Wind Turbine Blades

[Dozzer7]

I'm in the process of building a couple of 17 ft diameter wind turbines and not being a craftsman when it comes to wood, my thought was to find a local person that could program my blade into thier CNC router from sketches that I have and simply flip the switch and bing boom bam blades would be flying (pun) from the machine.
I soon realized from the looks that I was getting that I must have a third eye or a horn growing from my forehead.
So now I throw myself at your mercy and ask, how does a person get a 8 1/2 ft turbine blade machined from vertical grain doug fir? I have the wood and will bond the pieces together. I have a fairly good idea of the shape and can describe it to someone that understands the machines langage. I have spendt several hours in the yellow pages and called a lot of shops without sucess. I'm in the Medford Oregon area.

[Larry83301]

First, have you looked at making the blades your self? Here is a link for a DIY 10' blade that is easy to follow ( http://www.otherpower.com/trips3.html ) just scrool down the page and there is a step by step on making the blades that you should be able to follow. You could just scale it up to the size you want.
Having them made on a CNC will require not only a CAD drawing of the blade that you want built, but also a shop with at least a 10 foot CNC mill with a fourth axis. Also hope that they have a low shop rate as this large of a blade would take many hours of machine time.

[Khalid]

No.. we can make those blades in slices... (I have the wood and will bond the pieces together.). So afetr accurate CNC contouring in pieces.. he can join them easily..

CUT3D software from vectric can work on sliceing the object in desired pieces...

[thkoutsidthebox]

You don't even need slices, never mind the 4th axis, if the Z movement is sufficient. Simply carve one side using index pins, flip it, and carve the other. "Bing Boom Bam" as the man says!

Regarding the original post, cnc machine code works on numeric values for the X,Y, & Z (On a 3 axis machine) co-ordinates for the cutting tool at any specific time. The machine simply moves the cutting tool from X1 to X5 back to X1 and on to X5 again (Or whatever numbers and axis)...back and forth, or up/down, or left/right over and over again etc etc etc. After doing this hundreds of times, each move being only a fraction of the tool diameter away from the previous move for a 3D piece, you have carved your required shape. Thats a VERY basic description....

....anyhow, basically for the machine to do this, involves various processes to create the code for the machine. Some more or less complicated than others. In your case you have sketches and can describe the blades, but this means diddly squat to a hunk of moving metal .

For the people you are contacting to carve your blades, they will have to take your sketches, turn them into computer graphics in a CAD program, which will take at least a few hours, not including referring back to you to check they are correct later (Possibly to scale depending upon the later CAM program), they will then have to run these through their CAM program to generate the previously mentioned code for the machine (To scale) from the 3D CAD graphics. After that they will have to index your pre-prepared lengths of wood, (the size of their machine, the number of zxis, and the complexity of the blades will affect how long this will take) and then press the bing boom bang key. Then they'll have to come back at various intervals a few hours apart to re-position your piece as necessary for the other side/s and such. Then they can give it to you to finish sand and coat.
For all this your looking at costs for labour, machinery wear, consumables etc which adds up to $$$.

So how does this help me you ask? Well....it doesn't really, but now you know what's involved when you ring someone to carve these for you. They probably don't seem interested because they know how much it'd cost...and that you dont!

Here's what I can suggest:

Post a 'Request For Quote' on this site. Specify that cost is a major factor and your looking for someone who would be willing to carve these for the fun and experience. There are lots of semi-hobby guys here who have tables big enough and might like to do it. I'd offer myself except my table is too small and I'm 3000km away!

Find a friend or someone who's willing to generate the CAD drawings for you so that at least when you call places you can tell them you have the CAD drawings already done and you just need them carved. Possibly check with some of the places you rang if they'd be interested in the job if you can provide them with the CAD drawings, and if so check what format they would want them in.

Find a another/same friend or someone who can not only generate the CAD but can then generate the machine code.
If you find someone who can generate the machine code, then there's a....ahem...100% possibility that they have a machine , if its big enough get them to carve the blades.

