Using CNC to make windmill blades.

[Matrix1000]

Anyone have any experience making blades with a CNC machine?  

Seems the local shops think that it might take around 2 hours to make one blade at $55 an hour (plus $100) for programming.

I've found some CNC machines that you can build yourself and use your PC to control them but the parts alone cost $4000 or more.

[mkseps]

Suggestion:

Look up used industrial machines in your area.  There are many used machines available that have lost their accuracy from a life of cutting steel.  Wood to a machine like this is a piece of cake.  You should be able to find a useable machine complete with software and on-board computer.  Just be sure that the machine has the table length and spindle RPM you need for cutting wood, aluminum or plastic.  Also, keep an eye out for machine auctions.

Gene

[precisiontek]

A CNC Machining center would do an excellent job on a blade.Due to the nature of the blade shape however any machine you use will probably require 4 axis movement.These machines run in the 100K+ range.If you have found someone that only charges $55.00 an hour for a 4 axis machine then you have found a deal.I have been in the CNC machining buisness for over 25 years,I now own a small shop.Our CNC labor rate runs 100.00 an hour.

Good luck!!

[Matrix1000]

I'm wondering if I paid someone to program in the basic blade design then the machine could cut the top side, flip it over and cut the bottom side and then I cold do whatever would be required to finish it up.

In your estimation how hard would it be, or how much would it cost, to program a 3 axis machine to do as much of the job as it could.

Thanks!

[farmerfrank]

Where's the pride of handcrafting gone? If you want quick and simple just buy the machine on ebay.

[precisiontek]

What are dimensions on your blade?  What size is the raw stock?

If you only want the basic 2-D profile done it could probably be done on a conventional 2 axis machine.

[Matrix1000]

39 inches long 2x6 cedar stock.

Station Radius Blade Angle Chord Thickness Drop

1.         6         12      5 ½    1 ½     1 ½  
   
2.        15 ½       12       --    .88     1 ½
   
3.        23 ½       6        --    .61      ¾
   
4.        31 ¼       4        --    .46      ½
   
5.        39         2        2 ½   .37      ¼
   

[wdyasq]

I actually CNC cut 3D stuff - Including several sets of windturbine blades with a 3 axis machine.  If your programmer can't do it- I suggest a new programmer - not a $100K machine.

Ron

[Matrix1000]

I'd like to make 3 sets of blades to start with.

How long do you estimate it took to rough cut 1 blade.

You wouldn't by chance have the CNC file you used to make your blades still

[pyrocasto]

I dont, but we're getting a nice 4-axis soon and hopefully I can produce some. Dont expect to get off cheap though man, since it's not a cheap way to do it. The machines are EXPENSIVE, and therefore you will have a high price.

[Motorhead]

Hello Fellow enthusiasts...

I have a CNC machine shop and a extensive background in composite fabrication.

Some of the work involved developing a high speed molding process for large turbines with Sandia and private investors,so I have the practicle experience of actually producing large foils.

I've seen companies formed just for the purpose of creating FRP or GRP turbine foils for commercial use. The problem as I see it is they just don't seem to fit whatever we are building.(small scale or the 1-10kw range)

I've seen the hand formed wooden foils and I'm impressed by the crafsmanship that is out there. Many people here on the board can construct the generator in some form or fashion but can't be as creative in fashioning the foils for some reason, or vice versa.

I would like to gather a group of you from this board to produce a mold of reasonable size (1-10kw)that all wind power enthusiats could purchase if they opted to forego hand crafting, all are welcome and I'm willing to work with any one who has the ability to see the job to the finish.

Best Regards

Motorhead

[Matrix1000]

Thanks for your post!

I'd like to find a 'good' 'general' blade design and have a bunch made.

The only thing is it would be nice for the 'blade experts' here to suggest a good 'general use' blade for an 8 foot dia axial flux mill. (and post its dimentions)

The only thing you can 'buy' at an affordable price are these thin plastic blades that don't work so hot for a regular 8 foot axial mill.

I'd be willing to pitch in a a bunch of cash to get the design made / programmed and set up and have a bunch made up.

If anyone is interested email me at...MatrixNetworx@hotmail.com

[cncmech]

Interesting thread, I have only been here a week trying to digest all the good info here. But you have motivated me 3 days ago to draw up a blade design. Will it work? I have know idea. I have no clue about blade design, but it will be fun testing it.

 It is a small 3 blade (15 inch per blade) for an RV. Will try to cut it this weekend and post pics.

Thanks for all the good info here and keep it coming..

[Experimental]

      It,s a lot easier than that, and I have traced a prop blank in a simple milling machine -- But won,t go into that !!

      If you look in some of the older aircraft (homebuilt) magazines, look for an add, for a propeller duplicator --- this is a simple wood box, running on four wheels -- A wood router is mounted on this "box", with a counterbalance and a "finger" made of a wood dowel, the same diameter as the router bit...

     That finger, follows the contures of a broken, or hand built prop blade, with the new blank lying next to it-- the dowel, controls the router and roughs out the new blades -- each new blade is nearly perfect, as the same pattern is used for each !!   The wheels are running on angle iron "Tracks", screwed down to the base, allowing the "box" to roll back and forth , with the router and guide finger hinged to follow, up or down, right and left to mill the blank !!

     Plans used to be offered for this unit, and as I have used one, I can tell you , it works VERY well, and is very easy to build...

    The prop will be rough, and easily finished out with a light wood file, and sand paper--- If I can find it in some of my old books, I will put it on this board

but i am leaving on a trip soon, so may not get it done untill I return!!

    This is a very easy, and inexpensive way  of building prop blades and much easier, than cleaning up my milling machine again !!!

    If I can,t find that add, I will draw up a plan for it -- it really is simple,  Bill H...