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Re: Sumo Bots C

Posted: May 7th, 2011, 8:57 pm
by harryk
So for those of you competing at Nats, sadly I will not, watch out for LASA's bot, it has a turbine(which they turn on when lined up for attack, and makes a really loud scary noise) to create a vacuum under the bot to suck it to the floor. I was able to beat it with a good wedge, good driving, and a lot of luck, but I wouldn't doubt that they will be fixing it's weaknesses before Nats

Re: Sumo Bots C

Posted: May 8th, 2011, 5:05 am
by Frogger4907
That's really insightful, thx for posting.

Re: Sumo Bots C

Posted: May 8th, 2011, 6:05 am
by Littleboy
Thats actually a great idea

Re: Sumo Bots C

Posted: May 8th, 2011, 7:23 am
by ichaelm
Wow, I think it's incredible that LASA as able to pull that off! In most real sumo robot competitions, vacuum pumps are not allowed, because they can give a huge advantage in pushing power. My partner and I were thinking of putting one on when we designed our current robot, but we decided against is for 3 reasons: we didn't have nearly enough mass to spare for a good pump, it would probably limit our speed, and we would have to build an almost airtight skirt around the robot, meaning that if it was wedged up by one corner, the wheels would be lifted up off the ground by the skirt in the other corner. The third reason could have been solved by a system with shocks, I suppose, but we were just too heavy already. Anyway, the fact that LASA has been able to circumvent those problems (or at least the first) is pretty awesome!

harryk, just wondering, how did you beat it? What was the skirt made of? I'm assuming there was one. When you got under one end, did the other end wedge the robot up so the wheels were no longer touching the ground? Also, were they that fast?

Re: Sumo Bots C

Posted: May 8th, 2011, 7:33 am
by robotman
I don't think you would have to have a skirt around the entire bot.
If you just put a skirt around the area you want the pump to pull at you could make it a lot less likely that a wedge could remove the vacuum

Re: Sumo Bots C

Posted: May 8th, 2011, 7:40 am
by ichaelm
Yeah, that's another way to solve the problem. For a vacuum pump, though, you want as much surface area as possible for maximum downforce, so it would be a compromise.

Re: Sumo Bots C

Posted: May 8th, 2011, 2:17 pm
by harryk
ichaelm wrote:harryk, just wondering, how did you beat it? What was the skirt made of? I'm assuming there was one. When you got under one end, did the other end wedge the robot up so the wheels were no longer touching the ground? Also, were they that fast?

They had some kind of rubber tubing glued on the bottom to make an airtight seal, also on the outside they had an aluminum skirt with some strips of transparency sheet to fight off wedges. They had no problems with speed, because they were using brushless motors with very little gear reduction, which also meant they had a lot of problems with handling, but once they were lined up they hit the throttle and that thing flew, but in one match they lost all control with it on full throttle and it ended whizzing and spinning around the entire room at high speed( which somehow didn't get them DQed for safety reasons). When I finally had to face them I was very careful not to get in their line of attack, and getting them on my wedge was easy because by then they had smashed into so many other bots and walls that their skirt was not perfect anymore

Re: Sumo Bots C

Posted: May 9th, 2011, 10:17 pm
by topspin
Wow that vacuum idea sounds pretty cool. You give up a little control and speed for more power, which should be a pretty good trade off, especially for a team that is already flying around like crazy. Speaking of which, going really fast like that was actually an effective strategy at state. The second place team over here had a little "driver error" all over the gym floor, which let them build up to full speed and ram pretty hard. Teams like this, which apparently include the LASA, might have more trouble at nats.
But anyways, I'm wondering if a vacuum would do anything unless the two bots were in a pushing match. If a ramp gets under the LASA bot then the vacuum will just break, and if the opposite happenes then it probably wouldn't matter anyways.

Re: Sumo Bots C

Posted: May 12th, 2011, 6:20 pm
by iwonder
harryk: Was LASA the team that stored there sumo bot in pelican cases? Cause it seemed kind of small to have a vacuum in it.

btw: I was the team with the clear rc car based sumo bot.

Re: Sumo Bots C

Posted: May 13th, 2011, 5:34 am
by harryk
iwonder wrote:harryk: Was LASA the team that stored there sumo bot in pelican cases? Cause it seemed kind of small to have a vacuum in it.

btw: I was the team with the clear rc car based sumo bot.

I remember LASA having pelican cases but they never actually out their bot in it, I'm sure they had a turbine in it, they told others that, and I saw it when they were working on it

Re: Sumo Bots C

Posted: May 13th, 2011, 7:24 am
by iwonder
That's lasa for you... Seemingly unending money and time.

Re: Sumo Bots C

Posted: May 13th, 2011, 5:07 pm
by ichaelm
Well, you can't really assume that; you never know what they made their vacuum out of. It may have just been as simple as a couple computer case fans, or even a unit from an old cordless vacuum, although I doubt the latter would be light enough. harryk, did you get a good look at the vacuum unit?

Re: Sumo Bots C

Posted: May 13th, 2011, 5:27 pm
by iwonder
Didn't think about a computer case fan... That sounds possible.

Re: Sumo Bots C

Posted: May 13th, 2011, 5:29 pm
by Littleboy
could you use a very powerful fan and just physically blow the other robot away?

Re: Sumo Bots C

Posted: May 13th, 2011, 6:07 pm
by illusionist
I highly doubt you could blow them away. Especially the scoop designs, which are very aerodynamically efficient from the front. I would assume a small vacuum unit was used. Not a huge one, but one that is just strong enough