Author Topic: Would like to share ideas for VAWT (Read 5527 times)

nvmike · « **on:** March 04, 2005, 01:55:56 AM »

I have very limited wind here, have started a VAWT and a PM Gen. The VAWT is up and turning and the dual rotor RM gen. is putting out some by hand turning on the work bench (no spec. yet). My idea is low speed, high torque, belted up 100:1 and connected to the PM gen. I do not expect great efficiency, but like to experiment. Would be interested in sharing ideas with others that are interested in VAWT.

I now have the VAWT atop an 8 by 12 ft shed with the shaft extending into the shed where I hope to belt it to the gen. soon.

I have learned one thing so far, secure the ladder before letting the mill turn. Left me stranded on the roof yesterday.

dudevato · « **Reply #1 on:** March 03, 2005, 07:10:55 PM »

Have you any pics of your setup? Wouldn't gears and chain loose less power to 'drag' than belts and pulleys? I've made 3 or 4 'hobby' windmills from 10 speed bicycle wheels with 3 and 4 sheepmetal blades attached for a dia. of some 5 feet. I get quite a bit of wind here (desert of southern california) and the darn things blow apart. I'd love to make something that would spin for a few years without worry. I was thinking of a VAWT, maybe from a few smaller oil drums. It will be on top of my shop (flat roofed sheetmetal building) I was thinking it would be cool if it could turn a grinding wheel or saw blade or Something.

Norm · « **Reply #2 on:** March 03, 2005, 07:13:28 PM »

100:1 ....that's an awful high ratio!

especially for belt drive try chain drive instead.....

( :>) Norm.

nvmike · « **Reply #3 on:** March 03, 2005, 07:23:54 PM »

No pics yet. Will try to get a few this weekend. Yes, chain and sprocket would be better than belts, but have the pulleys and belts and if this works will go to gears and chain later. I plan to do the 100:1 via two 10:1 pulley arrangments. I know I will have mechanical loss but want to get something turning and will work on improvements as I go. Thanks for reply.

ghurd · « **Reply #4 on:** March 03, 2005, 07:26:06 PM »

I agree.

Bike chains are 'more gooder'.

And 100:1 is a lot.

Someone else could chime in now. If it works in low wind, will it melt in high wind? Will the low TSR keep it in check? 100:1 and all.

G-

nvmike · « **Reply #5 on:** March 03, 2005, 07:32:19 PM »

I have not figured out how to keep it in check in a high wind. Maybe a disk brake at the bottom of the verical shaft, with some way to engage at high wind speed, still thinking on this.

Warrior · « **Reply #6 on:** March 03, 2005, 08:46:45 PM »

I think the 100:1 gear ratio is way too high unless you want to build a HUGE machine.

Your genny will spin 100 times faster than the mill, but the mill will have to supply 100 times more torque.

I did a little experiment once...took an engine flywheel, mounted it to an axel. Then I took a starter gear and put it on the shaft of a 3/4 HP 110v ac capacitor excited induction motor. Mounted everything up for a 15:1 ratio. Put a handle on the flywheel.

Simple math said I would need about 50 lbs of force to get the motor charging at 1800 rpm.

Results... Getting the motor up to speed was quite easy, but when I flashed the field and it started generating (no load), man was that thing HARD to turn. We only mananged to get 50 volts from it max. Once it self excited it would keep generating even though it was operating well below the + 10% slip speed needed.

It was fun, and we got some laughs cranking that thing as seeing who could get more volts out of it.

Good Luck,

Diego

healerenergy · « **Reply #7 on:** March 03, 2005, 08:53:31 PM »

You need a centrifical force govenor that tilts the blades to regulate the speed. I have designed one for the three blader I am working on.

RP · « **Reply #8 on:** March 03, 2005, 09:03:40 PM »

I agree, 100/1 is way too high unless the rotor is huge. How about some dimensions on what you want to build? If we had a better idea of the rotor size maybe we could help more.

I built a small TDR Savonius a couple years ago (20"X20"). Still flying.

rp

electrondady1 · « **Reply #9 on:** March 03, 2005, 09:09:51 PM »

1 am very much interested in vawt. ive had a small proto type up for one year it is direct drive and can make 14 volts but very few amps as i built it before i got on line and discovered this site. i am using the same design criteria for my present project but a little larger pmg. i will bench test within the next week and hope to have it up in the wind shortly after. the next step for me will be a gear drive. i will be using the fly wheel from an automatic trans mission to get the speed up . it's 18 to one using a starter gear on the shaft of the pmg. the bug has bit me really hard. keep posting

electrondady1 · « **Reply #10 on:** March 03, 2005, 09:31:50 PM »

just caught you responce , i think you should build the impellers strong enough to take any wind but if you think you need to put a brake on it . you could use the rear axil from a automobile and leave the emergancy brake in place.

