Comments on: DC Wind Turbine Motors on eBay – BEWARE

By: Bruce

Bruce — Sun, 30 Oct 2011 15:29:06 +0000

Ed, unfortunately there is no rule regarding geared or not…. you’d need to find the exact make and model and then confirm with the manufacturer. With those wind speeds, you’ll need to make the wind turbine “heavy duty”. Wood blades would be better than PVC, which tend to warp at high speeds – and shatter if they touch the pole.

By: Ed Morton

Ed Morton — Sat, 29 Oct 2011 23:37:24 +0000

Bruce.. I don’t really see anything on variable speed PM motors. If they don’t state that they are geared are they a viable unit? In my case the RPM/VOLTS =< 15 when doing the math on a 1 1/2 HP unit. I live on a mountain ridge southwest of Denver and we get winds most of the time and some gusts of even 70 MPH or better. Strong enough sometimes to move a heavy grill.

By: Bruce

Bruce — Fri, 18 Mar 2011 01:46:39 +0000

Yes, there is only so much energy in the wind – but it varies greatly with the windspeed (cubed). The more blades you have the SLOWER the blades turn, but the more torch (power/push) you have. In the video, he found that with 3 blades he didn’t have enough power/torch to start the blades moving. Once he had 6 blades, the wind blowing on all 6 blades, gave him enough PUSH to turn the motor over. However, at a set wind speed (say 30mph for example) the 6 blades will turn slower (fewer RPM) than a wind turbine with 3 blades…. But again, if your system won’t even start with 3 blades, then you are not producing any power at all.

By: Bruce

Bruce — Fri, 18 Mar 2011 01:38:24 +0000

Permitting – the only thing I can think of would be related to the tower and how high it is… You will never be allowed to connect a homemade wind turbine to the grid, besides, it produces almost no power….

To connect to the grid, you’ll likely need all kinds of expensive equipment – approved inverters, disconnect panels, fusing, extra meters – all of this equipment would cost more money than your DIY wind turbine would ever make in your lifetime.

By: Andy

Andy — Thu, 17 Mar 2011 17:13:22 +0000

if there is a certain amount of energy available from the wind hitting the blades, wouldn’t gearing the turbine up just lose some of that energy through friction. I noticed in that video he used 6 blades, was this to compensate for that loss?

I want to thank you in general for your help. I appreciate it.

By: Andy

Andy — Thu, 17 Mar 2011 16:50:35 +0000

I was considering that and running two windmills if I came across a similar motor. What kind of permitting issues will I run into if running off grid, and is tying into a grid a reasonable option for small systems like this.

By: Bruce

Bruce — Thu, 17 Mar 2011 02:39:31 +0000

Sounds like you will need some gearing to get a reasonable voltage. At the bottom of this page:

http://greenterrafirma.com/DIY_Wind_Turbine.html

is a 5 minute video showing a very simple gearing setup….

By: Andy

Andy — Wed, 16 Mar 2011 19:51:55 +0000

ok thanks.

I now got a treadmill for free and took the motor out of it. it is 90/115 Volts, 1 hp. I can’t read anything else on it but it is perm magnet dc. I tried to look it up and found some info saying it might be 4000/4500 rpm. this is a 44.4 rpm/volt ratio. I have been told to aim for 25, so this seems high. I am doing this as a sort of project, and I would like to see if I could power a couple spotlights for horseshoes or just porch lights or something. I was wondering if this would be possible with a motor like this. I guess my main concern is that I don’t think i could charge a 12 V, and my knowledge of the electronics and battery’s is limited, so I don’t know how options with 12 v batterys differ from my options with 6 v

By: Bruce

Bruce — Tue, 15 Mar 2011 03:38:14 +0000

A dryer motor is no good (induction motor). You need a motor that has permanent magnets.

By: Andy

Andy — Mon, 14 Mar 2011 14:49:25 +0000

I was wondering if a dryer motor would work. They seem to be priced lower, but the hp is generally low as well.

I was thinking 1/3 hp would be low, I was thinking of making a small wind system to charge a 12 V power source.

but I am able to find motors with 1/3 hp, 1650 rpm, 120 – 170 V, 5.3 amps for about 30 USD.

Just wondering what I was missing

By: Sprawl

Sprawl — Sat, 05 Mar 2011 19:29:48 +0000

Yeah, this one is gonna run me about $125 but its worth it in my opinion. i just hope I am successful in being able to build this properly. This is my first venture into a project of this complexity, so it could be interesting.

By: Bruce

Bruce — Sat, 05 Mar 2011 14:56:42 +0000

That sounds like a good PMG. The motor tends to be the most expensive part these days. If you aren’t careful you can spend as much for a motor as a complete commercial wind turbine would cost…

By: Sprawl

Sprawl — Sat, 05 Mar 2011 07:51:36 +0000

Hello Bruce, I am looking to try and do one of these and after reading through the guides and such I think I finally found a motor that will suit my needs. But before I spent the money on it, I figured I would ask your advice first.
Specs:
.75(3/4) HP
24 VDC
200 RPM
33 amp
shaft is 2″ long

Any advice is much appreciated.

By: Bruce

Bruce — Fri, 04 Mar 2011 15:17:25 +0000

You’ll need large blades to turn the permanent magnet motor (generator), but you’ll also get more output… just make sure it’s PMG.

By: Alan

Alan — Thu, 03 Mar 2011 01:06:01 +0000

Bruce,
Would a motor with greater than 1 HP be a problem? I have seen a few of appropriate volt to rpm ratios and all are around 2 to 2.5 hp. Is this OK for a DIY wind turbine application?
Alan