Algebra Build 5.2 More Sanding, Again!

All flying tailplane (AFT) now - it's built in two halves. Each half starts off as a block of balsa, glued together from two pieces

It has to be tapered in thickness from the root to the tip:

I used a razor plane, seen to the right of the pictures, to do the main work, then finished off with my trusy Ali-Tube sanding block with 120 grit paper.

After tapering, an aerofoil section has to be sanded into the AFT.

You begin by marking a centre line around the edge of the piece. This is essential as it's really easy to get lost as to where you are.

After getting a rough aerofoil section, the tips are rounded and a new centreline drawn on them

Then these are shaped and final sanding done

The two halves will join either side of the vertical fin, using piano wire joiners which are located in tubes glued into either half of the AFT

It'a really important to get these straight. I lined up the trailing edge of the AFT with a straight line on the building board, then made all my measurements from that.

Slots were cut into the AFT and the barss tubes glued in. The joiner wires are longer than the tubes to allow for the thickness of the fin. I had no wire of equal diameter, so I cut the slots in the AFT over length to allow me to use the joiner wires as jigs to keep the tubes in line.

In the photo below you can see the original end marks for the slots and that I've extended the slots to allow for the extra length of wire.

That's the AFT done. It'll need the slots to be filled with scrap hardwood. I have to build the fuse before that so I can see how much hardwood I have as scrap!

So that's the wings and horizontal stabiliser prepared as far as I can. Final finishing and jigging for these parts will be accomplished when the fuse is built, when I'll be able to do my first test-rig of the aircraft.

Fuselage next, then!