Bumper weight

[jblay]

Does anyone know of a way to increase the weight of our bumpers? For example, could we put steel plate inside the wood backing? Thanks for your help.

[Mike Betts]

Joe,

No you can not do that.

However, the bumper design allows for optional angle along the back edge of the plywood. It does not say if the angle is aluminum or steel or what the thickness is.

This should give you ample engineering margin to insure that your bumpers are the maximum allowed weight (18 pounds).

Regards,

Mike

[GaryVoshol]

At the risk of being labeled a self-proclaimed rules expert ...

I don't see anything in the rules that specifically denies this. But in the past the Q&A has said that the only materials that can be used in the bumpers are the 4 elements mentioned in the rules: Plywood backer board, Pool noodles, Cloth covering, Angle clamping brackets. Plus associated hardware needed to put them together and attach them to the robot.

Remember, you have a maximum 18 pound weight limit for your bumpers.

Ask the Q&A using your official login found in your TIMS.

[jblay]

Thanks for the information, Mike, but where did you find that?

[Russ Beavis]

Section 8 Robot Rules - please tell me you've heard about the rules docs.

Russ Beavis

[Mike8519]

Rule R08 Sec. G and H specify that you may use a multi-part attachment system. That attachment design is left up to the team as long as it is robust enough to withstand rigorous play

[sdcantrell56]

Simple solution...use a denser wood. Locate some true baltic birch plywood. That should be a good bit heavier than generic home-depot garbage plywood and a whole lot stronger to boot.

[Rick Wagner]

Denser wood is a good way to get more weight. It's so much heavier than standard plywood that we chose not to use it this year because we got into bumper weight trouble one year when we used iron angle on our front bumper. It passed inspection after we lightened up a bit.

[MrForbes]

Weighed our bumpers tonight...8 lbs....I guess we need to find 10 pounds of something legal to add to them! We probably have enough Baltic Birch to add a couple pounds, and we could add some 1/2" x 1/8" aluminum angle...

[waialua359]

Wow,
that is actually really light.
Ours came in at 12 pounds and we thought our's was light.

Its too bad we couldnt put some of our 8lbs over, from our robot to the bumpers.

[AdamHeard]

Weighed our bumpers tonight...8 lbs....I guess we need to find 10 pounds of something legal to add to them! We probably have enough Baltic Birch to add a couple pounds, and we could add some 1/2" x 1/8" aluminum angle...

You can also use steel angle, much easier to get 10lbs out of that.

1/2" x 1/8" 6061 is around .1 if the numbers in my head are correct.

you probably want something more like 3/4" x 1/8" steel, that's about .6 lbs a foot.

[dtengineering]

There is no rule regarding the humidity content of the plywood... soak it in water for a while...

Mmm... mouldy bumpers!

Jason

[EricVicenti]

There is no rule regarding the humidity content of the plywood... soak it in water for a while...

Mmm... mouldy bumpers!

Jason

We were joking around earlier this year about taking it a step further. Why soak the plywood when you can soak the whole bumper, pool noodle and all? We would have big buckets of water in our pit, and reattach the soaked bumpers before each match. This idea was later discounted when we realized that our technique would be easily recognized when we hit another robot and water splashes all over.

[Russ Beavis]

Petrified plywood? ;)

[jgraber]

Petrified plywood? ;)

My rookie parsing of the Bumper rules and Q&A is that anything inside the bumper perimeter that you can call a "bumper attachment bracket" that is permanently attached to the bumper is fair game. An 8 lb bumper perimeter with 10 lbs of bolts to hold it on, a plywood subfloor across your whole robot that bolts upward to the frame, etc.
This could have been designed into the frame to provide a lot of frame strength, for those teams with 3lb frames.

10 lbs of bolts, where each bolt costs less than $1 would not count against the cost budget too.

Per recent Q&A, bumpers need to meet $3500 budget rule and shipdate rule.