Helicopter rotor blades to build wind turbine? I have 4 rotor blades from a Bell helicopter.

[Hedges]

The bearings are not designed for vertical support of the blade weight while at right angles to the earth. I think I know what I meant but maybe not.

Not a problem at all, if you start with the right unit.

V-22 Osprey

The V-22 Osprey is a joint service multirole combat aircraft utilizing tiltrotor technology to combine the vertical performance of a helicopter with the speed and range of a fixed-wing aircraft.

www.boeing.com

 

[chrisski]

These blades are big and strong and beautifu! And free! Why won’t they work and work really well?

I have little actually no experience in building wind mill blades, and you do seem smarter than me on this. What I saw in the book I linked earlier, A recipe for a Wind Turbine, there’s a specific way these blades are supposed to be cut, and they look different than the helicopter blades I’ve seen. This is an excerpt from about 20 pages of making blades. If this is similar to a helicopter blade, than perhaps it will work:




Most blades I’ve seen between helicopters, prop airplanes, and paragliders are slightly different and would not switch from one to the other, so I don’t think it’d work well with a windmill.

There’s a bit of talk about repurposoing other parts for windmills that does not work out well, mostly about using an alternator and how it is much better to make your own.

If you really want to try this, if you go to the forum Fieldlines.com, I think you‘ll get good answers. A project with building a windmill out of helo blades is going to be pricey even if the blades are free.

 

[WYtreasure]

I’m thinking 80 to 100 rpm. Doesn’t need to turn any faster. On the hello they spin up to 350 - 400 while twisting during every revolution of the rotor head. By adjusting the pitch I can get max power and a very large swept area

So you do have the transmission, rotor head and all the smokey mirrors to go with it?

100 rpm they will last forever, or until a branch or ultralight smacks into a blade.
An odd number of blades is for balance, I think.

 

[Blue Sky Stu]

Yes. Pretty much. I’ll have to make a few parts for the rotor head. I have the transmission and lots more parts. A friend will help me with computer controlling the blade pitch with a stepper motor for efficiency and max speed. it’ll be easy to connect a generator to the output shaft of the transmission.

 

[Blue Sky Stu]

I plan on an 80 ft tower. No branches. And my ultralight friends know where my runway is ?

 

[WYtreasure]

I plan on an 80 ft tower. No branches. And my ultralight friends know where my runway is ?

Holy Crap, you're going to need a strobe light too. ?

 

[Don B. Cilly]

But... once you've built the tower - and stabilised it, the rotor hub, the pulley system for the alternator, the all and the sundries, the fact that you got the blades for free isn't going to make that much difference, is it?
Making your own light-weight, wind-optimised ones would probably make more sense anyway.
-

 

[Ozark Tinkering]

Seriously though, how about a Vertical Axis contraption? A 6 to 10 foot diameter plate, top & bottom. A couple supports midway to keep them from bowing too much.

He'd have to figure out a way to balance his combine laid on its side on an 80' tower for that configuration. Using a horizontal shaft he only needs to find a high bluff to park the combine next to and hang over the edge...

So iffin @Blue Sky Stu is really serious even slowing it down to 80 rpm he better get trained up in dynamic balancing. IRD has some top notch equipment for that and training on vibration analysis. I installed their equipment on a 6 cell cooling tower for a 50 megawatt geothermal plant in SoCal back in 1990 because we kept losing blades and very expensive right angle gear drives. 3 of us got certified by IRD in the use. The fans were each powered by 200hp. 480volt motors and when you lose a blade from one of those you don't want to be anywhere outside. After you get done collecting all your vibration data you'll use a formula to determine the weight to be added to the blade tip. Then you'll have to extrapolate from that how much weight to add at the hub instead since you don't want it way out on the tip.

Start here they offer training too...

Vibration Monitoring Systems by IRD Mechanalysis Limited

On-Line Vibration Monitoring Systems by IRD Mechanalysis for round the clock Vibration Monitoring of critical and semi-critical rotating assets

www.irdmech.com

 

[Blue Sky Stu]

I’m planning on an accelerometer as part of my control and monitoring. I hadn’t thought about it but that should help with balancing. Any out of balance due to icing or damage would cause a shut down. These blades are balanced at much higher speeds on the helicopter. These final drive transmissions are fairly small. Maybe 2 ft square and a foot thick. 250 pounds. It’ll go on a tower. These blades are about 45k for a new set of 2. They are pretty incredible structures. How could I possibly create better ones? I’m surprised there’s not more interest in them.

 

[RV10flyer]

They most likely have a symmetrical airfoil. I would shorten the blades, add 4 more directly behind for a stiffer 8-blade system. Then using wood or foam, reshape all airfoils to a proper wind turbine design and balance. Then ensure your gearboxes are properly lubricated, change oil pickup locations as needed, add covers and seals where needed. Do you have the dc generators or 3 ph brushless ac alternators? What about a/c to dc converters. We had 2 ea 45,000W and 1 ea 30,000W a/c brushless generators outputting 115/200VAC at 400hz. We utilized both a/c and dc. We had 2 ea 200A converters outputting 28VDC. That stuff would be REAL nice to have attached to your gearboxes already. Of course some modifications could be made to get the proper 60 hz frequency.

