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Unread 08-02-2013, 12:39
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jkessler_22 jkessler_22 is offline
Motor Man
AKA: Joe Kessler
FRC #3015 (Ranger Robotics)
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Join Date: Jan 2008
Rookie Year: 2000
Location: Spencerport, NY
Posts: 11
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Re: Plaction wheel shooter?

Quote:
Originally Posted by ksafin View Post
Where exactly did you add the weights?

When you say opening across from the valve stem, does that mean on top of the hub, or in between the spokes?
We placed them between the plastic spokes. The opening was fairly generous for the size of the weights. The weights I had were about 0.75" x 1.0 " and weighed 0.5 oz each. I cut one in half, stuck it to the top of another full 0.5 oz weight, then put them between the spokes.

To determine how far out of balance they were initially, we put an 8 mm shaft through our hub and supported it with two metal 12 inch rulers on edge. If we rotated the tire so that the valve was 'up', it quickly spun so that the valve was 'down'. We added one 0.5 oz weight, which made it spin much more slowly, but still settled into a valve 'down' position. We played with the amount of weight to find a point where the wheel could be placed in virtually any rotational position and it would stay there. That weight came out to be a total of 0.75 oz in our case, but could differ depending on what wheel/tire combination you are using.

The decrease in vibration was dramatic when we were done.