Shaping Sheaves

In preparation for spar sanding, I decided to cut the openings for the mast sheaves. I pulled the Delrin sheaves from a pair of old Schaefer blocks I found in the shed (don't know what boat they came from). Both are approximately 3/16" short of the mast tips and will work just fine for the halyards.

spar and drill press on bench.

successive borings.

   

Sheave test fit.

I jigged the spars level on the open bench, chocked them in place, and bore holes for the sheave slots. A Forstner bit did quick work of it.

















A chisel and utility knife roughed the edges to shape. Filing completed the needed slot width.

I test fit the sheave with a pan  head machine screw. I'll replace with a counter sink screw and finish washer later. he machine screw may be tight enough to fore go an aircraft nut on it.