Next drill two
3.5mm holes through the wheel, on each side of the centre
hole. Press the wheel back onto the stepper motor.
Cut the length
of 90mm diameter PVC pipe length ways in two places at
90 degrees apart, to provide a length of quarter pipe
Drill a couple
of 3.5mm holes in the middle on the quarter 90mm pipe
as shown. These holes need to match the holes drilled
in the aluminium wheel.
Next cut the
pipe as shown. This gives us our propeller profile. Clean
up all edges with a file and sand paper to remove any
Cut and drill the piece of 25mm PVC
pipe as shown. The slot at the back needs to be wide
enough to fit the tail into.
Using the stainless steel hose clamp,
clamp the stepper motor to the 25mm PVC pipe as shown.
Make sure it is tight. Once in place it should not move.
Next you need to put together your
circuit board, details are on the next page.
Cut the 3mm
ply wood to a tail shape ( any shape will do, get creative!
) and screw to the 25mm PVC pipe as shown. Position the
rectifier circuit board and battery holder on the tail,
mark hole location and then drill the tail to suit.
Once you have
assembled the rectifier board, screw it and the battery
holder in place and wire to the stepper motor.
the propeller onto the stepper motor. A couple of drops
of engine oil on the bearings will help protect them from
And that's it.
You can now mount the windmill on a post with a 8mm bolt
screwed into the top as a mast.