[GreenKeys] Model 15 Electrical and Conceptual Help

[John Nagle]

I've restored two Model 15 machines and three Model 14 machines.

Here's the manual set, on my web site.

    https://aetherltd.com/manuals.html

A few things to do to get started:

- Hand-crank the machine. The fan end of the motor rotates 
counterclockwise. (Turning it the wrong way will not damage
anything.) The mechanism should cycle but the typebars will
not rise, because you're printing the all zeroes character,
NUL. This is a good way to find out if something is jammed.

- Next, gently hold down the plate pulled by the selector magnet and
crank the motor shaft. After a few turns, the mechanism
should idle, as the clutch releases, without not much
moving. If you release the plate, and keep cranking, the
mechanism should start again.

- Repeat that process, but release and press the plate
as you crank the machine. This should cause some random
typebar to print. It will only move about halfway up; the
last half of the travel is done by inertia.

If you get that far, the mechanism is at least partially
functional.

- Get a small 9V battery and use it to temporarily energize
the selector magnet. Resistance of the selector magnet should
be 55 or 220 ohms. 9V is not enough to actually operate
The machine, but it's enough to make it click. If you can
get the selector magnet to move, the receive side is
electrically alive.

The motor is next, but that's for another day.

Here's a motor, on eBay, if you need one.

https://www.ebay.com/itm/287466179623?

I always replace the AC power cord with a modern
3-wire power cord and plug, and connect the
green ground wire to the frame.  I use a big
rubberized cord, so it looks original.
Then I plug the unit into a GFCI and an outlet
strip with a circuit breaker, for safety reasons.
Don't trust the motor insulation without checking
resistance to ground.


			John Nagle