[FTC]: Answers for an inexperienced team

[VashonRobotics]

We are a 2nd year rookie team and have a question that someone might know from experience.

If in Autonomous mode your bot tips over and becomes immobile (for example this year going over the mountain or fall off a cliff) does it stay there through to the end of the match?

Thanks

[Andrew Remmers]

Unless it manages to flip its self back over, or the alliance partner manages to do so, sadly yes I believe your robot would be stuck that way the remainder of the match. Unless I am missing something in the rules, which is a possibility.

Andrew

[Foster]

That is pretty much the case in any robotics competition, FRC, FTC, VEX, BEST, etc. once your are down, you are down. It's one of the reasons that we try not to build "tippy" robots. We teach roboteers :

• about having low centers of mass
• keeping the center of mass over the robot base
• that the center of mass changes as the robot moves up and down ramps
• that the center of mass changes as the robot reaches and lifts objects

and if needed, building righting mechanisms to stand the robot back up. While self righting robots receive huge cheers at events, it does take valuable time that you could put to better use scoring.

All part of the "Science" in action in building a robot!

[JesseK]

I predict that flipping will happen regardless of 'tippiness'. Two line-following robots on opposing alliances will meet on the mountain in autonomous. One will probably flip. The other will probably drive on top of the flipped one. More [tragic] hilarity would ensue if both flipped backwards.

Other than that, we teach that center of innertia is what we want to keep low; CoI and CoM are the same exact thing, yet CoI implies an object is in motion and can be 'pulled' parallel to the ground. Teaching this gets students to consider dynamics of design as the drive train rapidly accelerates.

[pend]

Last season we used an ultrasonic sensor to detect oncoming defensive ram attempts in autonomous against our robot, and the robot would divert to an alternative firing position if it saw the oncoming intruder. The same strategy might work to avoid a head-on collision on the mountain. We're experimenting with it. Of course, that allows the opponent to score the 10 points for crossing if you're the one who backs off. I guess it's possible to detect an oncoming mountain-climber collision and then decide to divert to crossing over one of the bridges instead. 40 seconds is a long time.

Originally Posted by JesseK

I predict that flipping will happen regardless of 'tippiness'. Two line-following robots on opposing alliances will meet on the mountain in autonomous. One will probably flip. The other will probably drive on top of the flipped one. More [tragic] hilarity would ensue if both flipped backwards.

Other than that, we teach that center of innertia is what we want to keep low; CoI and CoM are the same exact thing, yet CoI implies an object is in motion and can be 'pulled' parallel to the ground. Teaching this gets students to consider dynamics of design as the drive train rapidly accelerates.

[Sheila]

We are a rookie team and had a questions about linear gears. Are there any linear gears available for FTC teams ? We did not find anything in the Tetrix parts and not sure the LEGO linear gears would be durable enough.

Any chance we could make our own linear gear from the flat aluminum or plastic sheeting listed as acceptable materials - is something like this allowed ??

[Foster]

You can always double up on the gears so they run side by side. In VEX parts we have rack/pinion gears that we've run side by side to lift 20 lbs of robot. An important design point is to try to have more than one tooth of the gear take the load. So if you can use a larger spur gear to drive your rack gear that would help.

[Chris is me]

As for tipping, knowing the FTC kit motors I would see if you could work on a mechanism that has the power to right your robot in the case of a tip. Considering you probably have an appendage to grab batons, maybe this same appendage will be able to flip yourself back up?