Shadow · « **Reply #11 on:** March 03, 2005, 09:41:50 PM »

Here's what you need, be easy to hook up brakes.

nvmike · « **Reply #12 on:** March 03, 2005, 10:29:46 PM »

Wow, thanks for all the great input, gives me a lot to think about.

My first design was 24 ft. diameter with four "jib" type sails, scaled it down to 12 ft diameter now, and was getting less than 5 rpm with 5 mph winds, therefore was thinking of 100:1 to get about 500 rpm, but with you input will have to rethink this.

I appreciate all the input, thanks. Hope to share the results with you all.

fishfarm · « **Reply #13 on:** March 04, 2005, 06:10:20 AM »

Have you seen this design?

http://www.energytransfercorporation.com/photosandmovies.html

electrondady1 · « **Reply #14 on:** March 04, 2005, 06:44:42 AM »

what a piece of crapp. that has got to be government money at work . could they get any more moving parts in there. it's ugly.

Norm · « **Reply #15 on:** March 04, 2005, 07:44:53 AM »

This is also an answer for the cogging issue

on an F&P...with the F&P connected to one axle

and a smaller genny connected to the other ...

the small genny with a light wind...too light to

operate the F&P...when a stronger wind comes up,

a solenoid (from a GM starter?)that is energized

and operates the brake (that is already there)

when the wind again dies down to a predetermined

speed the solenoid kicks the brake off....

If a newbie(no offense intended) doesn't understand

this part about

the solenoid being able to toggle the brake on

and off ...grab one of those retractable ball-point pens

with the button on top...click (down)

click (up)

Hope this helps someone

Have Fun!

( :>) Norm.

Norm · « **Reply #16 on:** March 04, 2005, 11:38:56 AM »

Would be neat to have a drill press ...chuck

right on the end of the VAWT ...bring the table

up to the work....drill 1/2 inch holes ...make a

nice rig for drilling wells wonder what kind of

holes you could drill in a 20mph wind with something like .....(posted #11)

and about 3 stage???

Fun

( :>) Norm

windstuffnow · « **Reply #17 on:** March 04, 2005, 01:22:31 PM »

That would be one extreemly high torque machine! Driving the pinion gear to the ring gear would end up with somewhere in the 4 to 1 drive... if your in putting 40 rpm then your getting 10 out. On a breezy day there would be enough torque to drive the car you took the differencial out of! It might be better ( for generating electric ) to drive the ring gear ( mount the turbine on the wheel axel and take the power from the pinion end... 40 rpms would end up 160 rpms output. ( depending on the axel ratio of course).

Is that one of yours shadow? Definately some nice craftmanship! I have an old utility barn that really needs something like that on top even if it doesn't do alot of work... fun to watch!

Have Fun

Windstuff Ed

Ungrounded Lightning Rod · « **Reply #18 on:** March 04, 2005, 04:41:25 PM »

Yes, chain and sprocket would be better than belts, but have the pulleys and belts and if this works will go to gears and chain later.

Belts are actually pretty efficient (they'd melt or catch fire otherwise). Chains need lubrication. Chains wear out. (Belts wear out too but they're easy to find, cheap to replace every year or so, and don't wreck the pulleys, and meanwhile don't generally need adjustment after the first couple hours of running.)

If I got it running with belts I probably wouldn't bother switching to chains (pending some indication that belts would be inadequate).

electrondady1 · « **Reply #19 on:** March 04, 2005, 05:29:13 PM »

windstuff ed, you need a big vawt on top of your silo 20 feet dia. by 30 ft. should make your lights glow

windstuffnow · « **Reply #20 on:** March 04, 2005, 06:18:26 PM »

I would love to put one up there! Don't have the nads to go up there... I also have a smaller one 15ft dia (id) and 45ft tall just behind it a bit. The dome is already off that one and I've been contempating setting one up inside it. Something that could be raised and lowered with cables, a form of furling system. The big one would be quite a challenge the smaller one is doable.

Circular project ( round to it type)

Windstuff Ed

electrondady1 · « **Reply #21 on:** March 05, 2005, 07:55:38 AM »

nvmike, you certanly pushed a hot button with your posting. may i suggest you create a diary/ so there could be an on going exchange of ideas. perhaps call it the vawt club or what ever.

nvmike · « **Reply #22 on:** March 05, 2005, 08:17:31 PM »

Good suggestion Electrondady, I will start a diary.

