Dan, the videos you posted were great. It's kinda funny how both you and I stopped the instructions at the same point. However, anyone making a video (or anyone wanting to use the mechanical triggers) is definitely urged to go look at the trigger assembly post.
The trigger assembly post, however, covers only assembling the triggers themselves. It doesn't cover hooking up the cables to the brake lever, or attaching the triggers to the camera supports.
Some things to keep in mind that your video should show:
1. Put your cameras on the camera supports without the triggers first, and in non-paperback mode.
2. Put a sample book in the cradle and lift the book up to the glass.
3. Adjust the camera so that the page is centered left-to-right in the viewscreen. Tighten the camera down.
4. Now you can take one trigger and position it so that the tip of the finger touches the button. The trigger might work best on one side or the other side of the camera, it doesn't really matter. Also, even if the cable has to make a somewhat tight turn, it shouldn't matter that much. Bicycle cables are typically teflon-coated on the inside, so they're very slippery.
5. Before you permanently attach the trigger, take one of the felt dots and put it on the end of the finger. You might even want to take some scissors and cut the felt dot down a bit so that it fits right on the camera button. Glue the felt dot to the end of the finger.
6. When the glue is dry, position the trigger again, and here's the hard part: drill two countersunk holes from the bottom of the camera support into the trigger. You will have to drill them so that you avoid the cable
. It's also a bit difficult to position the holes, since there's not much to visually tell you where the holes should go. I managed fairly well by taking a small ruler, determining the position of the trigger relative to the edge of the support, adding about half the width of the trigger, and transferring that measurement to the underside. Taking a pen and going around the outside of the trigger on the top side also helps you position the trigger in the right place again in case it moves.
7. Attach the brake lever to the book scanner handle. You'll need an allen wrench to tighten the machine screws.
8. Fit the nub thing on end of the cable into the brake lever. I found that it just sort of hangs in there, with no support. You will then need to use a cable clamp for each cable and locate a place on the handle plate (I forget what Dan called it) to clamp down the cable.
9. Use a small bungee cord and wrap it around the camera support and the small end of the trigger finger (the end opposite the camera). This causes the finger to rise up, pulling on the cable.
10. Squeeze the brake lever and watch the action. You will need to adjust the trigger side of the cable so that the finger lies just above the button when you're not squeezing. That way, it will only require a little squeeze to trigger the cameras.
11. You're done. Dance like nobody's watching.