Remedy a too dropped center?

[Al Skierkiewicz]

Casey,
Future inspectors should point at duct tape and make the same warning. What we are most fearful of is a hard crash launching ballast at people along the side of the field and if you climb, we don't want ballast falling on someone that does not have a hard hat. Since I have seen some incredibly hard hits this year, (enough to tip robots) launching is a big concern.

[vikesrock777]

Originally Posted by MrForbes

Normally I'd ask for a picture, but in this case I'll ask for video, with narration describing what it is you are attempting to cure.

Looking through the videos available, these are the best I could find.

https://www.youtube.com/watch?v=OMZSpcRabzE

If you look from ~4:50-5:00 you can see quite a bit of mild rocking.

https://www.youtube.com/watch?v=6ezIW5mEOdA

From ~1:15-1:40 and then again a little bit as the robot leaves the feeder station around 2:45.

In both of these examples the severity of the tip is somewhat mitigated as by this point the driver was reluctant to switch to high gear as much because of the rocking.

@GUI- yes, it is an unfortunate amount of weight up there. We are also looking into ways to reduce the weight of our shooter assembly (our withholding allowance) but hemorrhaging it entirely for the sake of maneuverability doesn't seem like an optimal tradeoff unfortunately.

[artdutra04]

A powerful drivetrain, grippy wheels, an 1/8" drop, and a heavy shooter up very high can produce those same results. With short wheelbases, I would probably drop less than 1/8", or may not even drop at all (depending on the exact wheelbase configuration).

Since you are only 95 lbs, add weight as low as you can and as centered as you can in the robot. A massive steel part an inch above the ground in the middle of the robot would be ideal.

Another potential cause is to check your drivetrain speed controllers, and move the brake/coast jumpers to coast mode. Also, check your driver to make sure they are not slamming the joysticks to full forward and reverse, you want to smoothly ease into all movements.

[meibnotu]

Originally Posted by artdutra04

A powerful drivetrain, grippy wheels, an 1/8" drop, and a heavy shooter up very high can produce those same results. With short wheelbases, I would probably drop less than 1/8", or may not even drop at all (depending on the exact wheelbase configuration).

Since you are only 95 lbs, add weight as low as you can and as centered as you can in the robot. A massive steel part an inch above the ground in the middle of the robot would be ideal.

Another potential cause is to check your drive train speed controllers, and move the brake/coast jumpers to coast mode. Also, check your driver to make sure they are not slamming the joysticks to full forward and reverse, you want to smoothly ease into all movements.

@artdutra04 In at least one of the videos we were definitely doing that, but that was to resolve an jamming problem so that accentuated the rocking. Typically the joystick motions are much smoother, but it still resulting in tipping. Hence the thread

[MrForbes]

It looks like you have a wide, tall robot, which is pretty much gonna be a tippy robot, no matter what you do with the center drop. Most wide robots have only 4 wheels, since you don't really need dropped center wheels to make them turn reasonably well.

If I'm mistaken about the design of your robot, please describe it better (including dimensions for wheelbase, track width, etc), post some pictures, or something....it's hard to see it in the videos, I had to watch them a few times just to find a robot that looks like it might say 4080 on the bumpers.