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--gt--
Newbie

Joined: 29/03/2010
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Posts: 4

Posted: 08:03am 29 Mar 2010

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Hi all, was planning to knock up a LENZ2 with F&P motor for a play.

I read that the efficiency wasn�t very good on the LENZ2 in a stronger breeze.

Does anybody have any recommendations on design changes for big winds (other than build it strong).

I was thinking maybe of trying just two wings for a start and see if it will start ok.

Cheers.

KarlJ

Guru

Joined: 19/05/2008
Location: Australia
Posts: 1178

Posted: 10:46am 29 Mar 2010

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ahh nope, if you design it for a hurricane it will never work at any other time, trying to capture big winds is pretty useless, aim for capturing whats available 80% of the time and the other 20% you'll be really happy, possibly quite scared!

Luck favours the well prepared

Tinker

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Joined: 07/11/2007
Location: Australia
Posts: 1904

Posted: 03:00pm 29 Mar 2010

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--gt-- said
Does anybody have any recommendations on design changes for big winds (other than build it strong).

I was thinking maybe of trying just two wings for a start and see if it will start ok.

Cheers.

In my experience, the Lenz2 as published maxes out on RPM in stronger winds. In other words, mine spun fast but not faster if a big wind gust came through. Alas, it was still not fast enough to reach cut in for a 24V battery bank.

I think two wings is going the wrong way.
I now have 5 wings at over twice the original diameter and a 6.4:1 gearbox driving the generator.
This survived a severe storm recently, just spinning at around 60RPM and making power.
However, since the wing size was not increased, the mill will not start in low winds at all. Next plan is making scaled up wings to get the torque for driving through the step up gear box.
Bigger diameter & more wings seems to work for me.

I should point out that my mills wings are only 600mm high and are mounted on a single (5 stud) trailer hub on angled struts.

The published original Lenz2 shaft & bearing arrangement is *very* difficult to get (and stay) balanced, wind pressure will push even a very strong frame out of alignment. Been there, done that

. Its, IMO, not the way to go for a high wind Lenz2.
Good luck with your experiment.

Klaus

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