Sumo Bots C

[Flavorflav]

You're going to have to ask the supervisor at your tournament. The NYS supervisor always accepts labeled voltage, but I have seen regional judges make the student run his battery down until it passes a voltmeter test.

[harryk]

I know that events aren't going to be consistently proctored but it makes more sense to just go by the labeled voltage or cell count, especially since most to all types of batteries will have a higher voltage so nobody is really getting an advantage unless someone actually played it safe and deliberately got batteries with one or two less cells

[JBoyd-NY]

Testing battery output was done in the past for two reasons: (1) a long time ago, students actually made home-made batteries to use in Mission Possible, and the only way the judges could possibly know what they were putting out was to use a volt meter to test them; and (2) when the rules talked about the maximum voltage to a motor and teams had several motors (and therefore several batteries), it was faster to use a volt meter to test the voltage available to a motor rather than try to trace the connections to determine if the batteries were connected in series, in parallel, or running to separate motors.

Over the past several years, the label on the commercial batteries has been accepted as the voltage of the battery, even though it is widely accepted that new batteries (or freshly recharged batteries) have more voltage than what's printed on the label. This only makes sense - imagine how much longer impound for Sumo Bots would be if every battery (including the spares) had to be tested for voltage. We know from previous posts that old is planning on bringing at least 9 spare sets of batteries. Testing that many batteries would make impound impossibly long, even if you had enough people at impound to assign one person to the job of testing the batteries.

There are, however, hundreds of event supervisors covering the Regional and State competitions, so its best to contact the Tournament Director and ask how they intend to verify the bot has at most 14.4 volts available to it.

[aroubitchek]

Questions for everyone: How are we determining what constitutes "sharp"?

[penclspinner]

Questions for everyone: How are we determining what constitutes "sharp"?

Up to your event supervisor I assume. Use your best judgment.

[harryk]

Really it's going to depend on the event supervisor at each event, as a general rule just don't have big pointy things sticking out and round any corners that you can without ruining the function if that part

[illusionist]

Quick question, I know it says that the max voltage limit is 14.4 volts, but would it be legal if I had a 14.4 volt battery, but used a transformer? Are transformers legal?

[ichaelm]

My first instinct was to say no, because in the past, rules for voltage have usually limited the voltage between any two points in any circuit, not just the voltage of the batteries. But that's not the case for this year's sumo bot rules. So yes, unless a clarification were made, then you could use some kind of voltage increasing device. But please realize that you can not simply hook up a battery to a transformer and get a new voltage. If you do that, you will short the battery. There are ways to increase DC voltage, such as charge pumps (for low currents) and buck-boosters, which include a transformer and some other circuitry. I'm guessing that the reason why they made the rule only apply to battery voltage is because many commercial motor controllers have internal charge pumps for driving N-MOSFETs.

[rmp509]

does anyone know where to get silicon rubber that i can put around my plexiglass wheels for my sumo bot?

[Paradox21]

does anyone know where to get silicon rubber that i can put around my plexiglass wheels for my sumo bot?

Try balloons. They have been adding traction to wheeled Science Olympiad events for years.