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Step 5Physical Limits of the Portable Wind Generator:
I've test run this generator in winds up to 35mph (15.65 m/s), a "moderate gale", but don't recommend it. After all, the simple device is made of wood, and held together with glue and wood screws.
After about 5 hours of use in high winds, in an isolated area, I noticed a slight drop in voltage, and cautiously took down the dangerously spinning device, to inspect it, and noticed that the allen set screw, as well as washers and nut on the generator shaft arbor, had begun to work themselves loose! To correct the problem, I added aluminum shims to the generator shaft, neoprene washers, and a lock nut (detailed above). The spring hinge, fitted with special oversized wood screws, remained tight and required no adjustment.
This wind generator was designed for, and is best suited, for "light breezes" (5 mph = 2.24 m/s) to "strong breezes" (25 mph = 11.18 m/s), although a 21 Amp, 12 Volt battery was quickly charged in the 35mph windstorm test. And it was satisfying to observe the blades and generator desperately furling back-and-forth, while the entire unit, and the fiberglass mast, strained against the guy-lines, but held, in the insanely violent 35 mph (15.65 m/s) winds.
Also, violent, gusting winds will put a strain on the telescoping lock-nut of the 10 foot mast, causing the upper section to slowly work its way down an inch or two, giving the illusion that the guy-lines are becoming slack. The same applies to the lock-nut to the guy-line mount, on the mast.
Being portable, this wind generator will, more than likely, be used in close proximity to people, so safety is paramount. Keep the device under a watchful eye: If the winds really pick up, take it down. And never leave any portable wind generator unattended. Use the same care and precautions as one would use with a portable gas generator.
The 3-blade (and 2-blade) arrangement self-starts @ 11 mph (4.92 m/s) constant wind, and @ 13 mph (5.81 m/s) gusting wind, with the flywheel action of the thin, but dense, 3-blade arrangement sustains spinning of the blades down to 5 mph (2.24 m/s) wind speeds.
I have found that, on days of 5-10mph winds (2.24 - 4.47 m/s), "light breeze" to "gentle breeze", an extendable hiking staff, with a rubber foot, is quite useful to push-start the blades, intitate the battery charging process. Two or three of these "jump-starts" is all that is usually needed, over the period of a "light-to-gentle breeze" day, to keep those blades spinning and charge a 21-42 Amp battery pack.
Another way to "jump-start" the blades, if mounted on an unusually tall mast, is to simply run the battery pack power through the "generator" for a second or two, to get things moving. A 24 inch long string has been attached to the lower-rear of the tail fin, to serve as a simple telltale: 90 degrees = no wind; 45 degrees = sustainable blade speeds; 30 degrees to 0 degrees (parallel to the ground) = battery charging speeds.
As mentioned earlier, the generator is not yet weatherproof, even though all wood surfaces have already been given a good marine varnish. Future plans call for a simple, aerodynamic cowling, over the generator only, made from aluminum sheet metal and aluminum pop rivets.
Stay posted for more information and updates.
After about 5 hours of use in high winds, in an isolated area, I noticed a slight drop in voltage, and cautiously took down the dangerously spinning device, to inspect it, and noticed that the allen set screw, as well as washers and nut on the generator shaft arbor, had begun to work themselves loose! To correct the problem, I added aluminum shims to the generator shaft, neoprene washers, and a lock nut (detailed above). The spring hinge, fitted with special oversized wood screws, remained tight and required no adjustment.
This wind generator was designed for, and is best suited, for "light breezes" (5 mph = 2.24 m/s) to "strong breezes" (25 mph = 11.18 m/s), although a 21 Amp, 12 Volt battery was quickly charged in the 35mph windstorm test. And it was satisfying to observe the blades and generator desperately furling back-and-forth, while the entire unit, and the fiberglass mast, strained against the guy-lines, but held, in the insanely violent 35 mph (15.65 m/s) winds.
Also, violent, gusting winds will put a strain on the telescoping lock-nut of the 10 foot mast, causing the upper section to slowly work its way down an inch or two, giving the illusion that the guy-lines are becoming slack. The same applies to the lock-nut to the guy-line mount, on the mast.
Being portable, this wind generator will, more than likely, be used in close proximity to people, so safety is paramount. Keep the device under a watchful eye: If the winds really pick up, take it down. And never leave any portable wind generator unattended. Use the same care and precautions as one would use with a portable gas generator.
The 3-blade (and 2-blade) arrangement self-starts @ 11 mph (4.92 m/s) constant wind, and @ 13 mph (5.81 m/s) gusting wind, with the flywheel action of the thin, but dense, 3-blade arrangement sustains spinning of the blades down to 5 mph (2.24 m/s) wind speeds.
I have found that, on days of 5-10mph winds (2.24 - 4.47 m/s), "light breeze" to "gentle breeze", an extendable hiking staff, with a rubber foot, is quite useful to push-start the blades, intitate the battery charging process. Two or three of these "jump-starts" is all that is usually needed, over the period of a "light-to-gentle breeze" day, to keep those blades spinning and charge a 21-42 Amp battery pack.
Another way to "jump-start" the blades, if mounted on an unusually tall mast, is to simply run the battery pack power through the "generator" for a second or two, to get things moving. A 24 inch long string has been attached to the lower-rear of the tail fin, to serve as a simple telltale: 90 degrees = no wind; 45 degrees = sustainable blade speeds; 30 degrees to 0 degrees (parallel to the ground) = battery charging speeds.
As mentioned earlier, the generator is not yet weatherproof, even though all wood surfaces have already been given a good marine varnish. Future plans call for a simple, aerodynamic cowling, over the generator only, made from aluminum sheet metal and aluminum pop rivets.
Stay posted for more information and updates.
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