockey’ where checking was fine but sticking was not… and WITHOUT bumpers! As time went on the aggressiveness was drained out of FRC. In my humble opinion, the drain started with the addition of bumpers and continued as the games seemed to be designed towards offense heavy play requiring sophisticated design without the need for any consideration of ruggedness.

Basically, FRC has morphed from Hockey to Figure Skating.

Some may like Figure Skating more than Hockey but I think this path minimizes widespread spectator appeal.


That is the reason why we did not make a big, heavy square frame for our elevator and just went with single rods of 8020 aluminum, as our intake does not weigh a significant amount. We anticipated a lot of rocket defense and wanted to make sure that our robot was stable even when rammed.


You’d be surprised at how light the “big, square frames” can be, especially for the MUCH greater stiffness you get in return. The thing about 8020 is that its meant to be strong in all directions, equally. But usually, a mechanical system needs only to be strong in one or two directions. Without getting into the mechanics of it (which I encourage you to do- look up second moment of area), you can design something much stronger and MUCH lighter than 8020.

I dislike the stuff for that reason- it makes poor mechanical design too easy.


A properly engineered design using larger dimension, thin-wall tubing will be stiffer overall and lighter than one built from 8020. As @Inconel-oh-el stated, 8020 is not optimized for such structures. It is optimized for flexibility and ease of assembly (and re-assembly) in applications where weight is not a high priority. Some of the robots I saw that I suspect may end up being too heavy are using 8020 in their elevator.


After doing some research and looking at other teams’ elevator designs from this year and last year, I couldn’t agree with you more. My team has always sworn by 8020, but its easy to see why it may not be the best material for building elevators. While I don’t think we can change our design now, this will definitely help our team in the future with elevators.

Thanks for all your help! :smile:


You are not the only one building 90+% by 80/20 pieces. We are a team that build out of mostly 80/20 and i can verify that elevators with 80/20 do not work well.


Funny story- I joined my current team as a mentor last year. They liked using 8020 because it made structures easy to build, and easy to attach to. I didn’t like it as much, but focused on designing the intake with some students, while other members on the team worked on the elevator. (I hate being like this, but ) I had encouraged them to keep weight in mind as they designed the elevator and superstructure with lots of 8020, and the 1st stage with the 3x1 stuff. They thought it would be fine, but… long story short, the robot went into the bag without the intake at 135 lbs…

After some emergency math/discussions, we made a cut list to replace all the 8020 we could with .065" rectangular square tubing, and had the weld shop across the hall (we are based in a technical high school) TIG weld it up for us, scrapped the 2nd stage (limiting us to switch bot only), and scrounged together a few more lbs to fit the intake. Fun times.

Won states with that bot though. Lots of good lessons learned, for everyone.


My mentors like 80/20 because of the way it can slide a mm over. If you drill a hole, it’s not an easy fix. 80/20? Just shift it over.


I too, remember the days without bumpers. I also remember when bumpers were OPTIONAL and if you wanted to use them, you had to include them in your robot weight. We also used to have to include the battery too in the robot weight.

I think, the limits on defense are making the game more about who can score the most the fastest, instead of who meets ALL aspects of the challenge including handling defense.


Limiting the defense to 1 robot means defense is a challenge to be overcome with good strategy, agility and driver ability instead of something to be endured, especially when facing an opposing alliance that is not able to score very many points.


Our 2014-2017 robots had significant amounts of 8020 on them. We’ve moved away from this primarily because of weight and T-nuts sliding out of place. This all being said, 2x1 8020 is a great part for complying with the 8" bumper backing rule on WCD robots because it’s super easy to face mount.

On the defense topic, I do think having the 3rd robot play defense will be very common, maybe even close to unbeatable with 2 decent-scoring rocket bots and a triple hab 3 climb. That climb puts you ahead by 4 ball cycles, which is probably around ~30-40ish seconds of undefended robot time.


I think Peter’s main point is solid (not the one that the 6 inch drop is worse than getting hit by speeding robot, 6 inch drop is relatively benign - but) this game will drive some alliance strategy - one team by itself may not be able to dominate - as a good defender may quash them - But there is only one defender allowed so only on one side at at time - this opens up alliance strategy options - much like 2014 - though many differences also.

Great thread opened by 610 - does highlight that getting a rocket will be more difficult in Quals in presence of defense - will defense show up before elims?.. In many places at least early season teams don’t want to play defense early.


Protected scoring zones have ruined a lot more recent games than unprotected ones have.


Do you mind elaborating on this take?


I’m not bduddy, but I’m assuming that he means that having protected scoring zones makes games too “easy” to play. Each robot does their little job safely in their corner, and the faster ones wins. Having defenders makes scoring more challenging, and makes matches less predictable. It means that (as stated above) a team with worse robots but a stronger gameplan can have a David vs Goliath type of victory. I think that lots of people have “favorite FRC memories” of winning a match against a stronger opponent, which is a lot of the time only possible because someone was playing effective defense.


3 ball cycles, presuming all your robots on your alliance can at least level 1


Should have been clear with my assumption—I’m assuming you’re capping out at 2xlevel 2 and 1xlevel 3 versus a triple level 3. Obviously you can further cut that down by doing the 1923 or 4613 things.


The game play may change when there is significant depth such as at Champs, especially the strong Districts such as Michigan and Ontario. When the 2nd picks can put up decent scores on their own, alliances then have a choice of trying to suppressing or outscoring the opposing alliance.


Ah I think I just misread, you are correct.


This take is a bit too hot for me. Defense will be a factor, but in my mind the results of defense will mainly manifest themselves as a limited number of full rockets qual matches before DCMP level. In playoffs the game changes, and locking down a single spot becomes less useful to a defender.