Block & Tackle
DIY Snatch Block
Mark Hamill, who you can reach via the
group on Yahoo, designed and build the snatch block below.
UHMW plastic would work well in this design. The block is hot dip
galvanized after it's built. A wood lathe or router with a cove bit
can be used to cut the notch in the pulley. The pulley bolt
is stainless steel as well as the screws that secure the cheeks to
the flat bar. There is an oil impregnated bearing between the
pully's 5.16" bolt and the plastic pulley. Look online or at your
local bearing supply house for these type of bearings.
Bunting Bearings are
two common brands. An Oilite bearing 5/16" ID, 3/8" OD and 3/4" long
will cost less than $1. You can get them online from
www.McMaster.com. Don't try to
machine the ID of these bearings because the pores are easy to seal
with dull tools. Just buy the right size or modify the design
to fit what you find.