Quote:
Originally Posted by Mr_I
We are very tempted to use the 6WD base that came in the kit of parts (simplicity, cost, agility, it's here now, etc.). The KoP frame, however, only powers the center wheel. I understand that a bot built this way can work (since the center wheel is hopefully always touching the carpet), but we're wondering about powering all the wheels.
Is working the details of chaining all six wheels worth the effort? Will powering only the center wheels put us at a disadvantage (pushing, for example)?
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Yup. In a perfect world, your weight (or normal force) is perfectly divided between each contact point with the floor. So a 6 wheeled robot has 25 pounds of downforce one each wheel. You only convert that normal force into tractive pushing force if that wheel is powered -- otherwise you might as well just stick a caster there.
(Imagine you have a really heavy piano. If you put it on unpowered wheels, it is easy to move.
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Ie, a 6 wheeled robot (in a perfect world) with 4 unpowered wheels gets 1/3 the pushing of a robot with 6 powered wheels. If you do the dropped center wheel, then its likely 1/2, since typically only 4 wheels are on the ground at any given time.