Keep asking around, call some of the places again and explain to them that you know whats involved, but that you still want this done. Decided on your budget before you call and start getting quotes. If you get a 'nearly there' quote, call again and ask what you can do to bring the price down within your budget.

I can't really think of much else. Finding someone willing to just help you out is probably your best bet, but commercial shops in the phone book have expenses and overheads to consider, you need the guy next door with the 8x4 table in his shed....he does exist, you just need to find him.....

[spoiledbrat]

I might be able to help. I can model and tool path your propeller using Rhinocam, and output some G-code for most machines, no problem. This, of course, will require coordination between me and the person that owns the router you will be hiring. However...

I do not have a 4 x 8 foot router, I have a 2 x 5 foot router.

I know people that have large machines, and good grief they are fast. With the correct choice of tool paths, and a machine that can make light cuts @ 800 IPM, I believe your project could be boiled down to 8 hours or less machining time (for a three blade turbine). Planning on $100/hr machining time, with 1 hour setup/flip-the-wood time, you could be looking at less than $1000 machining time. Plan on doing some belt sanding.

I did use my machine to make a prop for a buddies airplane. My machine is considerably slower than a commercial machine.

pm me if you are interested in getting this model created.

[ViperTX]

spoiledbrat....thank you for putting some reality into a vision.

Personally, it would seem that with all the surge in wind activity.....used and surplus blades would be plentiful.....but alas....I suspect they are much larger.

Dozzer7....check the threads with Mr Bean.....he was doing his own wind energy blades...

[BCwanderer]

I have an interest in blades as well
I bought DesignCad 18 $(150) which works with ContourCam ($100)to drive CNC tables
I laid out an 8 foot blade in DesignCad.
It is only partially constructed.
Here is a link to an article about S222 blades
http://wind.nrel.gov/designcodes/pap...or%20HAWTs.pdf
http://www.nrel.gov/docs/fy99osti/26173.pdf

Here is a Zipped copy of the stations of the blade laid out 8 foot long with S222 airfoils in Designcad format
The blade is set up for a TSR of 6 with the hub squared up.
If it was mounted on a 1 foot radius hub, the blade would be about 8 1/2 to 9 feet long.

If you can figure out how to skin it properly, ContourCam is supposed to be able to cut it out.
You can get a Designcad demo for free at
http://www.imsidesign.com/Products/D...1/Default.aspx
ContourCam is available at
http://magicsystems.com/usa/default.asp $100

I have no connection with ContourCam.
I would love to see if someone else can get it up and running

I am still working on my 10 foot table so I will be a while before I cut chips on a turbine blade.

[BCwanderer]

Here is the 8 foot S22 blade skinned in Designcad
It is skinned in two sections due to the limits of Designcad
FYI

[High Seas]

Thanks for sharing the s22 blade - could you export that as a dxf, 3ds, or stl for other CAD systems?
TIA - Jim

[BCwanderer]

Here are zipped files showing the S222 (lookalike) blade profiles resized and angled for different stations of an 8 foot radius wind turbine blade.
The numbers on each file indicate the distance from the hub of the turbine for each station.
Close to the hub, the profiles are altered to fit the wood I am looking to use.
The Corel files each show the original profile and the angle of the blade is noted.
I used Corel Draw to manipulate the profile.
The DFX files are the bare angles profile at each station.
If you use the DFX files directly, they have the pitch already calculated for an 8 foot blade. You could probably stretch the blade to 10 feet and it would still be very close to the correct angles
There is a centering cross on each profile that shows the centre of the original plot. You can use that to assist if you wish to taper the wing back or place the stations straight.

There is a Corel cdr file of the S223 profile as well but I did not use it.

If these are any help to anyone please post your experience.

[BCwanderer]

Here is an autocad DWG exported from DesignCad
I don't know how true it will come out.

[Glidergider]

Dozzer7,
Have you ruled out a fiberglass/carbon skinned blade? It would be considerably lighter, and thus your suspended and spinning mass would be reduced. Lighter blades would mean less wobble and balance problems. Less friction on the bearings too.

Cut a mold for the blades and you can make multiple copies. I know this is a skill that you may not want to learn, so ignore this comment as you see fit.