I'm building a HAWT

[rcavictim]

More pics of AZ drive and slip ring assembly.

[rcavictim]

Here are some pics of the DIY blades.  Blade attack angle will be subject to 'tune for best performance once installed', and is adjustable and can be locked.  Turbine diameter 13 feet.

Stainless nose cone is a wok cover from the dump, has been sandblasted and painted white.  I am the Master of Repurpose!  

The blades are cut out of a 1/2" wall heavy 8" ID water main PVC pipe.  PVC is heavy, brittle, and not very strong.  The centrifugal forces on a 12 pound blade at 250 RPM exert over 500 lbs at the hub.  I have NEVER seen anyone make PVC blades anywhere near this large.  To try to get them to survive I have imbedded a 3/4" wide X 1/8" thick,, mild steel strip down the length of each blade buried in a machined slot.  There are a dozen 1/4-20 countersunk bolts tapped, screwed through the blade from the back (convex) side and welded to the strap, each bolt at about 6" spacing.  Two grade 8 bolts secure this strap to the metal bracket at the hub.  The force of the oncoming wind will put the strap in tension and the PVC blade in compression.  

The surfaces, despite the embedded steel spine and bolts, is smooth.  Much work went into these to save the $500 cost of ordering a set of Chinese made fiberglass blades out of a dealer in Texas.  I hope to be able to order a set of those anyhow as they would likely save the day down the road as needed spares.  Still, I am plowing ahead into uncharted territory making PVC blades this big and being all DIY'able this is valuable R&D that others can potentially benefit from.

PVC is difficult to get paint to stick.  I sanded it, cleaned well with acetone and also lacquer thinner (couldn't find a can of lacquer thicker) Ha ha    , and painted the blades with some white automotive lacquer.  That gave a surface that my red enamel for the racing stripes could adhere to.  This will look pretty when it first goes up but I have a hunch that the leading edge of the blades from the impact of wind, rain and molecular collisions will make the blades show their true blue colors in time.

Cheers!

Rob

[mike90045]

Are you going to power a city with this ?

[rcavictim]

Are you going to power a city with this ?

Go ahead, mock me.    As far as I'm concerned, the cities, bless them, are on their own.  I'm on a private power trip out here.

[AdeV]

I continue to be alternately gobsmacked and speechless by this project...

There is some exquisite work going into this HAWT, the scope and sheer size of the thing would challenge a well-equipped team, let alone a "man in his shed".

BTW, I don't think Mike was mocking you, I think he was just impressed at the scale I am too... Just how many watts to you anticipate making from this thing? (assuming a sensibly windy day)

[rcavictim]

I continue to be alternately gobsmacked and speechless by this project...

There is some exquisite work going into this HAWT, the scope and sheer size of the thing would challenge a well-equipped team, let alone a "man in his shed".

BTW, I don't think Mike was mocking you, I think he was just impressed at the scale I am too... Just how many watts to you anticipate making from this thing? (assuming a sensibly windy day)

Ade,

I didn't think Mike was mocking me, hence my winky.  This machine is the hardest ~2500 watts I'll ever work for.  With a proper slow speed gen head in the nacelle, not repurposed wheelchair motors strung together, and a real 14-15 foot commercially sourced fiberglass prop I could add a kW within the strength of the tower I suspect.  Not having guy wires is a weak link.  I don't like the way guy wires makes a large part of your field useless.  Working mostly alone pretty much dictates a tilt down system as I have designed.  I'm really pleased and proud of how it looks.

The BGT definitely represents the hardest 10-15 kW I'll ever work for.  The good news is on that one, according to a professor of mechanical engineering at McMaster University who looked at my design, it should make 10 kW in a "not so big wind".  I need to get back on that project seriously this summer.  I am so close to completion now.

Thank you friends for your keen interest and moral support.  I truly appreciate it.  I've really been dragging lately and having trouble getting this done.  Hope I gain some momentum in the spring, winter is such a terrible, depressing time for me.

