Whats Happening ?

Heavy jigsaw puzzles

Trevor and Adrian begin to assemble the winding mechanism required to raise and lower the ground paddles.  Because the ground paddles are much heavier than those in the gates they decide to incorporate a reduction drive.  Modifying the mechanism means that the main winding shaft which connects with the rack has to have one end shortened and ground down from a taper to a square.

Having assembled the various cogs and the rack and bolted it down loosely everything appears to work well.  When the bolts are turned down tight nothing moves so something is obviously out of alignment and much head scratching ensues.