22/03/2008 - Tie downs and bell crank brackets

Time to go back to the main spars as I had picked up 2" plates that will be made into spacers.

I had previously bought a 1" hole saw to make the lightening holes in the middle of each spacer and it made light work of the job in the bench drill.  More waste aluminium the pile is growing !!

The first hole on the tie down bracket is made by drilling 3/16ths hole by the dimensions in the plans and then match drilling using the spar itself.

Now its also worth mentioning I cheated and my Sister bought me pre threaded tie downs from Cleveland tool.  So in the last picture you can see the tie down hooks that come with them already screwed in.  Neat.

So with the bolt holes all drilled to 3/16ths" the next step means putting the nut plates (yes more nut plates) onto the bracket.  They also need countersinking so everything stays flush and flat against the spar web.  Now I pondered on whether to prime these brackets or not; but then settled on an Allocrom 1200 dip for them, so they are protected and gold like the rest of the spar ... well that's the theory anyway.

Rivet together, and bolt together.