Cheap, Surplus Attitude Indicators??

[gnx99]

Hey,
I'm looking for a cheap (<$20), old, beat-up, electric attitude indicator to play around with and use with students. I figure I can wire up a few 9volt batteries and a switch.

I've checked eBay, but not much luck, any ideas?

 

[EagleRJ]

You probably won't have any luck finding modern style AIs that you can pick up for cheap. Any that are red tagged (unairworthy) are usually destroyed by the mechanic to make sure they don't wind up on another airplane.
Your best bet is to find a surplus military AI. The gyro is essentially the same. Try aircraft salvage yards, flea markets, and long-time airport residents who have a lot of old stuff piled around. Only downside is, it's likely to be a pneumatic gyro, so you can't make it run.

 

[flywithastick]

I picked up some instruments a couple of years ago for the same purpose. Got a mil surplus DG (believe it's US Navy) with autopilot or similar electronics inside. I haven't even tried to power it up since I thought it probably used 400 cycle ac power. Could be rectified inside, but haven't looked closely enough to see. Also got a ~50 yr old vacuum horizon, altimeter & airspeed. Would really like a VOR CDI, but haven't found one yet.

The price was right - all free. Check at some of the aircraft surplus or salvalge operations. That's where I got my stuff.

 

[EagleRJ]

Showing students the inside of a gyro has kind of a "gee whiz" effect, but showing them all the componants is about all you can do. Even then, it can be confusing for them, with all the parts.

You can put on a much more practical demonstration with a gyroscope from a science or toy store. You can demonstrate precession and rigidity in space to the student, and the only power source you need is the length of string!

 

[flywithastick]

Showing students the inside of a gyro has kind of a "gee whiz" effect...

That's exactly why I show my student these things. So they can say they've seen what they look like inside. We don't strip them down to nuts & bolts and reassemble them. I pull the covers off, show the guts, spin the little gyro with my finger, show how the mechanism moves the indicators and put it back together. Takes about 5 mins or so.

I don't know how the talk about powering these things up came about. I never tried and don't really care to. Mine are static display only.

The toy gyro idea is good. I'll probably get one next time I'm in a toy store.

 

[gnx99]

I did see some 5" british military surplus (28volt) ones on a website for $225. But i guess a toy gyro would work too.

 

[RJones]

I have an old vacuum attitude indicator from a Decathlon. A simple vacuum source is all you need. I've hooked up a vacuum cleaner to it and it worked just fine, spooled up and did its thing. The case is part of the operation of the gyro so you wouldn't be able to see the gyro spinning. I have no use for it, has no tags, not airworthy...yours if you want it, just pay the shipping.

RJ