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Glass fiber blades

PostPosted: Tue Apr 28, 2009 11:36 am
by aero energy
Our company manufactures glassfiber windturbine blades
for 1kw to 10kw windturbines.
One of our customers is: www.winglette.com

We are interested to sell our blades via this website.

kind regards, Nico van Meurs 083 257 4241

Some pictures attached.

Re: Glass fiber blades

PostPosted: Tue Apr 28, 2009 2:07 pm
by windgat
Do you have standard designs, or do you custom design for windspeed and desired rpm?
Could you tell us prices for 800mm to 1500mm blades?
Finally, how much would shipping to any place in South Africa be?

Re: Glass fiber blades

PostPosted: Tue Apr 28, 2009 9:09 pm
by aero energy
Our blades are designed to have a wide operating range
and will perform relatively well on any generator.
Our main design objective is to perform well at lower
windspeeds (2-5m/s).
We currently only manufacture the blades shown in the
pictures. We can design and manufacture a customer
specific blade but that would be a fairly expensive
exercise. The 1.5m blade (shown in picture) is our
smallest blade. We have no intention to design or
manufacture any smaller blades.

Price for a set of 3 blades (these are retail prices,
we will give significant discount to larger quantities
or potentially interesting projects):

1.5m blade (~1kw): R8,000
1.8m blade (~2kw): R9,000
1.9m blade (~3kw): R12,000

Shipping from Potchefstroom (where we are based) will
be around R1,000 per set.


Aero Energy
Nico van Meurs
nicovanm at hotmail dot com
083 257 4241

Re: Glass fiber blades

PostPosted: Wed Apr 29, 2009 12:27 pm
by aero energy
Forgot to mention that VAT needs to be added to all prices.

Re: Glass fiber blades

PostPosted: Wed Apr 29, 2009 11:04 pm
by windgat
Thank you.

Can you mention the specs of your blades, e.g. rpm vs wind speed, TSR etc? Also, do you have a drawing of the spacing of root mounting holes?

1.8m blade specs

PostPosted: Thu Apr 30, 2009 10:40 am
by aero energy
For our 1.8m blade (3.6m diameter):

1.5m blade specs

PostPosted: Thu Apr 30, 2009 10:55 am
by aero energy
Only power curves.

1.9m blade specs

PostPosted: Thu Apr 30, 2009 11:06 am
by aero energy
Holes identical to 1.8m blade.

Re: Glass fiber blades

PostPosted: Mon Jun 15, 2009 11:33 pm
by windgat
Could you please post a diagram of your mounting holes for the 1.5m blades?

Re: Glass fiber blades

PostPosted: Tue Jun 16, 2009 9:57 am
by windgat
Would this be right?
hubaero1.5.png
hubaero1.5.png (7.77 KB) Viewed 14656 times

And what material and thickness would you recommend for the hub?

Re: Glass fiber blades

PostPosted: Thu Jun 18, 2009 9:37 am
by aero energy
The mounting would need to look more like this.
I am aware of people using a 8mm thick steel plate.
That sounds pretty solid to me :)

Re: Glass fiber blades

PostPosted: Thu Jun 18, 2009 11:05 am
by windgat
Ok, I changed it based on that diagram. A catch I must work out is that the blades would overlap the hub mounting bolts, as shown.

Steel plate sounds heavy! I have used GRP reinforced 12mm marine plywood to date. What is your view on that?

Re: Glass fiber blades

PostPosted: Thu Jun 18, 2009 12:07 pm
by Greystoke
Years ago (as in jonks ago) I spoke to a professor on the subject of glasfibre reinforcements for helicopter tail blade mountings.
He said that you can't use an ordinary glassfibre weave to reinforce the mounting bolt holes. What you need to do is to pre-drill a template and then re-inforce the bolt holes by wrapping glass rovings around the holes. That way the holes are properly re-inforced in radial directions, and they won't shatter easily.

Holes and Hub

PostPosted: Thu Jun 18, 2009 2:14 pm
by aero energy
1. The holes

Unfortunaly we can not easily shift our holes easily. We are
using a drilling-jig for that and moving the holes would
require some modifications to that jig. Its not impossible
but it would probably take us a few months.
The part of the blade interfering with your bolts is
completely solid (wood) and one solution is obviously just to
create a small gap in the blade with a drill. There will
be little consequences from a strength point of view.
You might just have to protect the wood with some
resin or decent paint.

