Robot Dimensions

Hey all, Team 6911 here. As we had a lot of tipping issues last year, we are planning on making our robot very long this year. Currently the chassis is CADed to be 35 x 24. We plan to use a 2 stage lift and a 4 bar linkage to get to level 3 on the rocket. This puts our lift about 3/4 back, and the gearboxes in the front. If someone can give me any input on whether or not 35 is too long I would appreciate it :smile:

Personally, I think those dimensions make for a robot that’s too narrow. 24in is only 2 feet wide. Will your gearboxes touch if you make it that narrow?

Gearboxes do not touch. I do agree that if we get broadsided we may be screwed. Any recommendations on a possible width?

You have–by my calculations–12" left in your Frame Perimeter. May I suggest using 8 of those to put your robot to 35 x 28? That’s close to one of the older, very workable sizes.

I am fairly certain that the dimensions this year is a 120" perimeter. 35x24 puts us at 118.

Right, my math was wonky.

I would sacrifice some length for width, OR…

There are no particular rules requiring your robot to be rectangular. Cut some corners off.

I’m sure that I’m just being an idiot here, but would cutting the corners off achieve?

I see some teams thinking of going to 28 inches wide. Does that sound more reasonable?

I think so. My team is going 32" by 27.5"

@Alexg were you at maximum weight last year?

@MrRoboSteve we were only about 95 pounds, which now that I think about it probably had something to do with the tipping issue.

Smaller perimeter. Think about a triangle where the legs are a robot with rectangular corners and the hypotenuse is a robot with angled corners. The sum of the 2 legs will always be more than the hypotenuse.

Quite literally this case, cutting corners saves weight.

Geez we’re at 26"x28" I feel super tiny now

And length. This was a fairly common tactic to save frame perimeter length a few years back. The catch is that if any side is <12" the entire side gets bumpers.

So if we could build bumpers that were the shape of a frame with cut corners, we could do that?

So long as you have ≥6" of coverage from every corner and full coverage on any corner less than 12", yes.

Absolutely! Matter of fact you’d be required to (definition of Frame Perimeter and bumper attachment rules work together on this). There are a number of ways to accomplish that, ranging from separate segments to each side to forming your one-piece bumpers to follow your frame.

If you need some help on that part, just ask and we’ll be happy to help check your designs.

Thank you very much. I just quickly changed the dimensions on the rails which is why nothing really lines up. So basically as long as the corners are covered with bumper, plus 6 inches on the front, side, and rear rails we are okay?

Not quite… Frame looks fine but bumper rules dictate that you cannot have 8 inches unsupported by frame and must have corners covered… The side will need some kind of standoff for bumper mounts I recommend looking at either team 111 or 217’s configurations last year.

Ah. Forgot to mention that I had to take them out for the time being to make the modifications to the dimensions. There are 2x1 standoffs between each wheel that are less than 8 inches apart, I just deleted them for now. My bad