Also would like to thank all the posted.

I gave up the belts and started using chain and sprockets today. Also took down the rip-stop nylon sails and put up 1/2 plastic buckets. Not sure which works better at this point. Hope to have the PMG on soon.

hvirtane · « **Reply #23 on:** March 06, 2005, 04:17:01 AM »

Hi,

why not making your dual alternator

with really big disks and no gearing?

If the disks are about 1 m diameter

the magnets will move fast even

if the RPM is slow.

My recent idea for a VAWT is here:

http://www.fieldlines.com/story/2004/11/29/10155/497

Comments?

- Hannu

Kevin L · « **Reply #24 on:** March 06, 2005, 06:15:30 AM »

Here's what you RPM's will look like at a given speed

As you can see your gonna over speed at 100:1

Kevin L · « **Reply #25 on:** March 06, 2005, 07:18:42 AM »

Been thinking about it and my comment was for gale force winds during storms. I just remembered my thoughts on this from last year. The loading on the windmill will not determine if its going to get damaged, and a savonious of 12 ft diam will max out below 200 RPM. Your going to have most of you power below 20 Miles per hour, I would rig up an electric clutch that kicks in around 17 to 20 MPH to disengage to windmill, or reduce the gear ratio a little if you want a little more of the higher winds. VAWT's have been my primary interest as well. I hope to try out a few of my ideas in the coming months. My largest concern with these is the creation of a giant catapult. A 12 ft diam savanious type windmill has the capacity to hurl a great amount of energy if a failure should occur in the main rotor. Of course I guess the same can be said for a HAWT but their failures generally will occur in the vertical and not the horizontal plain. I think that keeping it as light as possible is the best way to minimize the inherent danger. Have fun, and I look forward to photos and updates on your project's progress.

Kevin L.

electrondady1 · « **Reply #26 on:** March 06, 2005, 08:08:02 AM »

i like the simplicity of a direct drive geni on the shaft of a vawt but in my experiments have found it hard to generate much currant at 0-150 rpm. a large dia. mag rotor is the solution i guess but its hard to eliminate runout (wobble) when your 1/2 a meter from the center of rotation.i am a reluctant convert to a geardrive system. on the plus side of it as my generator knowlege and skill evolves one could more easily upgrade if the geni was a modular unit.

E man · « **Reply #27 on:** March 06, 2005, 06:44:41 PM »

Am I seein' things?

Look at the HAWT windmill in the background of this photo (far left). It has two rotors on the same shaft. Huhhh? Oh, well.

Not quite right,

E-man

fishfarm · « **Reply #28 on:** March 12, 2005, 01:47:23 PM »

I'm not a wind person but has anything like this been tried? Imagine, if you will (ala Rod Serling), a free spinning wind vane atop a VAWT. Attached to the wind vane are two plates on either side of the VAWT, the same height as the VAWT, and sized and angled to balance the wind loads. One plate could be shaped as an airfoil to create a negative pressure on the upwind side, with the downwind plate sized/angled to compensate for the lift. Something like this:

<

spinner · « **Reply #29 on:** March 18, 2005, 10:44:15 AM »

Have a dual-helix driven VAWT up in the air ( not in service usefully as yet, due to weather/location problems). The genny itself is a 12/9 three ph. setup, using wedge mags from Windstuff now. On a test bench the unit will put out 100+v no load (if I wanna drive it that hard!) will be tying the dual dual-helix to the gen. via a 1(helix)to 3(gen) chain drive as soon as the difficulties (above) are taken care of. The Helix unit has been up in the air all winter and seems to be holding up, so far..have not made much mention of it on this site because most people here seem to be using HAWT style setups whichI can't do because of my location.

Good Luck,

Spinner

electrondady1 · « **Reply #30 on:** March 18, 2005, 11:12:03 AM »

now i really would like to see a photo of your d.h. design if you can manage it. also the gear layout . i am about to attempt the same thing. the little geni ive built ( 10"dia. ceramic mags) produces a suitable current but only at top speed. if i can overdrive it i can charge batteries in slower winds

spinner · « **Reply #31 on:** March 18, 2005, 05:03:33 PM »

I'll try and post one that I have of the DH up in the air, tomorrow... IF i can figure out how to do it (never posted a pic. here, before.

Spinner

electrondady1 · « **Reply #32 on:** March 18, 2005, 06:11:03 PM »

just as a heads up on the photos , they seem to come out alot larger. i'm new to computors and that probably has a lot to do with it.there is also a recent diary thread going on named" vawtpostings welcome"

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Author Topic: Would like to share ideas for VAWT (Read 5527 times)