On Sun, 11 Mar 2012 05:01:46 -0400, "Wild_Bill"
wrote:
There are round polyurethane belting products available for using as
replacements for light/medium V-belts.
The recommended pulley sizes are possibly being stated for power
transmission, as in round belting in a V-belt pulley groove needs a minimum
surface contact area to transfer a certain amount of power (definite
maybe).. and V-belts exhibit nearly full surface contact in V-pulleys.
Since you're not wanting to use a round rubbery product for delivering
power, I believe you can disregard those recommendations, within reason (not
trying to run a fat belt around a tiny wheel).
The urethane product I'm familiar with is supplied on spools so any length
of belt can be fabricated.
There was a "special" heating tool.. a fairly large soldering iron with a
thin flat plate mounted as a tip.
The belting would be cut slightly shorter than the circumference of the
V-belt it was to replace.
The ends need to be cut squarely, then placed into a small jig/fixture to
hold the ends in proper axial alignment and the hot flat tip of the iron was
used to heat both ends simultaneously.
When the ends showed sufficient melting was taking place, the iron was
pulled out and the ends were jammed together until the joint cooled..
plastic welding basically, very similar to bandsaw blade welding.
The nicest splicer I've used held the belt ends in alignment in a
pliers-like arrangement while a radiant heater between the ends warmed
them up. When the ends swelled indicating proper temperature, you
squeezed the handles, which caused the heater to snap out of the way
before bringing the ends together. I don't remember the brand, nor
have I ever seen another. The radianat heater seemed to do a better
job and require less skill than the hot paddle type.
For prototype work, I weld the stuff with a heat gun, vee block to
hold alignment, and a scotch-bright deburring wheel to remove the
flash.
This is the best place I've found for welded to order urethane belts,
as well as belt stock in various diameters and durometers.
http://www.pyramidbelts.com/
WB: It occurred to me as I was about to send this; I think there was a
belt I made out of urethane air tubing on that engraver I sold you.
--
Ned Simmons