# FRC T-bone-ing and Hexagonal drive

Is T-bone-ing just when two robot clash head to head? Also what are the benefits of a hexagonal drive train?

T boning is when the front of one robot hits the side of another robot.

Hexagon drive train lets you build a robot without as severe of “corners”, might be easier to get around other robots or obstructions.

T-Boning is when one robot “crashes” into the side of another robot. It’s one of the most popular and easy ways to play defense because when you ram into the side of another robot and they try to drive forward, they’re going to go in circles because the side of their robot that you are driving against can’t move. This is furthermore effective because it technically does not count as pinning a robot. The advantage of a hexagonal drive train is that you cannot T-bone them because they don’t really have a flat side to push against.

T-boning is when one team is pushing against the side of another robot, creating a T shape if both robots are long or both robots are wide.

Sometimes hexagonal bumpers help so that a team can only push their bumpers against a component angle of your side bumpers, allowing you to get out of a T-bone. Depending on how the team T-boning you orients themselves, hexagonal bumpers may not work.

Watch defense played on 971 in this match. Occasionally when a robot makes contact to the side of their robot, they can roll out quickly. Occasionally they can’t. https://youtu.be/G07Ci0VcUjs?t=40s

It certainly can’t hurt to make your bumpers hexagonal, but you should ask yourself two questions before you decide to do so.

Is my team a major target of defense?
Is this the most effective use of my resources in handling defenders?

T-bone-ing is when one robot’s front pushes another robot’s side. If the robot being pushed has traction wheels, this increases the friction on the pushed robot’s wheels to the point where it cannot move. It is debated whether or not this should count as a pin, but as of 2014 it did not.

By hexagonal drive do you mean a normal robot with a hexagonal perimeter or a drive system where each side has an omni wheel?

EDIT: sniped x3

Are there any technical advantages of a hexagonal drive?

A hexagonal robot (if done correctly) is less susceptible to T-bone-ing in most cases. Other than that, not really. I usually find that the benefits don’t outweigh the consequences. They are more complicated to design and build than a traditional rectangular bot, so you may want to choose to stick with a more basic drivetrain and work on making a kick @\$\$ manipulator. That’s up to your team based on your team’s resources and how your team wants to play the game.

P.S. If you are going to make a odd-sided drive, make a nonagon. 100% of nonagonal robots have won Einstein.

EDIT - I didn’t know CD automatically sensors “curse words”

One solution to the T-boning problem that is much simpler to implement is to make your bumpers out of different types of fabric. Many teams use a high friction cloth (such as emery cloth) for their front and back bumpers so that they can T-bone other teams, while using low friction cloth (such as sail cloth) for their side bumpers. so that other teams have difficulty T-boning them.

EDIT: Emery cloth is way too abrasive to be used on bumpers

What are the consequences of a hexagonal drive then? Can you send me a picture of the nonogonal robot?

That sounds like such a dirty way to play and I love it. Kinda like pine-tarring in baseball, but for robots.

Wait is the nonogonal robot 148’s tumbleweed?

Are hexagonal drive train any better at turning?

A common thing on CD recently is just building outskirts out of sheet or tube in a pointed fashion to mimic hexagonal bases on top of a basic drive. All it really boils down to is bumper placement. See 148’s x009 chassis.

Yep, the bumper material is the most important material in the first place. A hexagon with cordura will have a lot more trouble then a square frame with nylon or sail cloth. Changing bumper material the first option a team should consider before changing their frame.

Right now on 3476, we are practicing sowing with these new materials, that’s more important to us then working with a new hex frame.

Citation Needed

Agreed. Emery cloth? That would be… surprising if that passed inspection.

I remember discussion about using polyurethane coated cordura, like what is listed here, but I don’t know if anyone has actually used it in competition yet.

I could see that happening, but emery cloth is an abrasive, not just tacky. Some enterprising student out there is reading this thread and thinking that sticking sandpaper on their bumpers will be a good idea.

Dear Enterprising Student,

It’s not a good idea.

Sincerely,

Every Other Team

The important thing to remember here is that a hexagonal frame perimeter is an ENHANCEMENT and not a necessity. Don’t sacrifice build time to design a hexagonal drivetrain unless you think that t-bones are what’s holding you back.

In my opinion, only the top ~5% of FRC teams can both benefit from a hexagonal drivetrain and have the resources to build one without sacrificing elsewhere on the robot.