I have taken the testing to the next level.
Since it is seldom that I get any real wind
around here I decided to do the next best
thing.
My Ametek motor seems to only want to
gain about 1 volt per MPH of wind so I
decided to gear it up. Since I don't have
a machine shop I went with off the shelf
parts that could be easily modified.
Here is what I used.
- - 4" plumbing test plug.
- - 2" plumbing tast plug.
- ' 1'2" allthread (Threaded rod).
- - 1/4" black iron tees.
- /2" nuts and washers.
I looked all over in a couple hardware stores
to find anything I might be able to use for
a 2 to 1 drive. That is where i came up with the
plumbing plugs. They consist of 2 tapered plates
and a rubber ring, held together with a bolt.
The rubber is shaped kind of like a v-belt.

When the bolt is tightened, the rubber expands.
This allows it to seal on the inner wall of the pipe.
Rubber to rubber shouldn't slip very much.
This allows for some adjustment in the diameter
of the wheel.
Now I needed bearings and a shaft.
I wanted something strong enough to hold the
prop so I decided on 1/2" stock. Since I don't have
a welder, lathe or a drill press this had to be
threaded.
I wasn't worried about zero resistance so I just
wanted something strong and adjustable for now.
I decided to go metal on metal and spotted the
1/4" iron plumbing tees. These just happen to be
about the same inside diameter as the 1/2" rod.
(Did you know that even though the threads are
not the same you can screw 1/2-13 rod into a 1/4"
pipe fitting? About 5 turns and it is really tight.)
I used a 1/2" bit to drill through the tee's so the
shaft could turn inside and screwed an 8" piece
of allthread into the single opening on the Tee's.
I mounted these fore and aft of the motor, offset
just enough so they wouldn't hit the motor shaft.
I mounted the smaller 2" plug in the motor shaft
and the larger 4" on the bearing shaft, allowing
several inches to extend out the front for
mounting the prop. I used double nuts and
washers either side of the Tee bearing to hold
the thrust if the shaft.
2 dimentional adjustment and fine tuning
proved to be a nice thing to have. I can turn
the shaft with my fingers pretty easily under
no load. I haven't oiled the bearing yet and I
still have a few things to finish before she goes
back up so comments are welcome as always.
