Howdy,
On Sun, 14 Dec 2003, Steven W. Reilly wrote:
> One person referenced a ON-car balancing rig. This got me thinking of
> another way to make my "bubble balancer. Instead, I would create a
> "spindle" which precisely matches the hub-centric wheels. The spindle
> would be of 1" threaded rod. There would be a machined hub against which
> the wheels would fit.The wheel would be held on the hub by a threaded
> nut/large washer against the hub. The hub would be tightened down to the
> threaded rod. At each end of the spindle would be small bearings that
> would sit in a v-groove on a level stand. If the wheel was heavier on one
> side and it was spun, I would imagine that the heavier spot would usually
> rest at the bottom if the bearings are "free" enough.
>
> Problem with that idea? Perhaps I wouldn't be able to get the clearances
> tight enough for the threaded portions. Dynamic balance not achieved.
I'm not completely sure I'm reading you correctly above, but it sounds
like what the MC tire busters used back when I was racing bikes.
Basically you just have a U shaped stand that has two bearing on each leg
of the U at the top. Then a rod goes through the wheel, riding in the
bearings, suspending the tire vertically. The heavy side is down. Let
the wheel settle, mark it for reference, then offset it and see if it
settles in the same place. Put on some weight, try again, you're done
when the wheel stays wherever you set it.
For the "rod goes through the wheel" part... I think I'd make a cone for
one side and a bowl shape for the other. Thread one side of the rod, fix
the cone to a stop on the other side, then thread on the bowl, pressing
the wheel up against the cone. If you have lug-centric wheels (unlikely
with anything modern though), just make a hub with that lug pattern, etc.
Should do a static balance as well as anything else would, easy to use,
etc.
Mark
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