 

[Ozark Tinkering]

I’m planning on an accelerometer as part of my control and monitoring. I hadn’t thought about it but that should help with balancing. Any out of balance due to icing or damage would cause a shut down. These blades are balanced at much higher speeds on the helicopter. These final drive transmissions are fairly small. Maybe 2 ft square and a foot thick. 250 pounds. It’ll go on a tower. These blades are about 45k for a new set of 2. They are pretty incredible structures. How could I possibly create better ones? I’m surprised there’s not more interest in them.

So how much h.p. do you figure to produce with this well balanced post apocalyptic behemoth?
Have you calculated the necessary wind speed just to get it spinning without excitation of the armature?
What size output shaft will the compact gearbox have?

Have you thought about maybe putting it on display at Burning Man?

 

[RV10flyer]

It can be done. It will just take a lot of money, time and energy. I hope you have a lot of 30+ mph winds. There is a lot of friction in those drivetrains, even with the tail rotor driveshaft not attached. Have you tried spinning the rotor on an assembled helicopter?

 

[RV10flyer]

Is this from a Bell 206?? Metal blades or composite??

 

[RV10flyer]

I used to overhaul UH-60 Blackhawks (Our composite blades were 250 lbs each with a 52’ rotor diam) then small turbine engines 350-1800 shp/5,500 lbs thrust for helis and bizjets.

 

[Hedges]

Any out of balance due to icing or damage would cause a shut down.

"Shut down"
What sort of brake do you plan to use?

 

[Ozark Tinkering]

It can be done. It will just take a lot of money, time and energy. I hope you have a lot of 30+ mph winds.

...that don't change direction abruptly. I'm guessing iffin he's close to the Oklahoma panhandle he's got plenty of wind.

 

[Blue Sky Stu]

Is this from a Bell 206?? Metal blades or composite??

Yes! Metal blades

 

[Blue Sky Stu]

I haven’t got a generator or alternator design yet. Love to hear everyones thoughts. The gearbox doesn’t have lots of friction. Pretty simple. Output shaft is like 2” splined. I can always machine it to anything I need. No idea yet for a brake. But I plan to furl the blades when the Oklahoma Squall lines show up. I have thought about using a Ford automatic transmission between the gearbox and generator to change gear ratio from light wind to heavy wind. Using rpm sensor and wind speed to set diff shift points. Would eat some energy though. I also have a combine hydrostatic pump and motor system that would be infinitely variable. Fun brainstorming

 

[Blue Sky Stu]

I used to overhaul UH-60 Blackhawks (Our composite blades were 250 lbs each with a 52’ rotor diam) then small turbine engines 350-1800 shp/5,500 lbs thrust for helis and bizjets.

Hey RV10flyer, I fly an RV8. Where ya located?

 

[Blue Sky Stu]

Quite the bird catcher it would be.

Seriously though, how about a Vertical Axis contraption? A 6 to 10 foot diameter plate, top & bottom. A couple supports midway to keep them from bowing too much.

They just don’t appeal to me. I have a 100 year old windmill that just spins in the wind and is pretty. Hoping for a nice slow turning turbine that will make some energy. Doesn’t have to be super efficient

 

[Hedges]

The gearbox doesn’t have lots of friction. Pretty simple. Output shaft is like 2” splined. I can always machine it to anything I need. No idea yet for a brake. But I plan to furl the blades when the Oklahoma Squall lines show up. I have thought about using a Ford automatic transmission between the gearbox and generator to change gear ratio from light wind to heavy wind.

Static friction to overcome from a standstill?
Helical gear reduction being run in reverse?

A magnetic load and bearings, no gears, could have less start-up drag. Except for "cogging" with permanent magnets, so powered rotor coil might have less drag (brushes would be drag, and magnetic remanence would be drag if not degaussed)

Big turbines are rotated into the wind by motors, and spun up by motors rather than by wind.

 

[WYtreasure]

They just don’t appeal to me. I have a 100 year old windmill that just spins in the wind and is pretty. Hoping for a nice slow turning turbine that will make some energy. Doesn’t have to be super efficient

That's Okay, your blades have some momentum now. Off ya go!

To what degree can the blades be feathered & reversed?
I don't think I would chop or reshape the blades. If the design turns out to be Good-N-Simple perhaps a bunch of old blades will find a new life.

 

[Blue Sky Stu]

I’ll have to work on that as I build my rotor head. I’m hoping for full feather. What would be my lightest angle?

 

[shadowsteve]

Was hoping for some help and positive feedback. But ok. Let’s go with that’s stupid. ??

A noble idea but honestly not a practical one. Just because you got a free box of nails doesn't mean it's a good idea to build a house

 

[WYtreasure]

I’ll have to work on that as I build my rotor head. I’m hoping for full feather. What would be my lightest angle?

If you're asking me about angles, depending upon difficulty of build I would say -10 to 100 degrees. You could practice autorotation, reverse the gears to dislodge ultralights and geese or just play around while enjoying a cold one with your buddies. ?

If we're discussing your plane. Damn nice taildragger ya got there.