Mechanical airball

Here's a crazy idea that I invite any of you crazy folks out there to try.

So the trick with cockpit displays is ... brightness. And this makes it hard to make a general purpose HUD, because you need to collimate a super duper bright, yet high resolution, display, and super-impose that against the background. But mechanical things don't have that problem. And in fact, with tiny motors and microcontrollers, we can actuate mechanical things pretty easily. Could we build a subset of the Airball visualization by mechanical means alone, and put that in the pilot's field of view?

To get our minds thinking, consider the following:

The instrument is basically a small rectangle of Plexiglas with a physical circle behind it. The circle can contain an RGB LED so it can change color and brightness with airspeed, or it can be a chunk of some material. Two "cables" (really, tiny pieces of fishing line) hold it up from above, and these are either themselves elastic, or the slack is taken up by some spring or rubber band or something. Two other "cables" (more fishing line) hold it from below, and a microcontroller controls their lengths so as to put the ball in any (X, Y) position you ask it to.

Now, if this can be actuated "quickly" so its response time is "live", sort of like a real windsock, then it can replace or augment an Airball display in the panel.

I'd probably use it to augment an Airball display -- because the Airball display receives raw AoA and yaw values, etc., and contains the "settings" that determine what is stall, what is best climb rate, what is best climb angle, etc. Then it can send simple commands to the mechanical device to go to (X, Y) coordinates based on the fixed mechanical fidicials printed on the Plexiglas. And it can tell the device what color to flash the RGB LED (if installed) for the specified airspeed.

Alternatively, all you want is one-time "programming" of the set-points for a given airplane, so it can be standalone. Maybe you program it using some sort of app, and a USB or serial connection, during a test flight, and then you set it running.

Think about it! I probably don't have time to build it, at least at the moment, but if you're interested, it should be a cool little gadget to make! If I can help you make it, let me know!