Whats the Best way to do Bumpers?

[thefro526]

As far as bumper construction, we made ours according to the guidelines set forth in the manual. (I know, suprise )

For attachment we made brackets out of aluminum "U" channel that could slip over our frame without much effort. From there we used 1/4" Push Pins from McMaster similar to part number 92384A036. We found that these worked excellently and almost never came loose during competition. The only drawback is that they're pretty expensive at ~$20 a piece.

[kramarczyk]

Originally Posted by thefro526

As far as bumper construction, we made ours according to the guidelines set forth in the manual. (I know, suprise )

For attachment we made brackets out of aluminum "U" channel that could slip over our frame without much effort. From there we used 1/4" Push Pins from McMaster similar to part number 92384A036. We found that these worked excellently and almost never came loose during competition. The only drawback is that they're pretty expensive at ~$20 a piece.

$$$ Yikes!!!

If you need more pins take a look at 98320A135.

They should be a direct replacement for a lot less. $1.39 / piece. I've used them on 3 robots over the last 2 seasons without issue.

[Peter Matteson]

Originally Posted by thefro526

As far as bumper construction, we made ours according to the guidelines set forth in the manual. (I know, suprise )

For attachment we made brackets out of aluminum "U" channel that could slip over our frame without much effort. From there we used 1/4" Push Pins from McMaster similar to part number 92384A036. We found that these worked excellently and almost never came loose during competition. The only drawback is that they're pretty expensive at ~$20 a piece.

We used similar pins at a similar price. Remember they are COTS though so buy them once and reuse them. We've used the same pins for 2 years now. Also the cost doesn't count toward your $3500 limit so build budget shouldn't affect your decision.

[PAR_WIG1350]

Originally Posted by GaryVoshol

Even if the rules would allow reuse of the bumpers, you'd be wise to look at making a new set. They get pretty beat up over the course of a year, especially if you go to several events and off-season events. The pool noodles begin to compress, and the wood starts to splinter and even crack. Besides, don't you want a fresh look for your new robot each year?

No problem, the added flexibility of the cracked plywood compensates for the compressed noodles.

But in all seriousness, if the inside of the bumpers could slide out of the fabric, then at least the fabric could be reused for probably one extra season.

[alubin237]

This past season we made two sets of bumpers. We put threaded inserts into the plywood. Then we attached the bumpers to the robot with thumb screws.

We attached the fabric to our bumpers with staples. We find that this works best. After we staple one side of the bumper we pull the fabric tight( a 2 person job) and staple it while gradually moving down to the ends of the bumpers. this leaves us with bumpers that are very tight. We like test them by flicking them if it is wrapped tight enough, you will hear a subtle drum like sound.

Unfortunately Im not sure what the best bumper design is that I've seen, there are alot of methods that have the same result.

[Hawiian Cadder]

our bumpers this year used wing nuts to attach, 2 people could change the colors in less than 45 seconds

[maverickfan138]

Our bumper design worked our extremely well for us this past year. We took some 3" angle brackets(placed in the corners) and screwed all four sides of our bumpers together in the permanent shape of the frame perimeter. We then added 1" angle brackets to attach our bumpers to the chassis. To put the bumpers on the robot, we would just slide the bumpers over the top, like how somebody would put on a t-shirt. To fasten, we drilled a hole in the 1" angle bracket and the chassis. We dropped a bolt with a loop of surgical tubing attached near the bolt head and looped the surgical tubing around the other end of the bolt. We did this on all four sides and it worked perfectly. With four students, we were able to change our bumpers in about 30 seconds.

The best bumper design that I saw this year were the ones with the folding fabric. They had Velcro on the top and bottom of the bumpers, and they would peel one side off and fold it(the seam ran horizontally along the middle of the bumper) to the other side, which was the opposite color.

[buildmaster5000]

My team used 80/20 stantions mounted to the kit rails and screwheads coming out of the plywood to fit into the 80/20. It was very secure and allowed for easy removal. For covers, we made a set that velcro'ed to the acutal bumpers. It was sturdy as well, but it might lack the visual wow factor you are looking for

[kgzak]

We did the flip method with Velcro and to attach to the frame we used threaded rod type things that stuck in the wood and we put wing nuts on them. Very Sturdy and Easily removable for Weigh in.

[MagiChau]

I thought our 2010 robot's bumper worked pretty well. One of our mentor took some time to cut and sew a red cloth cover for the main bumper, it was attached by two staples on the back I think. We had velcro and a blue cover since we didn't want to spend the time and resource to make another set that has to be reattached on and off during competition.

We had holes drilled into the robot and had bolts attached to the inside of the bumper so a wingnut could be fastened onto it and hold the bumper in place.

The blue cover wasn't asthetically nice to have on, and putting velcros on the red bumper probably didn't help, but we encountered no problems with it.

[Dustin Shadbolt]

Originally Posted by Hawiian Cadder

our bumpers this year used wing nuts to attach, 2 people could change the colors in less than 45 seconds

Same here. It was quick and did the task extremely well.

[Pjohn1959]

Originally Posted by BJC

2: What was the best bumper mounting you saw during the season, I'm talking about either functionality or looks. (on the killer bees we're all about looking good.)

Team 148 had a one-piece bumper (1 red and 1 blue), that fit perfectly over the frame of their robot. I watched them change it out, and it only took them about a minute to do it. It was also made out of a very slick material, so it would 'slip' off an opponent's bumper.

Very cool!

[Pjohn1959]

Team 118 also had a one-piece (see photo).

The cool thing about them, was that they brought extras, and were giving them to teams that had not done their bumpers at Lonestar. They brought a big stack of them, but by the end of Thursday, they were all gone.

[Brandon Holley]

This past year we used the flip method to change our bumpers which worked out pretty awesomely. Luckily we had a talented seamstress on the team that made the bumper covers for us that worked excellently all season.

As for mounting them, we used L brackets to hug the 1" box tubing that ran around the frame perimeter of our robot. We then just dropped a pin through the L brackets and the box beam. Took ~1 minute to remove all the bumpers from the robot.


Another cool thing we did in 2009 was use the same clips that hold brooms to a wall to hold the front bumpers to our robot. This was part of the rule that required 6" of bumper to be backed by a solid frame member. Because our robot had a wide intake in the front we wanted to minimize the bumper/frame member required to do this. Below is what we ended up with. It worked out great, we never had a bumper fall off and they were literally snap on and snap off.



-Brando

[Cynette]

Originally Posted by Rosiebotboss

All these methods work well. BUT, the VERY BEST way to construct and mount bumpers is in strict accordance with the 2011 FRC Manual.

Always a good reminder! Don't count your chickens until they hatch and don't make firm plans for a bumper design until the game rules are released!

Originally Posted by alubin237

... We put threaded inserts into the plywood. Then we attached the bumpers to the robot with thumb screws.

This is Team 1511's approach as well. Easy on, easy off!

Originally Posted by Brandon Holley

This past year we used the flip method to change our bumpers which worked out pretty awesomely. Luckily we had a talented seamstress on the team that made the bumper covers for us that worked excellently all season.

(emphasis mine)

You can't say enough about the talented seamstresses / seamsters who sewed fitted covers and flip bumpers this past year. As the person running the sewing machine for our team, my firm belief is that although the flip bumpers looked awesome, given the chance to do it again, our team would have two sets of bumpers.