Mini Wind gen question

Max

I wish you had posted the make and model of the turbine.
Is it really designed for 2-6 blades, or is it a 6 bladed machine and you are thinking of removing four ?

Removing the 4 blades will increase the loading on the remaining 2 blades. If not designed for it, a failure at the blade root/hub would be likely.
I am not sure that you would be getting an increase in self destruct speed. You could actually be lowering it.

You will be lowering the output across all wind speeds.

Without any specific info, I would say leave the base design alone and concentrate on adding a furling and/or braking mechanism. Can it tolerate a shorting switch ? Or consider a tilt up tower and lower the turbine when high winds are forecast.

Ken

55 Posts

Aug 13, 2009 09:56 pm

Well dare I say I got it off E-bay. I wont say a homemade unit but its not a mass produced unit. The hub is drilled to accept 6 blades but it is shipped with 3. I also had thought that the load on half the hub would probably split it in half. There is no way to put a brake on it and you have to manual furl the tail. If I added 3 more blades would I be asking for problems on the top end.

Jon C

97 Posts

Aug 13, 2009 10:42 pm

Hi Max S. Automatic furling is not terribly complicated and perhaps you could make your own furling mount. Some of the basics of furling are shown on this link: http://greenterrafirma.com/wind-turbine-furling.html
To prevent overspin and self destruction in high winds, you could use a simple controller that employs back EMF for braking.......the controller simply senses an overvoltage condition and switches the output of the turbine into a resistive dump load. The turbine then works into a high current load that opposes rotation by using the counter electromotive force produced by its own windings. The southwest wind power controllers do this (example...the whisper 200 controller) and provide a "stop" switch that does the same thing manually in the case of a forecast gale force wind condition. Best of luck to you. :-) Jon C.

7 Posts

Aug 27, 2009 07:45 am

Max, would the wind turbine in question come from USA WindGen? I purchased the ~300 watt model and have had good success with it, when the wind blows! We had a pretty good wind storm a month ago and I lost a blade and until I could make another blade, I took off the damaged blade plus a good one, leaving only 4 blades. The claim is that it will run with 2 or 4 but 6 seems to give the best overall performance. I am new to this RE thing also. Good luck.
David

55 Posts

Sep 16, 2009 07:51 pm

Yes I have the 200w version but only 3 blade. I have had it go thru 2 storms that the weathercube said 50mph gust. But I did have the tail turned 20 degrees.Do you know what speed you had blade failure at?I have had no problems yet that were major only a single rust spot.But I had the inside track and got the body and tail powder coated. I have put it into service now after 3 mo of testing. When I finally put it in its permanate spot the wind stops blowing.LOL Its been 3 wks...

7 Posts

Sep 16, 2009 08:26 pm

The root cause was a clearance issue of blade to tower. I think the wind was in the 20's with gusts to 30. I really like the little turbine but wish it did not have the cogging effect of getting it to turn. Don with WindGen is right, when it turns, it charges. I have since put up a PrestoWind PMA with the 48" 3-blade kit. It starts turning at around 3-4 mph but low voltage 4-7 volts but when we do get good wind it cranks it out. I had thought about coupling the little generator to the pma and piggyback off the big blades??? Good luck,
David

55 Posts

Oct 31, 2009 01:18 pm

Last night a blade hit the tower but we had some high gusts.I wonder if I am going to get into a balance problem? lost 1\2 in of blade. Does anyone know what size PCV pipe they make these blades out of?

7 Posts

Oct 31, 2009 08:44 pm

Max, I have already replaced the blades on mine, this is the response I got from Don with usawindgen:

just thin 4" sewer pipe will work fine

You can take the damaged blade and another blade off and run it with 4 blades if need be.

David

55 Posts

Nov 8, 2009 08:48 pm

David
I know I am not in a good wind area but I have a question? Did you ever put an Amp gauge on your USAwind unit. I got the 200W unit. The best wind I get around here I have squeezed 3 amp burst with 1 amp average. Dont get me wrong I am not complaining I just want to compare.

7 Posts

Nov 9, 2009 04:30 am

Max, I have not checked the amps from the wind turbine. I have checked voltage numerous times during various wind speeds and have found up to ~35 vdc. I am on the 3rd generation of blades, I have kept the length of the blades the same but have increased the length and amount of curvature of the blade. This gives more surface area for wind to act upon because I am not worried about rpm because it is like Don said, if it is turning, it is charging. I just wanted to see it start turning quicker with less wind speed. I have found that I cannot keep the blades/hub on the shaft of the gearmotor. I have filed a flat spot on the shaft to allow a better attachment but right not it is not in service. I will be glad to send you a picture of new blade vs. original blade if you like.
David

55 Posts

Nov 22, 2009 05:23 pm

David
Did you have a number I could call or there web address? I live in the midwest and the grain elevators are drying at full capacity so it is noisey. I noticed a strange sound over the noise and it was coming from the wind gen. I lost the web address and I hope if it comes to it they have replacement motors.

7 Posts

Nov 22, 2009 06:42 pm

Max, please let me know about replacement generators, mine started making a terrible noise and I took it down and checked it out and the gearbox is just making a grinding noise.
afusales @ gmail.com
The owner is Don Stutts.

David

55 Posts

Dec 26, 2009 12:48 pm