Cheers,
Rob

[mike90045]

I saw and understood the wink.    OMG ! you didn't abandon the giant VAWT, and re-purpose it's guts, you are building and 2nd  turbine !!!  You got 2 cities you plan to power, or do you just like redundancy with a second mode of backup?

[rcavictim]

I saw and understood the wink.    OMG ! you didn't abandon the giant VAWT, and re-purpose it's guts, you are building and 2nd  turbine !!!  You got 2 cities you plan to power, or do you just like redundancy with a second mode of backup?

Hi Mike,

Where I live, if my BGT VAWT fails in January it will be five months before I could get to do any repairs.  I hardly ever even blow snow off my driveway because that represents hard outdoor winter work which my body has told me specifically to not ask for.  That would be four months or more without a source of power except diesel.  Not an option.  I decided a smaller backup wind turbine was absolutely essential to my off-grid plans, so....

The BGT was taking so bloody long I figured a smaller, simple, HAWT could be whipped up in short order.  Well, nothing I do can ever just be whipped up in short order.  This smaller backup turbine has been a 2+ year time sink at this point, but it is almost done.

Just before this past Christmas I scored a super deal on 5.5 kW of solar photovoltaic panels, 21 pieces of 265 watt panels new for 46 cents a watt.  I didn't hesitate too long to pull out my credit card.  I hope to drop everything else I'm doing as soon as the weather is warm enough and install these.  Wow, what a wonderful complement to my off-grid power plans here!    All I need to make this subsystem a go is a MPPT charge controller for my 48 volt battery bank/inverter now installed and ready.  

Cheers,
'I'm on a power trip' Rob

[rcavictim]

Here is a video showing the active azimuth drive system under test.

[rcavictim]

Time for an update on progress with my DIY HAWT project.  Last fall I managed to get the DIY,  20m self standing, power tilt up tower installed in my field. Took me two years to build that tower.  Just sits on the ground, no foundation, no guy wires, NO PERMISSION, NO INSPECTORS, NO PERMITS.     During the winter months I was able to fabricate the power azimuth drive platform with slip ring assembly, the nacelle containing the four repurposed, neodemium magnet, brushless , 3-phase, 24 volt, 650 watt AC wheelchair hub motors which are mechanically ganged on the propeller shaft with no gearbox. The 3-phase output of each individually is turned to DC with a beefy bridge rectifier, boosted with an electrolytic capacitor and then all four DC sources are wired in series to obtain max voltage possible output. This runs about 500 feet one way to the house through #2 AWG aluminum and #4 AWG copper cable. Loss will be negligible at 60 volts and 40 amps.

I managed to fabricate the sensing tail fin system that uses wind direction against the fin to activate one or other of two microswitches which relays drive commands through a buffer and time delay circuit to the AZ/YAW DC gearhead motor.  This sysetm keeps the turbine tracking straight into the prevailing wind direction.  

To take advantage of a power AZ capability as a substitute for power controlled blade pitch, I have also set a large format 3-cup weather station tachometer on an extension arm located below the main turbine propeller.  The 3-cup spins a beefy 72 volt PM, with brushes tape drive motor.  This has been feeding a 12 volt neon automotive light in my house basement all winter, reaching full brilliance on many occasions when the winds are elevated.  The power from this tachometer generator is used to power a small 28 volt PM brushed armature gearbox motor from a peristolic pump salvaged from a refreshment vending machine.  This gearmotor is able to wind up a spring coiled around a shaft which is allowed to rotate up to 90 degrees.  The microswitch plate is mounted on this shaft.  When low winds are present the microswitch 'zero point' ( i.e. both switches open circuit) to the wind vane is in line with the nacelle pointing at the wind direction.  As the 3-cup starts to spin, it generates rotation against the spring on the microswitch plate creating a new 'zero point' which the AZ motor is commanded to maintain in reference to where the wind is holding the direction vane.  By this technique there is an increasing offset nacelle pointing angle to the oncoming wind introduced by this control system.  When the winds are dangerously high, this system will keep the turbine propeller at 90 degrees to the prevalent wind direction, and if that dangerous wind changes direction the 90 degree to it null pointing will be actively maintained.  A further function of the 3-cup wind sensor it to activate a shorting relay which shorts the generator output whenever the blade is commanded to the 90 degree out of wind offset.

