Sumo Bots B/C [Trial]

[Jim_R]

Discussion for Sumo Bots B/C, a trial event in New York and Nationals.

Rules:
2010 Rules

Links:
2009 Discussion

[fmtiger124]

Well, I didn't do this event last year, but some sort of wedge works best--along with a car that doesn't move to fast so you don't accidentally drive outside the ring

[inycepoo]

hey guys. i'm new to all of this robot stuff...so.
the old one from last year runs on vex...which is decent yes, but i dont think i can deal with such weak but okayish light motors for this year.
any suggestions what motors or other stuff from what brand to get?

thanks

[jadeboy]

Wait a sec ... my school isn't offering sumobots this year What's up

[Skyline1010]

The increase in size combined with a decrease in max weight is making it pretty tricky this year...that and the 14.4v battery limit. I've got a good bot going though...we'll see what happens

[gh]

I thought it would make things easier. Last year, I found the design pressure to pack as much stuff into as little area as possible a real challenge. I figured, if everyone else is also allowed to have 2.5kg within 300mm×300mm, then somewhere out there somebody has packed that much motor, battery, and wheel into their design. So to be competitive, I reasoned, I had to have that much in my design.

That more or less explained why I had to have 550-sized motors, special compact wheels, and a battery with the output equivalent of something like a motorcycle battery.

Since my site hasn't been linked to yet in this topic, I'll do it now: http://www.geekshavefeelings.com/projec ... -2009.html

In there, I explain design decisions (wheel placement, height, number of wheels, etc.), list history, and illustrate with videos of matches pictures of the bot.

[Skyline1010]

Oh, I remember that bot from NY States last year. I beat it a couple times and eliminated it, but the design is pretty sweet nonetheless.

[gh]

Oh hah, the thing was just about unusable by the time I was using it for competition. The transmitter was physically broken—one stick was loose and didn't return to center, and I swapped out a better motor controller after it shorted (heatsink touched a FET's leads, I think) and parts of the bot actually caught fire. Plus, I kind of stopped caring about SO by the time states was around. :\

[LukeThomas]

I just hope some jerk event supervisor confiscates batteries because they charge above their label, It happened in the Midwestern NY regional, their battery pack said 18 volts but read 19, the battery pack were not allowed in competition

[andrewwski]

I wouldn't have disqualified that. While it's true that you can overcharge a battery somewhat beyond the manufacturer's specifications, I don't think any team would benefit from doing so. It would be potentially dangerous while charging and would decrease the battery's life.

If the battery was labeled 18 volts and read 24 that'd be different, as there obviously would be something fishy going on, probably a swapped label or something.

But batteries are often labeled with a large tolerance, especially when fully charged. If you measure a new AA battery, it's going to read more than 1.5 volts.

The competitors should have shorted the battery until it was under 18 volts and then it would have been legal to use.