It will still freewheel but just a lot slower. But I still don't like the idea of shorting the leads. It's basically shorting out a DC generator which will heat up the windings. Don't know how much. May not even be enough to worry about. Still, the idea of wasting the generated electricity just goes against the grain :>)
Tracy
At Western Electric the release of the precious high pressure smoke from a number of electrical devices was a daily occurrence. There were some recreational releases as well as the regular testing releases.
There were also trip wires and booby traps set up for third shift testers who would climb over the wire and barrow our shipping punches so they could pre-punch IBM cards and ship product that had not been tested.
The production numbers can be real high when no testing is required.
With hundreds of cables running all over the floor, it was difficult to tell when one of the aluminum desks was connected to a 5,000 volt break down tester. We got quite a few testers over the years. It was an ongoing battle of wits to see if they could get a punch out of a desk without doing damage to themselves.
Cleaning up the oil from a 3500 mf capacitor was a chore, but knowing that somebody in the shop had oil on their shoes and pants, and a ringing in their ears from the explosion was just too much to pass up.
Brush type motors are noisy in use or when running as generators. A non polarized capacitor can calm this quite a bit. Spikes my be over 1000 volts as each winding breaks, just like a Kettering ignition coil. Same thing for starter solenoid windings. Done just right, you can get a whopping big spike when the starter button is released. This can erase things, and reprogram things that are not protected. More likely is that a chip just gets hosed and must be replaced.
I suspect that a fan motor turning just a few RPM would not produce much in the way of current flow. You might want to look at the output on a scope as the switch is closed to shunt the motor from high RPM, just to see the load the contactors will be exposed to.
Along these lines, some of these fans are small enough to be used as Ram Air Turbines, just like the big guys. A piece of cowling hinged at the bottom with a spring and a switch to connect the fan to the battery.
The battery will limit the voltage to some extent, and if you need this device, you may just need another 10 feet of altitude or 50 feet of powered flight.
I flew a Champ once that had a DC motor with a 12" wood prop between the gear legs. It was the sole source of power. No battery.
Lynn E. Hanover
Western badge number
8150