Is anyone following this?  

So this just past Saturday I had a couple of friends over and between the three of us we managed to get the top package out to the field from the shop and installed onto the top of the tilted down tower.  All the cabling, already in the tower from last year was terminated to the top package, propeller was bolted on, the wrong way at first, but unlike NASA and the Hubble I caught the mistake before we flew it.    The top package with blade weighs about 350 lbs.  I had to add a total of 500 lbs in 100 lb. concrete patio stones as counter balance at the bottom to make the system work properly.  I could probably add yet one more patio stone to the mounts I fabricated at the bottom of the tilt tower to receive as many as 8 of these.  The 12 volt electric winch is handling the job like a champion right now, so no worries.

I have uploaded two videos to Youtube.  One showing me and friend installing the propeller incorrectly after which I had to go fetch the nosecone which was needed to determine the lock down position on the shaft for the prop.  During that walk back to the shop it occurred to me that we had just placed the blade wrong side out.    A friend who installs wind and solar for a living tells me people make this mistake all the time.  As he puts it, it is during the champagne moment that one has to tell folks it is a downwind turbine!  

https://www.youtube.com/watch?v=hUEX6yYqG6k

https://www.youtube.com/watch?v=inm-YjwtF6I

I took still pictures of the work yesterday.  I'll post them when I get a chance to shrink them first.

I still have to fabricate the electronics control package that will live in the weather tight electrical cabinet now in place at the base of the tower.  That won't take long.  Where I have just arrived is almost the Champagne Moment, so this weekend represents a huge milestone marker for this project.  

The damn thing is finally UP!  

Regards,
DIY Rob


edited to correct typo.  I don't have a 'hose basement'! 

[SteveU.]

Following with interest, yes.
Yours is a self monitoring. self-correcting "upwind?" turbine.

A local fellow here built an actual downwind turbine. Got real cranky after suckered on dumping a few hundred grand into his project for the feed-the-grid for $'s Myth.
They did not want his power. He could not force this no matter how long he tried, and how many of thier compliance $'s hurdles he would jump over.
I've alway'd been curious how this thing turned itself for protection with changed wind directions and forces. I've actually seen it head direction rotating recently. Haven't seen it ever spinning/producing though for years. Locked rotor. It never looked like it had blade feathering? capabilty at the small center hub.
Ah . . . he does not respond to questioning. Greets would be visitors with a shotgun now. Bitter, bitter man now. He'd be a happy man now if he'd just been building smaller with far less bucks out for just personal self-sufficiency power.
What I have discovered in the woodgassing fueling area also - - WHY; and for WHO a fellow is developing/building if far more important than the actual system for sucess satisfaction.

Thanks Mr Rob. Now I know how it's doing this rotating turning.

Regards
Steve Unruh

[rcavictim]

Here are a few construction picture you guys haven't seen yet of the nacelle.

[rcavictim]

Here is the microswitch assembly that is modulated by a finger on the direction sensing tail fin.  This plate is rotated up to 90 degrees as described in previous text by the wind strength related power from the 3-cup anemometer on the same tower.

The rest of the photos show how I can still get it up these days. 

[rcavictim]

And here it is UP!

The nosecone on the prop is a cooking Wok stainless steel cover sandblasted and painted white.  Found it at the local landfill site.  I am truly the master of recycle and repurpose.

The propeller shaft is 66 feet above grade in nice clear, low turbulence air.  I have an excellent siting for this turbine.

[rcavictim]

You can view a test I did spinning the pack of generator heads in the shop.  Since the test I did pack high modulus of elasticity silicone sealant into all the clearance fit motor mounts and let cure for two weeks undisturbed.  It now runs silently and there should not be little piles of metal particles accumulating under these moving motor mount bolts.

https://www.youtube.com/watch?v=n9t2xm57t34&feature=endscreen