FRC T-bone-ing and Hexagonal drive

[Michael Corsetto]

Originally Posted by BrendanB

+1

In 2014 3467 had some extra edges up our sides which were a necessity for our shooter packaging and not added for t-bones which ended up being a benefit in a heavily defensive game.

Personally the bumper construction & mounting is what makes this frame style very hard to pull off easily.

Can't speak for how 1678 achieved theirs, but on 3467 we had five individual pieces of plywood with the three side pieces held together by a patiently cut down/sanded 2x4 since we didn't have access to sheet metal. It was as unpleasant as it sounded and very weak. IIRC a versa gusset or two was thrown in at some point after the plywood started to crack.

I was shocked with how similar our bots ended up looking in 2014, great minds or something I guess...

We pretty much made our bumpers the same way as you guys, except replace the 2x4 with a funky looking sheet metal piece. Sheet metal was bent in-house with a vise and hammer (we were still working out of a shipping container in 2014...)

Agreed with everyone on this bumper shape not being a priority for most teams. We worked with 971 on the science behind it, mostly because we were tired of being immobilized mid-match when we just want to score points. The research we did before build definitely paid off in a game like 2014.

-Mike

[T^2]

Originally Posted by Michael Corsetto

great minds or something I guess...

Great minds think alike, weak minds seldom differ.

The bumper sides were in three pieces of plywood, connected by a sheet metal piece. The piece was bent at the workplace of one of our mentors. At first, we maintained frame-to-bumper legality by extending little metal tabs from the drivetrain to the plywood. Turns out, those tabs were pretty weak to side-on high-speed ramming. We replaced them with C-shaped sheet metal brackets extending from the drivetrain to support the bumpers, which I made by clamping the machined piece in a vise and whacking it with a mallet.

[Chris is me]

Originally Posted by Ty Tremblay

I don't think you understand my point. 1678 is a team that has the organization and resources to devote effort into properly testing and designing a hexagonal drivetrain.

I don't want this post to leave teams thinking that if they build a hexagonal drivetrain they'll miraculously be better robots when they still can't handle the game object efficiently.

A drivetrain won't win you an event, what you mount on top will.

Originally Posted by Ty Tremblay

Game breaking strategies like 2002 are not an accurate example in this era of FRC. 3rd robots aren't going to get picked for their hexagonal drivetrains. They're going to get picked for having solid, well driven drivetrains. If a team has to sacrifice either of those two in the least then they are not a team that should build a hexagonal drivetrain. My team, 319, is one of those teams.

Originally Posted by Lil' Lavery

Sure, there are exceptions, but I don't think Ty's assertion is incorrect. You're generally not going to win an event because you have a stellar drive train alone. A bad drivetrain can certainly lose you an event, but a good one isn't going to win without a functioning manipulator, drive team, and strategy.

Bumper profiles and bumper fabrics are things that are important for the 90th percentile teams trying to become the 95th or 99th percentile teams. They are far less important for the 50th percentile team. Rather than spending time, money, and manpower into researching bumper shape/material, it's probably better to invest that into, say, intake shape/material.

I agree with these two, but also want to add something. Making your drivetrain shaped like a hexagon isn't even the best way (in terms of effort to reward) to beat T-Bone pins! Drop down casters, smooth bumper fabric + solid core noodles, etc. all seem to produce a higher reward without having to change how you design drivetrains in the first place. Don't reinvent the wheel when you could just add one that drops down if you really need it.

Plus, how many times have you been a great scoring robot with a fast drivetrain that performs well, only to be beaten by T-bone pins? The teams that need to beat T-bones to become competitive already know this, and the teams who are reading this thread who hadn't really considered the problem before probably have bigger things to worry about than this defensive edge case.

[jijiglobe]

Can any teams that have used sailcloth for their bumpers give recommendations? There are a lot of options for materials. Which materials are best? Is there one that's clearly optimal for use on bumpers?