Step 8: Attach Power to the Wings
Now we need to figure out WHERE to put the pistons on the wings.
To do this, you need to measure the exact throw of the piston (how far it opens) and the length of it.
You can also do some math to figure out the chord length of a circle, or you can do what I did and use the old Version 1.0 Eyeball.
We'll use my 4" pistons as the example here, since they have been installed and used at least twice and worked well.
I originally wanted to use pulleys, and/or mount the piston on the backing board. This means that you need to have a ton of nuts and washers to get everything in the same plane, and even then, any variation cause the wings to tear themselves away from the wood. It's just too picky using this method. We will deal with board-mounted pistons in V2.0.
It's MUCH easier to mount the pistons on the wings themselves. This way they fold and unfold without pulling or pushing against anything other than themselves. This was a much more stable solution and the wings worked well for over a year until I took them apart for V2.0.
Measure the piston from center of mounting hole to center of mounting hole. Mark this on a piece of wood (I used a piece of trim from the prototype). Also mark the same holes with the piston open on the same piece of wood so you have a measuring stick with both distances on it.
The piston throws 4 inches, so we know the best place to mount them is somewhere NEAR 2 inches from the highest pivot point.
Fold the wings closed completely, and mark with a pencil the spot about 2 inches from the top pivot point. This is in the middle of the 'wrist' part of the wing. See where this puts the bottom of the piston. Mark this spot as well.
Now open the wings, until the first mark moves completely from the closed distance to the open distance you have marked on the stick. This is where things get subjective, because the requirements for the open position depend on personal taste. Some people like the wings completely snapped. I liked them for this costume just over horizontal.
If the wings don't open quite enough, for you, erase the marks, fold the wings and start again, moving the top of the piston slightly closer to the first wrist pivot, until you have the effect you desire.
For durability, and to prevent the wings from warping, you want the pistons to be pushing in the same plane with everything else. Since the tubing is highly unlikely to be the exact width of the pistons, you will need to use the long 4" bolts and a series of nuts and washers to make the piston as close to straight as possible. Tighten down the mounting bolts with washers and nuts first, then start adding nuts and washers until the piston is as flat as possible in relation to the wings. The piston is going to push against this bolt, which is why I recommend the 1/4", it's going to take the most stress in the whole system.