25 Sep
2009
25 Sep
'09
3:10 a.m.
Dave McGuire wrote:
On Sep 24, 2009, at 5:11 PM, Tony Duell wrote:
It's called "crowning" here too. How in blazes does that work? I've
always wondered about it.
The same way train wheels work. Train wheels are of slightly smaller
diameter to the outside edge than they are on the inside edge. Makes
the train sit between the rails rather than on them. Along the same
lines, the capstan sits in the middle of the belt instead of on both
outer edges.
Peace... Sridhar
matter.
The ones that we got drawings for and had duplicated were
worked from aluminum stock with quite a few processes to harden them and
form the drive surface so as not to eat the drive belt. The shape of
the pulley causes the drive belt to ride in the center when properly
done, there are no "edges" to retain it. If you have or can get
Known as 'crowning', at least over here.
It's surping the first time you see it, but the pulley is smaller in
diameter at the edges than in the mdidle. The belt runs on the largest
diameter part -- and mves itself there when the pulleys turn. If you
naively make a pulley with a smaller diamter in the middle (with the idea
being that he larger diameter edges will keep the belt in place), the
belt will fly off.