Scioly.org

Paradox21 wrote:

rmp509 wrote: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.

I would also recommend rubber bands balloons work but for maximum traction thicker rubber of some rubber bands makes a large difference. This was found in my personal experiences especially last year with the mousetrap vehicle where there was a time when i used balloons which would cause the wheels to slip and spin [without moving the vehicle]. I think for this event there traction is a large component you would want the rubber that provides the greatest possible traction, balloons are good but they tend to slide much easier than some rubber bands over the wheel. Also rubber bands for the most part are very easy to put on and off to replace with limited effort needed to replace once rubber has been stressed too much.

I have a few questions about the rules:

1. Can parts of the robot be autonomous? For instance, can an action be triggered by a sensor or button on the robot? Can a pre-programmed action be initiated by a controller?

2. How many remotes and channels can we use at once? Can more than one person control parts of the the robot at a time?

Thanks!

MalvinO wrote:
I have a few questions about the rules:

1. Can parts of the robot be autonomous? For instance, can an action be triggered by a sensor or button on the robot? Can a pre-programmed action be initiated by a controller?

2. How many remotes and channels can we use at once? Can more than one person control parts of the the robot at a time?

1. The rules specifically state that the bot must be controlled by radio remote. Autonomous action by the bot would violate this rule, as the bot is not being controlled by a radio remote. A pre-programmed action that is triggered by the remote control would fit into this rule.

2. If more than one remote is used, then each needs to be able to operate on different frequencies. The purpose of this rule was to make sure that any two bots can compete against each other without radio interference. If you use two remotes and one can only operate on a set frequency, then it isn't possible to insure that matches can be set up with all possible opponents without two bots trying to use the same frequency at the same time. So long as both transmitter/receiver pairs have changeable frequencies, four sets of crystals would meet the rules requirements and insure that bots can compete without any interference (provided that both controllers operate on the same major frequency so that the extra crystals can be used in either transmitter/receiver pair.) If the two transmitters operate on different major frequencies (say 75 MHz for one and 27 MHz for the other) then you would need three pairs of crystals for each transmitter/receiver pair.

So, no programmable actions at all, remote control only. Where are people finding parts and stuff? Are any of the commercially-available kits of any use at all? My team has no robotics team or used parts to fall back on, this event could be a really big mess for us this year ...

maggymay wrote:So, no programmable actions at all, remote control only. Where are people finding parts and stuff? Are any of the commercially-available kits of any use at all? My team has no robotics team or used parts to fall back on, this event could be a really big mess for us this year ...

Honestly the commercial kits aren't very good at all, and for the price of a vex kit You should be able to purchase all the parts you need to make a decent robot. My advice would be to find a local RC hobby store and find a used remote, you can find them fairly cheap ( I got my 2.4ghz for under a hundred, which retails for $400). Then for motors and every thing else you just need to search the web

As GH reported back in June, Robot Marketplace has a 2.4 GHz transmitter/Receiver that they are selling for $42 for the pair ($32 for the transmitter, $10 for the receiver). Look at http://www.robotmarketplace.com/products/0-GWS24TR.html

JBoyd-NY wrote:As GH reported back in June, Robot Marketplace has a 2.4 GHz transmitter/Receiver that they are selling for $42 for the pair ($32 for the transmitter, $10 for the receiver). Look at http://www.robotmarketplace.com/products/0-GWS24TR.html

My partner and I got one of those, and we can testify that they work just fine. The only problem is that one of the channels will default to full-speed ahead if you shut off the transmitter before the bot. So, just remember to shut off the bot first.

maggymay wrote:So, no programmable actions at all, remote control only. Where are people finding parts and stuff? Are any of the commercially-available kits of any use at all? My team has no robotics team or used parts to fall back on, this event could be a really big mess for us this year ...

If you're looking to start really really simple, I suppose you could get an RC car from radio shack and modify it. Try to find one with differential steering (the wheels don't steer like a real car). Then you could start experimenting with different wheels, or different motors, or higher voltages. I mean, in my opinion, a custom built bot would be a whole lot better than a modded RC car, but it's a start.

Hey I was wondering where to get a three frequency controler for my bot.

joverla wrote:Hey I was wondering where to get a three frequency controler for my bot.

Perhaps you could have read the forum, to see if that question had been answered yet?

http://www.robotmarketplace.com/products/0-GWS24TR.html

From what has been seen, what angles seem to work the best for the blade of the bot?