The 260V 5000rpm motor that 'mill is designed for has a cut-in speed of 375rpm, near as I can calculate your motor has a cut-in of 480rpm. Your rotor is bigger (aka slower) than the original 48" one. So, your mill will have to have a wind about 1.5x what the original would work in. I calculated out a faster blade for my Chispito:
Optimized 4 foot windmill rotor made from 4" Schedule 40 PVC pipe. For CCW rotation, root of blade 3/4" from the center of hub, TSR of 8 @ 5 degrees AOA, loaded RPM 375@6.7MPH(3M/S) 1232@22MPH(10M/S):
Cut a 23-1/4" length of 4" Schedule 40 PVC pipe lengthwise into 4 equal pieces.
Take one and lay the inside of the pipe down and oriented left (root) to right (tip).
On top-left hand corner drill a 1/4" hole 3/4" from the left (root) and top (trailing edge).
Drill another 1/4" hole 3/4" to the right of that hole.
Mark the right edge (tip) at 1-5/16" from the top (trailing edge).
- " from the right (tip) mark it 1-7/16" from the top (trailing edge).
- " from the right (tip) mark it 1-5/8" from the top (trailing edge).
- " from the right (tip) mark it 1-13/16" from the top (trailing edge).
- " from the right (tip) mark it 2-1/16" from the top (trailing edge).
- " from the right (tip) mark it 2-7/16" from the top (trailing edge).
- " from the right (tip) mark it 3-1/8" from the top (trailing edge).
This should be 5-1/4" from the left (root).
"Connect the dots" with a smooth curve. Use a french curve if you have one.
Cut the bottom part off and discard.
Sharpen the top (trailing) edge on the inside only! Do not sharpen the 3" on the left (root).
Round off the bottom (leading) curved edge and the tip.
