This is my version of (at least) the base of an RFL upright robot. It works pretty well, but I can't go much further until I get my hands on one of those RFL Football Robots.

Then, I'm going to want to make my RFL Robot Base into the most powerful line backer or maybe Center in the RFL... Geez, maybe the "Super Bowl?"

Wait a minute. They use like a 9-Volt battery pack and a fancy gearmotor on each wheel...

OK then. This bot will make a nice coach bot, or cheerBot... Maybe just half-time entertainment?

Geez.

Making an upright robot presents some interesting challenges. Of course we could use a gyro mechanism, but that wouldn't permit such a low price.

The issues have to do with the dynamic part of the robot, you know where it starts, stops, turns and so on. Where gravity pulls with no mercy as to our checkbook. And this is where things get tricky.

When you apply power to the wheels, they move right along, but the first thing that happens is the center of gravity shifts. Oh No!

The bot builder has to compensate and in the RFL Robot, this is done with extra wheels, sitting in front and back of the two drive wheels. Now you get the advantages of the quick turns and fast stops and starts and all that stuff that makes a good football player.

By restricting the distance the motor moves the body in relation to the drive wheels. We can keep the center of gravity within bounds.

This is the first crack at limiting the COG. By putting a small frame on one side, using a bunch of spacers hooked together with little wheels, I get the same effect as the RFL robot.

For the back. I bent a hook from a paper clip. For moving forward, the bot can lean on the clip. Moving forward, it leans against the small wheels. Since I didn't have fancy wheels yet, I used wheels from a Track Bot (leftovers). For the small forward wheels, I used some plastic gears leftover from building the Twin Motor Drive.

Putting the batteries in place was a real balancing act. The batteries would end up having to be pretty much at the center of the bot's body.

I started out in general experimenting with mounting motors in various configurations. This video shows how the experiments began with a battery taped on, and wires twisted together.

I was trying to figure out the optimum way to distribute weight on a small robot. That led to standing the motor drive vertically. That led me right back to the RFL Robot Football League Robots.

Now I use the frame to strap on a picAxe 18x with Motor Controller. Now's our chance to put some juice to the machine.

Putting the picAxe 18x plus motor drive (same one as in dogbot) would be the bees knees... Except for one thing... The power! Oh the power! I used a simple turn right, turn left kind of approach for the initial testing and with one motor, then the other running, each would dig-in to the carpet, not really run along it...

Let's dig into the software and see what we can do to make our bot civilized, using it's brains to direct it's brawn....

The wheels came in the mail, they just push right on to the twin motor gearbox... I've got things taped and wired together, just to be sure this whole idea will work...

I stuck an IR detector at the top of this configuration in hopes of giving this thing some ability to navigate collisions with objects...

These are seeming to be disasters... I got the new wheels, they provide better traction, but now the upright bot has falling over issues when it jumps forward or backward...

I figured I'd have to readjust things a bit... Then I got myself a handful of these grounding straps... These things are easy to bend and that allows me to clean up the design by bending brackets for the "shoulder pads." Now the batteries transfer their weight to the wheels by virtue of angled brackets that attach to the screws that hold the motor-body together. This works well...

Stand back RFL "Bots" My little critter will at least make a great cheerleader robot!

If we were using a set of sensors, we'd want to know when the slightest tilt occurred and we would move the bot against the pulls of shifting centers of gravity. But when we stop, we are still moving, jiggling a little as it were. And the way we stand up is by moving.

RFL bots are supposed to stop when and where the action goes. It seems the guys at RFL knew this and built a bot to work well in games. When the action stops the robots stop. All the action stops in place and it gives the RFL Robot a chance to compete.

So the low-cost uprighting system in the RFL bot seems to be the way to "play the game," so to speak.

So we learned the battery position by playing around with the format. And you can see the 4-pack battery on top of the Motor Assembly.