Actually cut (and bent, and soldered) some metal!
I'm going to do Walker-style tweakable flaps, which means that you need individual flap horns. This, in turn, means that the flap horns need to be accurate and stout.
So the flap horns are bent from 1/8" music wire so that -- hopefully at least -- they won't get tweaked by accident. Rather than just soldering the wire to a hole in the horn, I bent the wire itself, to give the horn more surface area and far more moment arm to work on the wire. They've got two hinge tubes on each wire so I can space the hinge tubes as far apart as possible for rigidity. The top two pictures show the result.
I was concerned about getting all the angles right -- the control arms need to be perpendicular to the plane of the flap arms, even while being offset about an inch and a half. Rather than try to get it all right "floating on air", I made a jig from a bit of 2x4. The jig holds everything in alignment while I'm soldering it all together.
When I get to the point of making the control rods, there'll be a single rod from the bellcrank to the flap control hole on the left horn, and a rod from the left horn back to the elevator. There'll be a boss on the elevator rod with a screw going to the right flap, set up so that turning the screw tweaks the right flap with respect to the left flap & elevator. Alan Resinger has an excellent picture somewhere around here showing how he did his -- I'll be copying that. The only thing that (to my knowledge) I'm really doing different from Alan and Paul is that they put their adjustment on the left, where mine is on the right because I'll be running a muffled slimer, and I don't like the thought of all that oil dribbling inside my nice clean fuselage.
Done right there should be a discrete little hole behind the right wing into which I can reach with a nice long ball-end hex driver and adjust the flaps.