Finalizing the tail surfaces installation

Once all the tail surfaces were in place, I made initial measurements with a smart level as well as a conventional level to know how far I was from the desired 2 degrees of incidence on the stab as well as zero washout as suggested by Doug Sowder's article on Pitts rigging. I was quite happy to find that without any tension on the tail wires, I was very close to the target incidence, with a little washout on both sides.

I used a tool that my friend Paul Goyette and I made for tensioning the wires. It is similar to the one that Steen sells, but made out of nylon and with a cylindrical shape rather than cubical. I think this home made tool is even less prone to damaging the wires than aluminium and would also cause less damage should I mistakenly drop it on fabric. I have two of them, one for the tail and one for the wings.

I slowly increased the tension by adding 1/2 turn on all wires, measuring angles and repeating until getting in the middle of the target range of 250 to 325 lbf tension. As I approached the final tension I realized I was inducing anhedral to the stab by doing 1/2 turns everywhere at each iteration. This is probably due to the top wires being longer and therefore stretching more that the bottom wires. When I realized that, I did one round of tensioning the top wires only, which brought me back to zero dihedral.

I used the Holloway Engineering tool along with an electronic torque wrench to measure the tension. 

Thanks to my girlfriend Isabelle who helped during the final stage of the tail installation!