26 Sep
2009
26 Sep
'09
3:36 p.m.
On Sep 25, 2009, at 6:10 AM, Sridhar Ayengar wrote:
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.
I'd always been given to understand that the reason for the taper in
train wheel profiles is to facilitate travel on curves; i.e. the
wheels on the inside edge of a curve travel on the smaller diameter
of the taper and the ones on the outside, the larger. Saves a lot of
flange-banging.
--Chuck