thru hull backing plate

thingiverse

This allows you to put a 29 mm thru hull block( Harken brand ) on the hull of a boat and pass a rope thew it .inside the hull the rope can travel thru a 1.5 inch hose to another such device allowing for a water tight system .Its nice having a under deck line that allows no water into the hull of the boat and no air to escape should the boat be taking on water . I designed it and later made corrections and improvements. the first 29 down loads have a slight mistake that can be fixed with filing ive since corrected things the thru hull block is bought from Harken a small line travels in to the hull with the help of the block and then in a switch back fashion makes a secondary turn around the printed pully and out the hose barb . Im using 4 of them on my slipper 17 traveler system so far works great and seems water tight the rope gets a little wet in the hose so i am to add a t fitting and drain to the hose soon . I use ceramic bearings in the block to prevent rust 4 of them can be pressed into the pully . the inner diameter of the pulley is 8 mm diameter and a 90 mm long 8 mm bolt will do . two number 10 by 24 bolts go thru the Harken 29 mm block into the hull 10 by 24 nuts go in the printed part to alow the part and the block to sandwich the hull.