Chief Delphi - How to build good bumpers

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Re: How to build good bumpers

If you're looking for simple start-to-finish instructions on how to construct bumpers, check out our "Bumper School" video series. Here's the link:

http://www.robopromo.com/category_s/1825.htm

I also saw some talk about different kinds of bumper materials to use. We have a video for that too. Link below:

https://www.youtube.com/watch?v=ZEGSTCd6G3w

Re: How to build good bumpers

Quote:

Originally Posted by rich2202 (Post 1516186)

I've seen a lot of sagging bumpers. If your wood ends exactly at 4'" (assuming the limit is 4"), I can guarantee you that some part of the noodle/covering will materially sag below 4". Especially after it has encountered another robot (or the wall) a few times.

As I recall, the noodles themselves are not stapled, or otherwise attached to the wood, so all that is holding up the noodles is the cloth. That cloth will loosen up.

Quote:

Originally Posted by MrBasse (Post 1516220)

I wouldn't guarantee that. Ours never have since we started focusing actual energy on our bumper design.

And properly attached cloth won't loosen up very much. If it did we would all have pants that fall off and baggy seat fabric in our cars and on our couches. Make them extra tight at first and any slop that develops will bring the bumpers to the place where you want them to be by competition time.

I'm with MrBasse. We still have some linear segments of our Aerial Assault bumpers, and they are still so tight that you can't pull the pool noodles out of the end without a real concern that the noodle will tear rather than slide. We had several matches where we were double-teamed as we did full-court runs because our alliance partners could not pick up or even reliably herd a ball down field. We had nothing but the fabric (stapled to the wood) holding the noodles in place. We have signs of fabric wear, but no loosening that would allow the noodles to visibly sag when viewed from the side.

Re: How to build good bumpers

I have a secret for newbies and veterans alike.
When you are attaching the fabric, staple one side first starting the middle and working out to the ends. When you pull tight to attach the second side, have a student or two, press down on the back of the bumper to compress the noodle a little (1/4" or less). Even if you don't get the fabric tight, when you release the bumper, the noodles will naturally push back on the fabric and tighten everything up.

Please read the robot rules carefully, the bumper rules do change from season to season dependent on game.

Re: How to build good bumpers

R21 c introduces an element teams may overlook in building their bumpers.

"C. use a stacked pair of approximately 2 ½ in. round, petal, or hex “pool noodles” (solid or hollow) as the BUMPER cushion material (see Figure 4-7). All pool noodles used on a ROBOT must be the same diameter, cross-section, and density (e.g. all round hollow or all hex solid). Cushion material may extend up to 2 ½ in. beyond the end of the plywood (see Figure 4-8). To assist in applying the fabric covering, soft fasteners may be used to attach the pool noodles to the wood backing, so long as the cross section in Figure 4-7 is not significantly altered (e.g. tape compressing the pool noodles) All pool noodles used on a ROBOT must be the same in order to maintain the desired interaction between ROBOTs in the cases of BUMPER-to-BUMPER contact. BUMPERS containing pool noodles of vastly different construction may cause a “ramp” effect when interacting with other BUMPERS." (emphasis mine)

The requirement that bumpers contain pool noodles of uniform physical shape and characteristics is a departure from prior years. As the KOP contained solid round noodles, teams using them will need to acquire more solid round noodles to comply with R21 c. Use of a mixture of solid and hollow noodles would appear to contravene this rule.

Re: How to build good bumpers

Quote:

Originally Posted by mwmac (Post 1521133)

This allows veteran teams to use the solid noodles that they have on hand from the 2015 game doesn't it?

Re: How to build good bumpers

Quote:

Originally Posted by Al Skierkiewicz (Post 1521166)

This allows veteran teams to use the solid noodles that they have on hand from the 2015 game doesn't it?

Sure does. Just thinking this is easy to overlook and, at this time of year, is likely to require an online purchase for many teams.

Re: How to build good bumpers

Quote:

Originally Posted by mwmac (Post 1521133)

I noticed this as new, too. Inspection could get interesting, as good bumpers have the pool noodles completely hidden between cloth and wood by a combination of stitches and staples. My guess is that the inspectors will check every few inches of each noodle with a "thumb test" similar to "kicking the tires" as a rough, informal way to check tire pressure on car/truck tires. Just in case, bring your stapler and sewing machine to competition!