Tuesday, 5 May 2009

A new set of aileron hinges

One of the common maintenance issues with Taylorcrafts is th onset of wear in the aileron hinges caused by the hinge rotating against the clevis pin. This is often noticable on the outer hinges and can be checked by pushing the aileron up at the tip; you will feel the movement on the hinge, it's fairly obvious. A small amount of wear is acceptable but as mine are worn to a point where they are only just acceptable I've been on the lookout for a new set of hinges.

Initially I approached the Factory but due to complications regarding the export of stock oversees, and the fact I discovered that I had Rob's jig for the job, I decided that it would be just as easy to make a new set. The jig, in two parts forms the basic shape of the hinge and allows the mounting and pivit holes to be drilled and reemed.

The basic set of six hinges took a weekend to make using the jig and some 0.050" 4130 steel sheet.

1) Six oversize blanks were cut from the sheet steel. The size is sufficient that each piece fits snuggly in the jig ready for pressing.

2) The basic shape is pressed using a vice.

3) While still in the jig, the mounting and pivit holes are drilled and reamed.

4) The blanks are roughly shaped (original hinge shown for comparrison).

5) Final finishing with file and wet/dry paper and comparrison with an original hinge.

6) The final modification is to spot weld a tab onto the hinge to provide a flat. Each clevis pin will have a flat filed to fit thus preventing the pin from turning against the hinge.

Lastly, my thanks must go to Rob Lees and David Nowill, who between them, designed and manufactored the jig, and then let me use it.

Finishing the Ailerons

I have finally gotten two refurbished ailerons, but before I put them to one side, I wanted to check that everything fits in relation to the wings. I'm basically using the wings as a jig to check the alignment of the ailerons with the new hinges.

The port aileron fits without a hitch but the alignment on the butt rib of the starboard aileron is out for some reason and of course I've no photograph to check the alignment prior to the rebuild.

The extent to which the but rib is out of alignment can be gauged by looking at this photo, about 1 cm at the trailing edge.

To rectify this, I've used a piece of trailing edge, cut down so that it forms a box section that will fit inside the existing trailing edge when it is cut.

After riviting, I will fill the gap with micro balloon filler so that the repair will be less obvious. The rivit heads will be visible because they couldn't be countersunk but tey are no worse than screw heads used all along the trailing edge.

I've checked the fit after the repair which gives a much better fit now with the wing. The ailerons will now be put aside, uncovered, until I come to rig the aircraft way in the future.

Now back to the fuselage and a lot of welding work....