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97fishmt Regular Member Joined: 19/04/2010 Location: United StatesPosts: 77
Posted: 08:00pm 23 Jun 2010
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A set of blades I just finished
to try out another servo motor.
I used the blade calculator and
hope to get it to cut in at about
7 or 8 mph. We'll see.
The blades are made out of cedar
11 inches at the root and 3 1/2 inches
at the tips.
VK4AYQ Guru Joined: 02/12/2009 Location: AustraliaPosts: 2539
Posted: 02:16pm 24 Jun 2010
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Hi 97
They look very nice a lot of good work there, what output are you hoping to get from them? Are these blades for the big 400v unit you showed recently? If so how are you regulating the high voltage of this unit.
All the best
BobFoolin Around
97fishmt Regular Member Joined: 19/04/2010 Location: United StatesPosts: 77
Posted: 05:49pm 24 Jun 2010
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I kind of am shooting for a compromise,
a 10' rotor for swept area but more tpr
for some of the other motors with higher
cut in rpm. This is the target motor.
So about 165 rpm for charging a 12 volt
battery.
Although this motor will be at its name
plate 33 amps at about 15 mph, I'm kinda
hoping it might work on the bigger motor,
65 amps but its cut in is around 185 rpm.
As for the 400 volt motor it will cut in at
about 97 rpm for charging 24 volt battery.
Or around 187 rpm for a 48 volt battery.
I'm not playing with 400 volts it would
be spinning at 1500 rpm.
oztules Guru Joined: 26/07/2007 Location: AustraliaPosts: 1686
Posted: 09:49pm 24 Jun 2010
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Very nice work on the blades. Some well spent time appears to have been put into them
(I reckon they deserve a better genny, but we work with what we have got)
..........oztulesVillage idiot...or... just another hack out of his depth
KarlJ Guru Joined: 19/05/2008 Location: AustraliaPosts: 1178
Posted: 12:26pm 26 Jun 2010
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OZ I woudnt have read this post had I not seen your tag on the recent posts,
I really like your answers...
"deserve a better genny"
about as subtle as a brick through the front window!
but its OK as you put it in brackets
97 fishmt
they look bloody awesome, nice work.Luck favours the well prepared
97fishmt Regular Member Joined: 19/04/2010 Location: United StatesPosts: 77
Posted: 05:18pm 26 Jun 2010
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I'm not sure why you guys think these are toy
motors. They are made for the most demanding
conditions and will easily put out 5 times there
rated amps. The one pictured weighs 70 pounds
and only cost me $40 brand new. For a ~1000 watt
genny it cant be beat.
niall1 Senior Member Joined: 20/11/2008 Location: IrelandPosts: 331
Posted: 11:13pm 27 Jun 2010
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hi 97fishmt
those blades look really nice...i suspect you enjoyed working with the cedar ,can i ask if you laminated the wood or just used solid blanks ?.. cedar seems perfect for blades although it is very expensive on this side off the pond in larger sizes
i,ve tried to make one or two from cedar and it seems to have no tendency to succumb to nature ..the bugs and fungi seem to hate the natural smell/acid content of the timber ...a bit like chewing your old cedar pencil tip doing hard maths ....not a nice memory.... .... it seems a very stable wood also beautifully light ...if they run a little extra fast a little epoxy on the outer leading edge might help...but thats just splitting hairs ...
they look very similar to Hugh Piggotts blades ...did you use his calculator ?
again nice work
Edited by niall1 2010-06-29niall
97fishmt Regular Member Joined: 19/04/2010 Location: United StatesPosts: 77
Posted: 05:43pm 28 Jun 2010
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Hi Niall,
Yes I did laminate some cedar boards together.
I used the warlock calculator just to get an
idea of what size and shape would work for my
different motors.
They didn't come out like the specs on the
calculator because I just used what I had,
but they came out real nice.
I can buy clear cedar here in the Seattle area
for the tight knot price if I search through
the piles of lumber at the big box stores.
I also made a blade set out of pine. The cedar
is much nicer to work with. I'll have to start
looking for some more nice boards so I'll have
it for a 14'er or 16' rotor. My largest so far
is 12' it was to big for my old tower. The new
tower only has a stub on top that will handle the
10'er. I only got the tower done last fall. It
works well so, adding a 10' or so stub on top will
be easy.
I'm going to try things out this week. I hope
I'll get some wind!
GWatPE Senior Member Joined: 01/09/2006 Location: AustraliaPosts: 2127
Posted: 12:37am 29 Jun 2010
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As a motor, these units can consume up to 5x the rated amps but this is not the case with output current as an alternator.
I agree they are good as a motor, in demanding applications, as I have 2 of my own[not as a windmill though] as an ornament on the shelf.
Not sure how the new price is so low, as to buy new in OZ, these would be many ,000's for this size unit. My 1.6kW units were $2,000 ea, in 1993, with speed controller.
As OZtules cas commented, you work with what you can get. I try and work with what I can make. Not sure about making magnets though :)
Gordon.
become more energy aware
97fishmt Regular Member Joined: 19/04/2010 Location: United StatesPosts: 77
Posted: 01:17am 29 Jun 2010
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Hi Gordon,
In the US they are changing them out for
more efficient motors (the new neo magnets).
I am able to get the new ones as well as the
older technology (I think you said cobalt magnets)
for new old stock off the shelf. Maybe they don't
know they paid $10,000 for a motor and are just
liquidating a business. They sell them for what
they can get I guess. I just can't see them go for
so cheep so I bid on them and I get a few here and
there.
I have a 18kw unit I paid $50 for waiting to go up.
My new tower will enable me to test all these motors
with different props and hopefully get you some numbers.
I only go for the newer ones now because they are about
half the size and weight for the same power output.
If I can't lift it I don't want to deal with it.
I suppose I'll be looking for more tower sections
to get another one up instead of just making one
large turbine. My winds are mostly lite, but some
fierce ones come often also.
Notice. New forum software under development. It's going to miss a few functions and look a bit ugly for a while, but I'm working on it full time now as the old forum was too unstable. Couple days, all good. If you notice any issues, please contact me.
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.... it seems a very stable wood also beautifully light ...if they run a little extra fast a little epoxy on the outer leading edge might help...but thats just splitting hairs ... 
