Author Topic: How can I furl an Ametek 99v mill?  (Read 3466 times)

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Scott

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How can I furl an Ametek 99v mill?
« on: June 18, 2017, 09:48:31 AM »
I've lost 2 mills lately in big storms, but I admit I'm over bladed on the Ametek.  It's been putting out 15 - 20 amps at 12v in good winds.  This is at my off grid camp and it's a very windy site with a 65' tower on the NE edge of a lake that funnels the prevailing wind right to me. 

I lock it down when I leave but the blades have so much torque they can still spin the motor pretty hard.  I either need to put a rotor on it that is better matched and won't fly apart in high winds or come up with a furling setup.  Any ideas?

Along with my mill I also lost 2 of my favorite Helmocks in a storm this past March.


Gordy

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Re: How can I furl an Ametek 99v mill?
« Reply #1 on: June 18, 2017, 11:13:03 AM »
Scott,

I just entered "furling" in the search box and got 38 pages with 30 posts per page as results of the search.  A lot of reading ;-)

I doubt you'll find a simple answer, as all mills are built differently enough as to need the furling system to be customized to the mill.  Furling is to me a little complicated. You need to calculate the blade diameter, the amount of offset between the center of the generator head and the pivot point at the top of the tower, the wind speed you want it to start furling at, ect... Then the size and weight of the tail can be calculated. I remember in the past there was a lot of trial and error involved in getting some mills to furl properly.

Good luck,
Gordy

Scott

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Re: How can I furl an Ametek 99v mill?
« Reply #2 on: June 18, 2017, 02:54:47 PM »
Yeah Gordy I've been searching and reading, haven't found yet where someone has furled a small pma like I'm using.  Was just hoping maybe somebody had done it.  I've been using these Ametek motors for almost 20 years and only recently lost 2 in violent storms.  I really don't even need it in the summer, I've got plenty of solar, it's wintertime when I have to have a mill up. 

I think I'm just going to get some steel blades from windynation or tlgwindpower and short it when I'm not there.  I've been using some old Southwest Windpower blades from one of their big turbines but they're just too much for these motors.  Also thinking of coupling a 99v and a 72v together  :D 

I went out there today to drop the tower and pull what's left of my mill, it even bent the top of the tower, dang, that was a hell of a storm.




Fused

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Re: How can I furl an Ametek 99v mill?
« Reply #3 on: June 18, 2017, 03:45:27 PM »
Maybe consider building a tilt up machine?
There are people making and selling tilt up turbines
but I forget where I read it. Search furling and look at the pictures,
its in there.

Doug
System specs: 480 watts peak solar, 8- 6v duracell batteries at 24v controlled with tristar 45,, wind generator is axial flux
with 5 foot blades

if good guys don't carry guns, only the bad guys will.

Mary B

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Re: How can I furl an Ametek 99v mill?
« Reply #4 on: June 18, 2017, 08:23:14 PM »
I have seen people make a mount that offsets the gen head from the pivot to make it turn out of the wind. Not real furling but it will help. The mount on the bottom is for an F&P but could be adapted for the Ametek. Maybe use the shaft to drive it via a chain so the bearings in the motor are not taking the load...http://www.randysworkshop.net/products.html

Gordy

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Re: How can I furl an Ametek 99v mill?
« Reply #5 on: June 18, 2017, 10:07:31 PM »
Scott,

OUCH on the tower :-(

Been doing a little snooping on furling, have you read this post?  http://www.fieldlines.com/index.php/topic,149071.0.html  I think you will find it interesting, a lot of info there you need to figure out what I was talking about before.

