The Magic Trackpad "plugger" is a board with a 3.3 volt regulator that's designed to be the exact size of two AA batteries. Its purpose is to allow you to power an Apple Magic Trackpad with a USB connection rather than two AA batteries.
I sell the board in my Tindie store, but it's not a compelling product, as it's not quite complete.
What I envision to complete the product is a replacement for Apple's metal plug with a #6 hole down the middle of it, and a stiff metal spring that can be soldered to the - connector on the board.
The idea is that the USB cable would run up through the middle of the spring and through the hole in the metal plug. You'd insert the board into the battery cavity and then screw the plug in. As the plug was screwed in, it would compress the spring, pressing the + contact at the front of the board into its mate as well as insuring a good contact between the spring and the plug.
I envision the plug being created by Thingiverse out of metal.
But I don't have the 3D modeling skills to create such a thing, nor to spec or obtain the spring.
Can anyone help me out?