Suction cups used to hold position at the end of the game, powered through a single 2" bored pnuematic cylinder, can withstand forces above 500 lbs. Good luck trying to move us 
Our first ideas were to use out riggers and have 4 suction cups about that size or a little bit bigger, but after some testing we found out you could put 130 lb of suction cups if you wanted and they would do absolutely nothing. When you have a bot that weighs 130 pounds crash into you at 12 FPS your bot is gonna move thats a given, no matter how many suction cups you have.
wow…those things are humongous.
Cory
Suction cups are kinda sketchy in my view. First they are only meant to resist force trying to pull them away from a surface. Second they work best on smooth surfaces. They don’t resist nearly the same amount of force laterally. The amount of grip there gonna provide on a gouged surface is nothing compared to a good high COF >2 material.
Saying that 130lbs at 10+ ft per second is alot of bot for anything to stop. Just think of all those walls people have dented with a rampaging bot. At this point I’d put my money on a bot that has an inclined surface such as 229 and swampthing.
Watch this vid to see what I mean about the incline of 229.
http://www.clarkson.edu/~usfirst/our_team/photography/2003/2003_Build/WingTest.avi
*Originally posted by sevisehda *
**Suction cups are kinda sketchy in my view. First they are only meant to resist force trying to pull them away from a surface. Second they work best on smooth surfaces. They don’t resist nearly the same amount of force laterally. The amount of grip there gonna provide on a gouged surface is nothing compared to a good high COF >2 material.
**
It would seem to me that you have done little to no research on suctioncups. The right one can be incredibly strong and there are even some that can resist a lateral force better than an upward pulling force.
*Originally posted by sevisehda *
Suction cups are kinda sketchy in my view. First they are only meant to resist force trying to pull them away from a surface. Second they work best on smooth surfaces. They don’t resist nearly the same amount of force laterally.
Bingo! Which is why I designed an L-shaped bumper system that dampened horizontal forces and then converted them to vertical forces. Therefore, before you could even start pushing the robot across the HDPE one would have to pull up the suction cups–a difficult task.
I personally thought my system was ingenious, but my team wouldn’t even try it–possibly because it’s never been tried before. I think this bumper system would make suction cups an invaluable resource.
Is this just my superiority complex speaking or was I on to something? (It’s ok to be brutal ;))
If your speaking of an L shaped bumper that pivoted in the bend its been done in the past. Except it was used to lift the agressing bot an inch or so off the ground so it would loose traction while the L bumper equipped bot would gain some.
I still don’t see how your going to get suction if theres a gouge in the HDPE.
The possibility of gouges on the surface of the HDPE is the reason we didn’t use suction cups. We found that even a fairly tiny scratch would weaken the suction so much that even I could pull the cups off with no problem (and I’m pretty weak! ;)) We tried a number of different things … everything from gouges in the surface, to little scratches. We used plain ol’ suction cups, and we used suction cups with a vacuum. The bottom line: No matter how tiny the scratch/gouge/mark/irregularity on the surface is, the hold of the suction cup will be weakened considerably.
Anyway, your bot looks great guys. 
Good luck!
- Katie
In defense of suction cups:
Suction cups that mechanically create a vacuum are actually pretty good at handling lateral force. They are the kind that are used for moving large panes of glass. One suction cup independently definitely won’t stop 130lbs at 10 fps, but multiple ones, well placed, and backed up with good drive system, can probably stop all but the most powerful (and determined) bot.
edit- the way we tested this - a 160 student did pullups hanging on to 2 suction cups attached to a vertical pane of glass. Probably not the smartest thing, but it proves that they will hold lateral force. Also, multiple suction cups spaced out will minimize the chance that a large scratch will mess them up.
A 220 pound student on our team did pullups on two 4.5" di mechanical suction cups stuck to an enamel painted door jam. Also, I stuck one to the top of my washing machine and pushed it sideways as hard as I could and it would not budge. I even hit it with a hammer too and it didn’t really move. There’s a lot of science behind suction cups.
you have the same ones we do… good thing you aren’t coming to our regionals 
We tested a vaccum cup on our robot and it was crazy, we had 4 people pushing the robot and it barely moved!! With two vaccum cups its gonna be really hard to move someone.
We did no use the vaccum cup because of weight but we have two smaller cups that work really well as long as we clean them before a match.
I hope that teams out there won’t be coating the botton of their suction cups with gels or fluids to try to get a better seal, that would get a pretty quick DQ in IMHO.
Whats on the pink wheels? There is no really good pics of it.
If a team puts the thought into suction cups, they could be effective. I think many teams probably grabbed a plunger from the bathroom, slammed it down onto the HDPE, and then after watching it easily slide across the top, wrote off suction as an unworkable idea.
My team’s fear of suction cups is the unpredictable nature of how much the HDPE will get scractched. We’re pretty sure it’s going to have some deep gauges from things like omniwheels, robots falling over, totes falling over, flailing arms, etc.
The red tread on the tire is simply the timing belt given out by FIRST. As for the cups, a small scratch in the HDPE should not really matter. We even tested this on a surface of our HDPE which was scratched, and it did not effect it at all. The way the cups are designed, the pressure which is generated is spread out evenly over the base of the cup, for more surface area. We locked them down, created a vacuum, and had half our team try to push it horizontally from side to side and front to back, and it would not budge.
What about dirt on the HDPE…I think that was our teams concern with suction cups (and the pneumatic resources it would use)…the only time I have seen FIRST take care of the field is when the carpet gets unwound. I really doubt they’ll be shining the HDPE after every matching.
i;d like to know how dirt is going to get on the hdpe… i’d imagine they make the feild reseters clean thier shoes before going out because that could cause a lot to the rug too
*Originally posted by Nataku *
**i;d like to know how dirt is going to get on the hdpe… i’d imagine they make the feild reseters clean thier shoes before going out because that could cause a lot to the rug too **
Ground metal and rubber, dust, grease from chains, just to name a few things that can get on the HDPE. The top of our practice ramp has some hefty gauges in it, not just fine scratching. In testing our bot, we put it through some rigorous drills and hit some of the old bots we had sitting on top pretty hard. The colisions often resulted in the old bots getting knocked around and the ramp took a licking. We maybe wrong that the HDPE may look just fine after each match. Maybe FIRST will even break out a Zamboni and polish it, but it was just too risky for us to take that chance.
a little zamboni driven by a midget would be funny to watch, and serve a great purpose