Mini Sumo
So I've been thinking about building myself a custom mini sumo. I have two Parallax Sumobots but you can only have so much fun crashing two identical bots into each other, plus I want to see if I can get some folks in the computer science department at my university to participate in some mini sumo competitions. We don't have a robots club (yet) or an engineering department so it'll just be us coding geeks.
To my question. I've seen two kits use servos for sumo movement, the Sumobot and the Mark III. The Solarbotics Sumovore uses gearmotors which are faster than the servos in the other kits and at 6v giving 76 oz-in of torque. Now I know you could use higher torque servos but I don't see it being practical (or cost effective) to modify the higher end servos. Especially metal gear ones (if that's even possible)
So what do you all think? Do you use servos or regular gear motors for your sumos and what is some recommendations for torque or speeds?
To my question. I've seen two kits use servos for sumo movement, the Sumobot and the Mark III. The Solarbotics Sumovore uses gearmotors which are faster than the servos in the other kits and at 6v giving 76 oz-in of torque. Now I know you could use higher torque servos but I don't see it being practical (or cost effective) to modify the higher end servos. Especially metal gear ones (if that's even possible)
So what do you all think? Do you use servos or regular gear motors for your sumos and what is some recommendations for torque or speeds?
Comments
I used four Maxon motors on "ExSpurt". You can find all of the details here:
http://brooksbots.com/ExSpurt.html
The speed is limited by the program to about 65 inches per second. I don't have a measurement for torque, but it is "sufficient".
Rick
I'm unsure if these gear motors will be able to either get enough momentum to have a high pushing for or be able to out push the opponent head on.
It is much better to push your opponent from the side or rear. Getting to that position is the problem that should be solved.
I haven't been concerned with the pushing power of a sumo robot for years. Instead I work on attack strategies, positioning if the initial attack doesn't work, and defensive moves.
Rick
Random question about the legality of a somewhat evil feature. Let's say a robot had a flat enough section of scoop that it could go under the opponent. Would it be legal if there was a white band on it to trigger the robots line sensor?
It also depends on several other things happening:
1. You get into a head-to-head pushing match.
2. Your scoop actually goes under your opponents scoop.
3. Your opponent has line sensors
4. Your opponent reacts to its line sensors.
5. Your opponent does not override his line sensors with his object sensors.
I've seen the strategy work in the past on a limited basis.
Rick
I made an error in my math. I used diameter instead of circumference so the speed is 10.71 inches a second and would take around 3 seconds to get from side to side.
If speed is your goal, the easy solution our high school students use is the Futaba S9254 servo. They are good for about 25 inches per second in a BOEBot.
If you want to attend a good competition, you could drive over to Peoria this Saturday for the CIRC Bot Brawl. http://www.circpeoria.org/ They have both mini sumo and 3Kg sumo.
Or, in a few weeks you could attend the National Robotics Challenge in Marion, Ohio. http://www.nationalroboticschallenge.org/joomla/ It is intended for students, mostly high school and college. If you want to compete there, read the rules. Their min sumo is 3 Kg and their heavy weight sumo is 125 pounds.
Rick