Sumo Bots C

[ichaelm]

I heard that the weight limit was going to be 1.8 kg this year. Don't count on it though.

[fmtiger124]

Oh how I wish they increase the weight limit

Wouldn't that just make it more of a battle of wallets? Wouldn't it be better to drop the weight limit?

Well the only way to eliminate wallet battles would be to make standard motor sizes and other specifications

But I already built my robot and spent the money based on the trials rules, if they reduced the weight limit I'd have to start all over and the money I spent is wasted

Why would you build it so early? The trial rules can change quite easily and having already used your money you could end up in quite the tight spot. It's already one of the more expensive events. The head start is nice if you get lucky and your bot is within specs on the real rules but I'd say the potential consequences of something changing outweigh the risk of getting a head start.

[robotman]

Well the only way to eliminate wallet battles would be to make standard motor sizes and other specifications

But I already built my robot and spent the money based on the trials rules, if they reduced the weight limit I'd have to start all over and the money I spent is wasted

Why would you build it so early? The trial rules can change quite easily and having already used your money you could end up in quite the tight spot. It's already one of the more expensive events. The head start is nice if you get lucky and your bot is within specs on the real rules but I'd say the potential consequences of something changing outweigh the risk of getting a head start.

[/quote]
Well it depends on how much you are building and spending.
Spending a lot and making a complete bot is defiantly a waste without official rules.
But building a cheap prototype with what you have and a few bucks isn't really a waste. I built a test platform using my Vex from RoboCross and some balsa to try armor designs

[harryk]

I competed last year at nationals, so I built it then

[Flavorflav]

The weight is 2.0 kg again.

[harryk]

The weight is 2.0 kg again.

Yeeeeeessssss!!!!!
I'm assuming that you got your rules because my friend said they got them

[Flavorflav]

The weight is 2.0 kg again.

Yeeeeeessssss!!!!!
I'm assuming that you got your rules because my friend said they got them

Yup.

[sj]

Are the Dimensions also the same as the trial rules?

[ichaelm]

Yes.

[old]

The voltage limit this year is 14.4 volts (I got the rules yesterday) but I didn't see anything saying how they were going to determine that voltage. In previous years they have sometimes actually measured the total voltage of the batteries (but that can be very tricky since some battery packs use a combination of series and parallel cells to get the final voltage and capacity), and other times the rules said that they would go by the stated voltage on the battery pack. This year there doesn't seem to be any mention of how the total voltage is to be determined. Of course we all know that a just charged battery pack is going to have a voltage significantly higher than the nominal voltage stated on the pack or cells. In the case of LiPo the cells are actually at 4.2 per cell even though the nominal voltage stated on the pack is based on 3.7 volts per cell, so a freshly charged 4 cell LiPo might read 16.8 volts even though the stated voltage will probably be 14.8 or 14.4 (some manufacturers use 3.6 as the nominal voltage of Lithium cells, some use 3.7). Typical nickel metal hydride and nickel cadmium can read 1.4 or more per cell but have a nominal 1.2 or 1.25 volts per cell. With the maximum voltage allowed at 14.4 vdc one might think that the rules were meant to allow either a 4 cell lithium ion/LiPo or 12 cell nickel metal hydride/NiCad but either of those combinations would read well over 14.4 when fully charged. This may seem like a minor issue but essentially I can't select motors to power the device until I know what power source I can use.

So does anyone have any ideas about how battery voltage will be determined?