Windmill

Home built wind mill

Here it is in all it's glory... not even blown up yet.... 22" plastic blades on a home made steel hub.

It spins a 3 phase permanent magnet servo motor.

It sits on top of a 30' tower, and is (was) subjected to gusty winds up to 70+ MPH.

Measured peak output was about 700 watts. Power output over a year averaged about 1.8 KWH per day. Just small potatoes, but a fun experiment anyway.

One particularly gusty night it exploded. Repairs are in progress. Need new blades...

Close up showing tail.

One morning after a particularly nasty gusty storm, it looked like this.

I found the tail and some of the blade bits. It looks like one blade broke off at the edge of the metal blade "sandwich". There were no impact marks on the first blade.

Once the first blade was off, the vibration broke the tail off which apparently impacted another blade along the middle of its length. Thre were nasrty impact marks on the tail, and the second blade was shattered into bits in the middle.

The alternator on this mill was pretty small and I think it didn't provide a sufficiemt load and let the blades "run away" under super high winds. When I rebuilt it, I'll use a bigger servo.

I scavange the salveage yards regularly and always keep an eye out for permanent magnet motors and generators.

Here's a few of the 3 phase PM servo motors I've aquired for such experiments. The largest one at the left rear is rated at 14.7KW.

(note: I did repair the mill with new blades and a larger "generator" and ran it for another 3 months, but then we moved and our new house doesn't have much wind so this hardware is in storage for a while.)