OK …. First step ... I need to reduce the shaft angle.

Graupner “U” joint or wire drive.

Option 1
Graupner “U” Joint:
I can slam the stuffing tube down to the keel and drive the solid shaft internally with the “U” joint. The drive angle won’t be zero but it will be significantly less than 5.5 degrees. The “U” joint has 2 ball things, 2 shaft couplers and a central section. I ‘m guessing it could be used externally in a strudder application, but it’s looks pretty draggy. Will there be an issue with the @6 degree bend?

Option 2
Wire Drive:
My preference, but I don’t think I have access to the key material. I’ve access to a lathe and can add 1/8 shafts to both end of the wire. I’ve got brass tubing in the required sizes. But music wire is a problem.

Welding rod is widely available … can this be a substitute? I fly gliders and I’ve been forced to use welding rod for my push rods. There’s an aluminum rod that’s very soft, I use it as a servo saver linkage …. it bends before damage to gears etc. Then there’s this brassy looking rod … it’s quite stiff but it fatigues easily … you can’t do multiple bends at the same point it’ll snap.

I did a mock-up with the brassy looking rod and it’s surprisingly smooth over a 5-degree bend. My fear it’ll snap after a few runs.

Why don’t people sell wire in small quantities?

Anyway suggestions welcome.