Algebra Build 2

Sooooooo...

I glued-up the wing tube boxes. The cutting of the wood didn't seem all that accurate but I guessed they knew what they were doing. 

Then came the big moment - marking up and cutting the wings.

The thin slots for the long spars were already cut, so I just had to cut the wider slots for the actual boxes.

As I was cutting out the slots, it occurred to me that there was no way of jigging the assemly to get the wings straight and level - good thing I made my building board nice and 'true'.

I found some brass tubing which, with a little shimming, was just the right size to fit into the wing joiner tubes. I then figured that if the wings were held flat on the building board, with the trailing edges straight, the tubes would hold the joiner tubes in line with each other - so the wings would not have different incidences when assembled. Here's what I came up with:

1) Completed wing boxes with temporary joiner tubes

2) Joiner tubes made from brass tubing with aluminium tape to shim them:

3) Test assembly on the bench:

... there's a straight batten keeping the trailing edge in line.

4) Glueing up:

The idea was that, with the wing held flat to the bench and the tempoaray joiner tubes holding the wing sockets in line, the result would be a nice straight and true assembly.

Unfortunately it didn't work - one of the joiner tubes in the wing was much higher than the other, resulting in the 'twist' between the two wings. Hmm.

See next installment for the cure! 

Cheers for now,

Roger.