Motor contained in wheel?

Franklin

I have an idea for a bot but I need the wheels to piviot 270 degrees (maybe less) on their contact point so I am thinking if I can have the motor in the wheel hub that would be nice. Does anyone have an idea for a small scale (6 inch wheel probably), simple, not too expensive approach to this problem or links to places I might get something like this?

Thanks,

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- Stephen

Timmoore

This is a bit on the pricy side but may give you some ideas http://www.andymark.biz/swervemodules.html

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Spiral_72

I made one recently for a three wheeled bot. The front wheel was driven / steered. While driving a single front wheel didn't work well for me, the steering worked pretty dang good.

I whipped up a drawing of what I made.... Let me know if you want more details. I don't have a picture, sorry.


I used 3/4" MDF for the bot base and sunk a standard RC positioning servo in the bottom for steering. Then I made this L-shaped bracket of MDF that housed a continuous rotation servo directly driving the wheel hub. There was a small ball bearing in there as well. I don't remember how I made the coupling....

I used a relatively small 2.5" DIA wheel.... if you use a 6" wheel of any width at all ya' probably would do good to use a thrust bearing of some kind to support the whole assembly onto the base. Ace hardware has some tiny lazy-susans for cheap that I've used in the past. They were surprisingly tight tolerance and smooth for the cost.


While I'll bet you want something a little more fantastic than MDF and RC servos, the concept is still the same.

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"puff"...... Smile, there went another one.

erco

Spiral: Heathkit just barely beat you to market: their 1980's vintage HERO & Hero Jr. robots! 3-wheel bots, 2 passive wheels, one powered & steered wheel. HERO was front wheel drive, and the later Jr. version was rear wheel drive since they found that was more controllable.

The steering wheel turned 180 degrees; +/-90 degrees from the center (straight ahead) position. But only had limit switches on the two outside extremes. Its stepper steering motor assumed that the center (straight ahead) position was halfway between the two limits. It was often wrong, and trying to drive the robot straight was usually a maddening experience.

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·"If you build it, they will come."