Let's Make Robots!

How to make the perfect "third wheel"

Made a robot with 2 wheels, and need a "coaster", half a tennis ball or something? This must be the best sollution!

I admit I have not tried this, but it just struck me:

You know the kind of robot.. well - like the "start here-project"; You have 2 wheels, and perhaps you need something to drag behind?

Well, the perfect solution would not be half a tennis table ball, or that kind of thing. The perfect would be a little wheel dragged on an open L-shape, a caster.. yes.. but if you do not have a such, this is it: Use a pearl!!

The bigger you can find it, the better, of course. Huge plastic pearl, stick a pin through the hole (perhaps drill it out first), and you have a near perfect caster :) Mount it so that when driving forward, the perl is spinning, and when going to the side, it will slide..

Why on earth did I never think of that before? :D

It does not need to be a pearl, you often get little hard plastic balls that has a hole in them. Little black thingeys, they are mounted on a strings or something to do some stringey-stuff or whatever :) That would be perfect!

I am a collector of hard round objects with holes in them from now on!


PS: No twss in here, I have written it so it cannot work!

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This is also a way to do it.


You know what that robot really needs? Pez.

You are properly sitting on 5 of them right now.


Office chair wheels are perfect ass a drag along wheel´s on bigger robots.

They are easy to find, just go dumpster diving.


Yes, these are "nice".. But they are extremely heavy :) Even the smalest ones are usually made to take a load of a couple of kilos.. Wich is way more than one usually needs.

Making big and heavy robots are easy this way, but then you have the problems with motor controllers for big motors :)

That's how I'd describe a bead.


Google image search "bead" at your own peril!

another choice, for bigger robots, is to go to any hardware store, they sell great caster wheels for furniture. they're often ball-beared and works perfectly.
You can use the ball inside roll-on perfumes!   :D

This is wood, but here is the kind of stuff I was on about: http://www.fredaldous.co.uk/shop-online/wooden-balls.htm