Gordy

Scott

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Re: How can I furl an Ametek 99v mill?
« Reply #6 on: June 18, 2017, 10:32:03 PM »
Thanks for the replies but after 20 years of playing with windmills I've decided I'm done and just going to go straight solar.  I've truly loved making power from the wind, and I have the perfect site but honestly my power needs at my camp are very small.  I have all LED lights, one LED tv and a cell booster and that's it, no water pump or anything else, it's all 12v.  My main reason for wind power was for the winter when there's little sun and lots of wind, but even then my I can get by with solar, and I have a gas genny in the shed if I really need it.  It's the end of an era but lately it's just been way too much time and effort to keep it running.  I'm kind of sad about it but I just don't have the time to keep running out there to dink with it. 

Adriaan Kragten

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Re: How can I furl an Ametek 99v mill?
« Reply #7 on: June 19, 2017, 02:27:06 AM »
In my free public report KD 485 (see website: www.kdwindturbines.nl) you find a general description of several ways how the rotor of a wind turbine can be turned out of the wind at high wind speeds. In the reference of KD 485 you find the KD-reports in which every system is described in detail including the moment equations.

Scott

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Re: How can I furl an Ametek 99v mill?
« Reply #8 on: June 19, 2017, 11:06:42 AM »
If I could manually furl it from the ground that would be all I need.  I could run a cable down through the tower and if I could pull the tail in 90 degrees when I leave camp that would work.  I don't need to leave it running when I'm not there. 

Adriaan Kragten

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Re: How can I furl an Ametek 99v mill?
« Reply #9 on: June 19, 2017, 12:59:16 PM »
Even if you are at home, you can be too late to turn it out of the wind manually. The wind speed can double within 10 seconds because of turbulence. Especially during thunder storms you can have very strong wind gusts. Any safety system should work automatically, steered by the rotational speed or by the rotor thrust.

kitestrings

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Re: How can I furl an Ametek 99v mill?
« Reply #10 on: June 20, 2017, 09:17:18 AM »
Scott,

You may have seen this, but this is a related project that we undertook.  Prior to installing the actuator we just used a small hand winch.  It worked perfectly fine.  I would highly recommend this dyneema (sailing applications) rope/cord.  Ours IIRC is 4mm with a working rating of some 1,200#.  Very light weight and almost no stretch.  Cable, which we had years ago, is comparatively a real pain and much heavier.

http://www.fieldlines.com/index.php/topic,149230.0.html

The furling operates independent of the winch, or actuator, which solves the problem Adriaan is describing.

Good luck, ~ks

Scott

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Re: How can I furl an Ametek 99v mill?
« Reply #11 on: June 20, 2017, 09:28:42 PM »
You guys are really good and do some amazing things but my system is small and very simple and I really want to keep it that way. 

I'm powering a remote off grid cabin on a little lake and I run 12v for everything, have some 6v golf cart batteries, a Xantrex C60, 240 watts solar and my little 99v Ametek mill.  I only go there maybe once a month for the weekend and in the summer I don't need the windmill hardly at all but I do in the winter for maybe 4 - 6 weekends. 

All I'm looking to do is manually lock it down/furl until needed.  If it gets complicated I'll pull the tower and add more solar, which would obviously be easier, but I've thoroughly enjoyed playing with windmills all these years and there's a certain satisfaction of watching my analog meter bounce around when the wind's blowing. 

kitestrings

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Re: How can I furl an Ametek 99v mill?
« Reply #12 on: June 20, 2017, 11:05:02 PM »
The "Rutlands" had a small hole in the tail vane presumably for a sailor/owner to hook it with a small pole and turn it out of the wind.  Your's look to be a bit high for that sort of thing  ;)

I wonder if you could fashion a small brake on the back of the hub, or perhaps hinge the tail vane off the tail boom so it could be pulled from the ground with a line?

best, ~ks

coldspot

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Re: How can I furl an Ametek 99v mill?
« Reply #13 on: July 20, 2017, 02:40:49 PM »
What would be wrong with the standard gravity furling ?
I've used that on my 20V Ametek for about 10+ years now.
 Offset mounted the direction the blades turn towards.
And a short out plug when I don't want it to be working.
 Just saying.
$0.02