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Forum Index : Windmills : Hi New to the forum!
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Sideshow Bill Newbie  Joined: 04/05/2011 Location: Posts: 4 |
Hello, Im new here so please go easy on me! From the UK, Ive been messing with a windmill project for the last few years, with the design brief that nothing is to be bought for it and that it must be capable of doing something useful... After having a go with rigid blade turbines, I had a bit of a brainstorm, and went to develop the Mediterian design with fabric sails. I designed a type of Bermuda rig on each of the 5 masts, similar to that seen on a sailing boat. Here is a picture showing sail layout when I had it all assembled at a festival. ( the entire week was windless!) 
To control the speed and hopfuly pervent overspeed, I have devised a centrifugal governor, whhich I eventualy hope to incorporate into a sail trimming system. The power shaft runs down the rotational axis. I use a 9" grinder gerabox to mount the sails :) The governor operates a rudder which turns the weather vane. 
I have also scratch built a semi-axial flux generator (onto a 4" grinder gearbox) but am disapointed with the power so far. Maybe its just too small? Anyway, Im looking forward to meeting you all and discussing all sorts of power generating schemes. Cheers Bill  |
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| VK4AYQ Guru  Joined: 02/12/2009 Location: AustraliaPosts: 2539 |
Hi Bill Welcome to the forum and thanks for the interesting photos, it is certainly different, looks like you got your inspiration from a old grain mill. It may be a bit slow to generate electricity in any quantity, as this type of mill id very draggy. All the best Bob Foolin Around |
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Gizmo Admin Group  Joined: 05/06/2004 Location: AustraliaPosts: 5078 |
Hi Bill Good to see you on the forum. Are you using the angle grinder gear boxes to step up the RPM? I've got a couple of those gearboxes and from memory they are about 4:1 ration, so two in series will give 16:1 The sail type windmills dont have a lot of speed, but do have good torque, so suing the gear boxes to step up the RPM will help. I would stay away from a mechanical centrifugal governor, lots of moving parts to cause trouble. Could the sails be used in some way? Glenn The best time to plant a tree was twenty years ago, the second best time is right now. JAQ |
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MacGyver Guru Joined: 12/05/2009 Location: United StatesPosts: 1329 |
Sideshow Bill Welcome to the 4m. As for your comment about things being "too small" I'm the king of building things too small here and you're absolutely right; small is just for fun but it doesn't cut it when you want real power. All my stuff is just toys and I do it mostly for entertainment. If your intention is to reap some useful "power" follow the rest of the crew's advice and make it a bit bigger. As is true in other arenas, "size counts"! I also sail and if I were going the Dutch windmill route, I'd figure out a way to luff the sail to control speed. You may be able to come up with some sort of device that yanks on the "foot" of the sail to move it in and out of trim. Sounds like a fun project; thanks for the post. . . . . . Mac Nothing difficult is ever easy! Perhaps better stated in the words of Morgan Freeman, "Where there is no struggle, there is no progress!" Copeville, Texas |
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| Sideshow Bill Newbie Joined: 04/05/2011 Location: Posts: 4 |
Hi Glenn, Yes I am using the grinder 'boxes to step up the RPM, even the 1:16 or so is slow for the generator. I find the "jib" sail stalls easily, getting the apparent wind on its rear face. This does limit the max RPM, however, better trimming of the rigging would probably help. I designed the mill with low wind in mind, as I do not have any access to a decent windswept area! The sails certainly have a good starting torque, as I found when a gust came, as I was trying to adjust one.. Took some hanging on to! The governor also acts as a harmonic damper as its geared to run at about 0.8 of the power shaft speed. I would like to improve on the efficiency of the generator. Right now it will light up some LEDs and give an open circuit voltage of some 18V is I connect all 3 sets of windings in series. Actual power is pitiful at a Watt or so! Apart from the cogging at start-up, there does not seem to be any load from the generator. I am thinking of linking up a car alternator, accepting the poor efficiency, but looking for a quick fix so I can get on with developing the sails. Hoping to have it up at Glastonbury Festival at the end of June, if nothing else it will mean the festival will be wind free :) Thanks for your inputs Bill |
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wind-pirate Senior Member  Joined: 01/02/2007 Location: CanadaPosts: 101 |
Hi Bill Welcome to the world of wind... I have found that step up methods require more wind. 
I have a four blade that runs at 450/ 500 rpm. steped up to 1,500. It requires about 15 mph/22km winds to get power out. It runs a treadmill motor righ now. 12v's 15 amps. But the brushes don't last very long "in the Elements". THE Pirate. stealing wind & solar energy is fun |
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| Sideshow Bill Newbie Joined: 04/05/2011 Location: Posts: 4 |
Hi thanks for the welcome. Mine is going for it a bit even at 60 RPM. But when the wind fills the sails it takes off like a galleon! The starting torque is good as almost my entire disc 2.2M diameter, is taken up with sail. |
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| Air Bender Senior Member Joined: 25/01/2011 Location: AustraliaPosts: 206 |
Hi Bill I can see where you are coming from with your wind mill. I have had a love of sailing since i can first remeber, and i spent 7 years living on and sailing a small coastal Bermuda riged sloop around tasmania and up the east coast of Australia solo. Now I find my self with no boat but a house a wife and 2 children. So when i get the urge to be out sailing i go and tinker with the wind mill. Looking at your photos temps me to go out and add a gib to my mill wings. All the best Dean. |
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| Sideshow Bill Newbie Joined: 04/05/2011 Location: Posts: 4 |
Here is a nice picture showing most of the workings, rigging etc.  |
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