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imsmooth
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| Posted: 08 April 2008 at 3:12am | IP Logged
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What rotor diameter works well for a standard F&P 80 series. For those who have done neo conversions, what rotor size (range of sizes) works well? Would 7' be too small? How about 8.5'? As I mentioned in a previous topic, www.tlgwindpower.com has an 8.5' rotor. I don't want to go too big because I won't be able to electrically stop the rotor if it is too big for the generator.
My other question is other than furling and electrical shorting, how do you stop the rotor in high winds? Would a bicycle braking system work? What have others done?
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brucedownunder2
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| Posted: 08 April 2008 at 6:41am | IP Logged
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Hi again ,,,
I've used various dia blade sets, . Your question is all about where you are in terms of "good" wind. If you get fairly constant moderate to strong wind ,then the blade set in the 7 to 8 feet would give you lots of rpm and therefore some very good output.
I live in an area where we get "occasional" good wind,mainly in winter, summer brings low winds. So my choice was to build a 12-13 foot set of blades (as the smaller 8 foot ones didn't want to turn 90% of the time). These bigger blades are ABS plastic,very strong, and turn my dual 80 series F&P in a slight breese,reaching cut in voltage sometimes. If the breeze picks up a bit then I see up to 300 watts,occasionally.(ceramic rotors).
So,, all in all ,Id suggest you build some 13 foot blades --.
You would be very wise to build in a braking system,I've posted pictures of mine on this site ,read back posts,search "brake" Etc.
Another point ,,make your platform where the blades spin with at least 18 -24 inches clearence from the tower--big blades will flex back a lot. thats why I have a braking system.
Any more test results of the neo rotors??.
Thanks,
Bruce
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Bushboy
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imsmooth
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| Posted: 08 April 2008 at 7:26am | IP Logged
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No more tests, yet. I got back from work a short while ago. I noticed on this site that some people have made laser-cut hubs that fit onto the star-like spline of the F&P shaft. I am wondering how I am going to fix the hub I want to get to the shaft. Does anyone here have any pieces, or at least any suggestions? Could I just use a lock-washer and nut to fix the hub to the screw-end of the shaft?
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dwyer
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| Posted: 08 April 2008 at 8:26am | IP Logged
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Hi
 There is something l might able to help you is get 1975 Totoya Corolla tail-shaft and cut out yoke approx 60 mm and is fit same size as shaft as F&P and you able to weld steel plate to suit the Blade or fabication steel plate what ever you think  if might load up picture of the yoke just let me know .
Dwyer the bushman
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MyCattMaxx
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| Posted: 08 April 2008 at 2:22pm | IP Logged
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according to flux this is the situation...lol
The F & P was designed as a motor, it is about as unsuitable a construction for an alternator as you could imagine, but it is cheap and easily available.
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KiwiJohn
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| Posted: 09 April 2008 at 4:18am | IP Logged
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MyCattMaxx wrote:
The F & P was designed as a motor, it is about as unsuitable a construction for an alternator as you could imagine, |
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It is? Why do you say that? It has a large diameter which means rapid flux change even at low RPM, it has open construction which enhances cooling, no brushes, easy to mount.
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brucedownunder2
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| Posted: 09 April 2008 at 7:22am | IP Logged
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Hi Mycat,, You mean I've just wasted over 10 years of my life . You say these things , now show us the pictures of your efforts ??
We have a dedicated Crew here on "thebackshed" to various "renewables" and may I say some of the work I've seen is FIRST-CLASS .
Come on ,,show us what you've DONE..
Bruce
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KiwiJohn
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| Posted: 09 April 2008 at 7:34am | IP Logged
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Bruce, I presume one valid criticism that could be levelled against the F&P is that of efficiency though the Dr Chalko paper does show ways to significantly improve this.
Nonetheless the one area where the F&P appears to shine before all others is the watts/$$$ ratio!
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brucedownunder2
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| Posted: 09 April 2008 at 7:50am | IP Logged
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Hi John ,, Yes, I suppose I saw red too early,sorry fatcat,
I guess it's my fiddling around with these F&P things that I like ,,hardly any cost and lots of really nice guys out there doing the same thing.
I'm putting together a test table driven by a gearbox and 1.5 hp motor. It's rigged for "dual" stators ,so I'll be able to evaluate different windings and Neo rotors.
will post some pictures when it's finished..
Bruce
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vawtman
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| Posted: 09 April 2008 at 8:16am | IP Logged
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The f@p seems more sensible to me than a simple 4pl motor conversion.
If i had one back in the day i would have done that before the Baldor.
Ive tricked Flux a couple times but very very seldom.
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Gizmo
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| Posted: 09 April 2008 at 12:03pm | IP Logged
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Hi Guys
I feel I should comment about the bagging of the F&P at the FieldLines site.
FieldLines is hosted in the USA, and the majority of its members are north Americans. Over the years the Fieldlines/Other Power site has developed their own version of the windmills built by Hugh from Scottland. If you havn't ever seen these sites, they are worth a visit, lots of great info and photos. Important thing to remember, the F&P is a very rare beast in North America.
Now the FieldLine/Other Power design is an axial flux path alternator that can be scaled to any size from a few watts to kilowatts. It works pretty good, I've built one, but does have a few problems, like the need for expensive magnets, hand wound coils, and overheating/burnout problems if not correctly set up.
Now in the Australasia region we are lucky to have access to the F&P smartdrive motor. The F&P is easy to get hold of, cheap, durable, cheap, easily adapted, cheap, and cheap. Its a comlete package, coils, magnets, all mounted in a neat little unit. And this is why they are so popular as alternators in our "down under" windmills. You dont need to make an alternator from scratch, and fact is you cant kill the things with a stick.
Its true that the F&P is not perfect. There are iron losses in the stator, so that drops its efficiency a few percent. And cogging can be a problem, but there are now several ways around this so its not really an issue anymore. But the low cost and ease of use outweight these problems in my view.
If I had a choice of using a $30 2nd hand F&P as the basis of my windmill project, or a slightly more efficient axial flux alternator with a couple hundred dollars worth of magnets, hand wound coils, epoxy cast stator that will probably burn out in the first storm, then I'll pick the F&P every time.
I do think some of the comments made on Fieldlines about the F&P not being a good choice for an alternator show a very "glass half empty" attitude. Some of the comments about iron losses do seam to be thrashed to death. Yes iron losses do rob some power, but loosing some power is better than making no power, and if you worried about every little loss you would never build anything.
Glenn
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Highlander
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| Posted: 09 April 2008 at 6:30pm | IP Logged
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Well put Glenn.
I recon the main attraction is the ease of construction.
Most of it is all done, so for anyone new it's not so daunting a task to put one together.
Especially with the fantastic instructions you've put here Glenn.
Getting more people into it is a good thing.
They're not perfect but what is?
For anyone in the greatest country on earth (Australia) these are a great option.
By the way Maxx what sort of cat is that? it looks like a bengal
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Topic: rotor sizing for F&P
