[CAD_CAM_EDM_DRO] Problems in Timing Belt drive system in 6WD robot

Something that can be done to relieve the rigidity of the axle is to give
each wheel some freeplay.

Imagine an axle with a pin though it at each end. The wheels on this axle
each have a cut-out so that you could rotate the wheel 350deg before it
hits the pin. If all wheels are fitted in this manner, they will definitely
still be driven, but on a turn, the outer wheel will be able to freely
advance to a degree.

Between all six wheels, although random, it should provide enough relief on
the motors to make turns easier. And I doubt the 'overrun' in a straight
line would be noticeable.

Regards
Roland

On 26 January 2013 22:57, KM6VV <KM6VV@...> wrote:

> **
>
>
> Hi Jon,
>
> Did the ASME 'bot have independent suspension for each wheel? It's been
> pointed out that adding a shim to my center axle probably won't help me
> much.
>
> Have you seen DPA's 'bot spin on concrete? Must have done something
> right! He does have ROAD tires, instead of my OFF-ROAD tires.
>
> Alan KM6VV
>
>
> On 1/26/2013 10:33 AM, Jon Elson wrote:
> > KM6VV wrote:
> >> Sorry for the cross-posting,
> >>
> >> I'm having problems with the timing belt drive system in a 6WD robot I'm
> >> building for Robomagellan competition in the upcoming Robogames.
> >> (Mechanical design courtesy DPA).
> >>
> >>
> > Our ASME student group built a mud competition car some years ago that
> > was 6 wheel drive. It was impossible to turn on hard surfaces, but worked
> > OK on mud. The fix was to put shims on the middle axle, so it rocked
> > slightly
> > front/back or a flat, level surface. This reduced tire pressure on the
> > front and rear axle enough so you could turn it well on pavement.
> >
> > The axles were on pillow blocks bolted to the frame, so it was a
> half-hour
> > fix.
> >
> > Your vehicle has the same problem, lack of a differential between the
> > wheels. Some wheels turn faster than others due to the dynamics of
> > rounding a corner. At the very least, the middle wheels are at a smaller
> > radius of the turn than the front and back.
> >
> > Jon
> >
>
>
>


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