Block & Tackle

DIY Snatch Block

Mark Hamill, who you can reach via the OrigamiBoats 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.  Oilite and 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.