Fieldlines.com || help on 6' foot wind turbine design

Front Page - [Homebrewed Electricity-- (wind) (solar) (hydro) (steam) (controls) (storage) (mechanical)] - Classifieds - Site News
Everything - Newbies - [Remote Living-- (housing) (heat) (light) (water)] - Reviews - Diaries - Our Products

help on 6' foot wind turbine design
By olvvlo, Section Wind Posted on Thu Jul 03, 2008 at 12:10:16 PM MST
How can I modify Hugh Piggotts design to make a 6' foot turbine

I wish to modify Hughs 4' or 8'foot alternator design to work with a 6'foot rotor diameter, but not quite sure which way to go about it. My thoughts are to:

add a second disc and magnets to the 4'foot design, increasing the number of turns from 85 to 100 and a heavier wire gauge (not sure what gauge).
to use the eight-foot alternator design and increase the air gap, to enable a 6'foot rotor to run without stalling.
Or are there better ways to go about this?
Alternatively has anybody come up with a 6'foot diameter alternator design that I haven't found yet?

help on 6' foot wind turbine design | 4 comments (4 topical)

Re: help on 6' foot wind turbine design (3.00 / 0) (#1)
by Flux on Thu Jul 03, 2008 at 07:25:11 AM MST

Yes you can use the 8ft with a large increase in air gap. You would benefit from reducing the number of turns and using thicker wire with the same air gap. it would then likely stall in high winds and you would need added line resistance, which would make the alternator virtually bomb proof and you could hold furling off to probably 30 mph.

The 4ft design made dual rotor with 8 more magnets would suit your needs and would be cheaper but the 8 pole on a small disc does cramp your style at the centre of the stator if you try to use the common hub with studding separating the discs.

I have done this with the metric magnets 46 x 30 x 10 mm using 100 turns for 24v. This is used with a converter and for use direct you would do better to reduce the number of turns a bit to get a better match over the wind speed range. Probably 90 turns would be nearer.

I think I used two strands of wire in hand equivalent to 1.4mm dia. I built my own hub to overcome the space restriction at the centre of the stator, you would probably need to go for bigger discs.

I also think 12 pole single rotor with spinning blank disc would get you there well enough as the 4ft magnet disc with spinning return path will handle a 5ft 6" prop.

Flux

Re: help on 6' foot wind turbine design (3.00 / 0) (#2)
by jlt on Thu Jul 03, 2008 at 01:45:03 PM MST

I am working on a single rotor with 11inch disc and 12 2x1 1/2 mags with 50 turns of 14 g wire, coils are 3/8 thick. it has cut ln speed about 230 rpm,i have a 5 ft 2 blade prop that i am going to try on it first.the hub and bearing. are from a water pump off a car . the bolt circle is only 2 1/2" diameter.

Re: help on 6' foot wind turbine design (3.00 / 0) (#3)
by olvvlo on Sat Jul 05, 2008 at 12:04:40 PM MST

Great, thanks for your comments.
I think my inclination is to go with the alternator designed for 8' with the larger air gap if you think this will work, as six months away from now I will be moving and perhaps in a position to put eight-foot blades on.
I will probably keep the windings the same to allow for the upgrade later. Presumably by increasing the air gap alone I will just reduce the efficiency of the alternator to the point that a six-foot blade will manage to turn it.
In your experience, what size gap do you think I should allow to save me a plot trial and error?
Can you see any other problems I might find myself up against before I commit to building it?
And has anybody on the board experimented with a variable gap governed by rotor speed?

OlvvlO

Re: help on 6' foot wind turbine design (3.00 / 0) (#4)
by Flux on Sat Jul 05, 2008 at 12:51:02 PM MST

To raise the cut in with the original winding you will need a fair increase in air gap, probably 1/4" clearance either side of the stator will be needed. If this is a 12v machine it may stall unless the line length is considerable and for higher voltages it will almost certainly stall and you will need to add line resistance to get it to keep increasing power with rising wind speed.

There is no reason for it not to work and you have the option of the correct prop later.

You could get a reasonable idea of air gap needed from hand cranking to find cut in speed. You will need to raise the cut in speed to about 250 rpm for 6ft.

Flux

[ Parent ]

help on 6' foot wind turbine design | 4 comments (4 topical)

Menu

· create account
· How to use the board
· FAQs
· search the board
· Google search the board

Login

Make a new account

Username:

Password:

Total Views

118 Scoop users have viewed this posting.

Related Links

· magnet
· Also by olvvlo

You must be a registered user to post here. It's easy and free, and the link is on the upper right side of your page.
All trademarks and copyrights on this page are owned by their respective companies. Postings are owned by the poster, but may be deleted or moved at the ADMIN's sole discretion. The Rest © 2009 Forcefield.
You can Email the board ADMIN here. PLEASE include the username you signed up with!