Let's Make Robots!

Pudding Bowl Special

Rolls about under microprocessor control. Avoids obstacles.

Having taken a sabbatical from programming Big Chaser, I decided to do a ball bot.

PuddingBowl_01_.jpgThere are a pair of pudding bowls or mixing bowls attached directly onto a threaded bar. Also attached to this bar is a servo (modified for continuous rotation). When the servo is powered, it moves the bar, attempting to turn it and the pudding bowls.

PuddingBowl_02_.jpgHanging from and perpendicular to this servo is an unmodified servo, attached to which is the battery and the control. When this second servo moves, it swings the battery etc (the "weight") to either side, causing the ball to steer.

PuddingBowl_03_.jpgWhen the main servo is powered, it causes the battery to attempt to "rotate" around the bar, which it cannot do, so the ball rolls forward.

PuddingBowl_04_.jpgWhen the microcontroller detects a current over a certain amount, it assumes the ball has hit an obstacle and attempts a three-point-turn.

PuddingBowl_05.jpgYes, clearly the device is not yet under microprocessor control. In fact, you can hear me twanging the radio control joysticks in the background, but what's written here is a goal.

I wanted the "ball" to be as near spherical as possible so I cut the rims off the bowls. Of course this was what had given them their strength. After several attempts, I came up with the idea of making interlocking teeth on the edges of the bowls and that's what I'm trying next.

This is a bunch of photos and videos of the gubbins being assembled and working. I don't know if I'll do much more with it, now. I've sort of demonstrated the principle.


I'm getting all fired up about the mark II. Look what my wife decided to throw out:



That's gonna be far more managable than the two pudding bowls!!

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Yes, that woud have been better. My main problem was the seam bewteen the two bowls. I didn't even know large hampster balls existed. If I can find a more spherical shell of some sort I will ressurect this project.
The biggest I found are 13 inches in diameter, they're like 5 bucks on eBay.

I'm thinking about making a robot inside a hampster ball with omni wheels, based on this:


warning: site has inappropriate content

13" is the biggest I could find too.

When I went to school, 13 inches was quite a lot. (Haaarrr, haaaarrr!) Now, filth aside, I wouldn't bother with the hamster ball at all. Just go with the omni wheels. I like the orientation of the wheels in the cartoon: the axles wold be perpendicular to the side of teh 'bot. That's quite unusual. It would work perfectly, though.

Wuss around in stainless steel kitchen gear!


I know: still not a full sphere. That's a real shame...


At least in metal I could batter it into shape.
Love it! Waiting for video with globe when modification finished :D

My God,

you've destroyed the earth to create your next robot !

A little backwards don't you think? Normally you create a robot to destroy the earth!
I was surprised at how hollow the world was.