2. Hub plate

We are a bit new to the home-built market.
Our regular customers like to overdo things
because things keep breaking if they are too
weak. 12mm re-inforced plywood sounds
solid to me but we have no experience with it.
Try asking Hugh Piggott or maybe Paul Marais?

Re: Glass fiber blades

PostPosted: Thu Jun 18, 2009 2:28 pm
by windgat
How about if I mounted the blades an extra 20mm out from the centre? Would that throw out the blade aerodynamics?

Otherwise carving a bit off the root as you say shouldn't be hard.

For the hub, perhaps I'll put a second plywood disk on, i.e. making a sandwich (with ply as the bread and the blades roots as the peanut butter).

Re: Glass fiber blades

PostPosted: Thu Jun 18, 2009 3:38 pm
by aero energy
Blade aerodynamics would not be affected.
In fact you performance might just get a bit better due to increased diameter.
You just need to make sure there is enough material clamping the blade.

About the plate. I was already assuming you were using 2 plates :)

Holes

PostPosted: Thu Jun 18, 2009 5:11 pm
by aero energy
I just had a good look at our drilling jig.
We can shift our holes about 10mm towards the root.
Would that be enough?

Please try to reply today. We need to start
working on those blades by tomorrow to make sure
they are ready by next week.
I have just tried to call you to discuss this.

Re: Glass fiber blades

PostPosted: Thu Jun 18, 2009 5:44 pm
by windgat
I'd say keeping it standard is best, to avoid possible confusion in the future. I will make a hub to match your holes.

Re: Glass fiber blades

PostPosted: Thu Jun 18, 2009 11:19 pm
by windgat
Ok, here is an updated drawing of the planned hub, for your (hopefully) approval.
hubaero1.5.png

Now I just have to work out how to make these holes accurately in the ply!
Is there a process you recommend for aligning the blades accurately before tightening the bolts? Presumably there is a little play with just two holes...

Tip distance

PostPosted: Fri Jun 19, 2009 11:43 pm
by aero energy
That drawing looks excellent to me.
Just wait until next week before cutting it :)

You brought up a good point with regard to alignment of the blades.
Its absolutely critical that the angles are 60 degrees.
Just before tightening the bolts you would need to measure
the distance between the bladetips and make sure they are all equal.
Anything less than 2mm is acceptable. Anything more will
vibrate your tower to pieces.

Re: Glass fiber blades

PostPosted: Sat Jun 20, 2009 8:09 am
by windgat
Thanks aero. When I have tried measuring tip to tip before I found it very hard to be consistent w.r.t. a point to measure from. Interested to hear if you have any 'tips' for that...

I now use a hand held laser aligned over the diameter of the hub, and then mark a point near the tip. I measure the distance from the leading edge to that mark, and repeat that mark on all the blades. Then its relatively easy to check all the blades are consistently mounted. I can take a photo next time and post in case the above is not clear.

Re: Glass fiber blades

PostPosted: Sat Jun 20, 2009 12:03 pm
by windgat
Hi Aero. I am trying to plan a generator to match your 1.5m blades, so I need the power curves. I see under "1.5m blades" above you posted a graph, but the graph is title "1.9m". Do you have anything for the 1.5's? I understand its a whole process to measure, but do you have at least the theoretical curves? If I test your blades on a generator that is badly mismatched to the blade power curves, the results will not look as good as they should.

1.5m curves

PostPosted: Sun Jun 21, 2009 4:49 pm
by aero energy
I am confused by your post. Under "1.5m blades" I see only one graph
containing the 1.5m blade curves. The graph name is "AE 3.0m.jpg".
The graph title is "Aero Energy 3.0m". What am i missing?

Re: Glass fiber blades

PostPosted: Sun Jun 21, 2009 5:32 pm
by windgat
Aha, it is me who was confused! I thought that was 3m radius, but I get it now.
I have tried to read values off that graph but its a little inaccurate. Could I see the source data? What I am after is the maximum points of each curve, which I would then use to select an appropriate generator configuration for your blades.

PS: Did you see my post (above) about alignment?