SumoBot modification

MyBot

Hello guys,

I'm modifying SumoBot kits to take part in 1kg (2.2 lbs) Sumo Robot contest. I'm using four servos (default Futaba continuous rotation servo) for the sumobot (with custom designed chassis). I'm also combining each two servos in a single pin because of the limited pin on the PCB (default SumoBot Board with surface-mounted BS2).

The problem is:-
1) How much power do the four servos needed? Can I give 9 or 12V for the servos? Right now I'm using only four AA Alkaline Batteries (6V) as the power supply because I've read in somewhere that giving power more than 6V will damage most servos. Is it true?

2) How to avoid the IR object detectors from becoming "blind" if they encounter an inclined reflecting surface?

I'm still in progress making the robot and this is my first time roboting. Sorry for troubling you guys.
Thanks.

Mike Green

1) Servos need a source of power with a voltage roughly between 5V and 7V and peak currents of 1-1.5A per servo with average currents somewhat less than that. DO NOT try to run servos off 9V (or 12V). You'll destroy them.

2) There's not much you can do about inclined reflecting surfaces. Most distance sensors use IR or ultrasound and an inclined surface will reflect both. You'll get a little reflection back from the surface itself, but it would be non-trivial to tease that out of the return signal.

Chris Savage

Hello,

I would also like to point out that due to variations between servos, and especially on a modified continuous rotation servo, it is likely that if you’re pulsing them from the same pin you may actually end up causing some minor binding between wheels on a given side. If you used different pins you could at least tweak the constants to prevent this. Take care.

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Chris Savage
Parallax Tech Support