The smaller diameter (20 to 30mm) ball bearing sailboat blocks are $15
to $25 as I previously posted. Here is a slick block from REI for
rigging ropes up to 15mm.
http://www.rei.com/product/807414/camp-usa-large-mobile-pulley-ball-bearings
5600# break strength so WLL at 25% is 1400#.
the side cheeks swivel so it works as a snatch block for engaging a
standing line. Does more with ball bearings and costs much less and
weighs a fraction of sailboat or commercial snatch blocks. A shorter
length allows more travel before getting two blocked, helpful on gin
pole and derrick rigging. There is also a double version.
The type of rope matters, check out New England Ropes. I hope their new
owners don't screw them up, they were the best.
http://www.neropes.com/Interim%20Page%20Alternate.html now
www.teufelberger.com/
Generally, double braid dacron or dacron/polyester is all purpose for
hams - UV resistant, very low stretch, doesn't put twist into pulling
cables or antenna wires, ok for temporary guys (NEVER use nylon!), good
for climbing and rigging, good wear and fatigue resistance, but not as a
fall protection line where stretch is needed to reduce the shock load
(eg use nylon or special purpose lines).
Grant KZ1W
On 9/2/2014 3:30 PM, Richard (Rick) Karlquist wrote:
Maybe someone can help me here. The problem
I am having with pulleys is that they appear
to add a significant amount of friction. I
am not sure if it is in the bearing, or the
pulley is too small in diameter, or maybe the
rope diameter doesn't exactly match the
half round surface of the pulley. I see that
rock climbing pulleys are only 2 inches, like
there is no need for anything larger. If I
get one of these super duper pulleys, is my
friction going to magically go away? Does the
type of rope matter in this regard?
Rick N6RK
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