26 Sep
2009
26 Sep
'09
2:33 p.m.
On Sep 25, 2009, at 6:10 AM, Sridhar Ayengar 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.
Umm. Wow. It never occurred to me to think of the capstan riding
in the belt rather than the belt riding on the capstan.
-Dave
--
Dave McGuire
Port Charlotte, FL
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.