Carving Wood Blades

[DragonFly III]

I am definitely not a wood worker.  I can rough things out and then have someone else do the finishing (or at least I wish I had someone to do the finish work). 

I like the Idea of carving my own blades but would it possible for someone like me to accomplish this feat.

I'm staying light on the details cause I would like the questions for info to come from you.  I really don't know where to start.

[SparWeb]

I am definitely not a wood worker.  ...  I really don't know where to start.

Hugh Piggott's site is full of how-to stuff on carving, any diameter you want.   www.scoraigwind.com

If you don't do it yourself, you're missing half the fun!!!

[97fishmt]

I agree with Steven

Carving blades is the fun in my turbine
building process.

I just finished my 4th set this month.
What a month or year for progress.



I made these a little to thin to try and gain performance.
When I got to the root at the trailing edge it is paper thin.
I may paint on some fiberglass resin in this area today
and see if that will stiffen it up.

If you want it to go fast, get an angle grinder and put a
flapper disc of 36 grit on it, and then finish up with a
belt sander.

Anyway lots of fun
Mike

[defed]

i was leery of making my blades too.  it was actually not too bad once i found something that worked for me.  i intended to rough them out w/ a draw knife, but when i couldn't find my sharpening stones, i changed methods.

after making all of my marks, i took a hand saw and cut across the face of the blade, just above the marks.  i tried to cut carefully so it was flat and even across so i could use the cut as a guide.  i made these cuts every inch or 2 down the length.  then i took a chisel and and hammer and, starting from the tip, knocked the pieces of wood out between the cuts.  after this, i took a spokeshave and just shaved it down.  i wanted to stay just high of my marks and final sand down to the level, but i always got carried away and shaved to the mark.  the spokeshave made much faster work of this than i expected.  after the front was done, i repeated on the back, and carved the airfoil w/ the spokeshave as well.  the trickiest part is near the root where the blade tapers rapidly back to full thickness, but after a little trial, i found a decent way to do it.

the 1st blade took maybe 2 hrs...the other 2 took an hour or less each.  these were only 2' blades tho.  they are working pretty good too.

i'm STILL leery of making 5' blades, but i'll probably give it a go.

[DragonFly III]

I have a feeling this is where my windmill is going to lack.  I could probably carve one good blade but not three that match

[defed]

mine aren't perfectly matched...but it works fine.

[DragonFly III]

Defed,
That's in couraging.  So as long as they are close and balanced it's OK.  What about when you go larger size.
If I want 3' blades how wide should they be?

[defed]

mine are only 2' each (4' diameter), so not sure if it gets easier to go bigger.

width depends on overall size.  mine are 5 1/2" at the root and 1 1/2" wide at the tip.  check Hugh's site posted in msg 2 for details.

[SparWeb]

If wood really isn't your thing, you could consider fiberglass.
It takes a few more steps - plug, mold, lay-up, cure...   but once you're set up the repeatability is nearly perfect.
And the surface finish is excellent if you work at it - much better than bare wood.

[DragonFly III]

So as for the fiberglass blades, Do I carve one wooden blade and then make a mold?

[taylorp035]

I make mine just like defed.  I use a draw knife to cut the large bits out, then I use the spokeshave for the smaller parts and the airfoil.  A sawl-saw and a chisel make quick work near the root.

I once made a blade set out of maple, and I only used a chisel.  Then I made the hub out of hickory, and I think the wood was harder than my chisel .

Assuming that you have never made a set before out of wood, I would make sure that you choose a softer wood.  There are many ways to cut wood, it all depends what way you like most.  Some like to use a lot of power tools, like band-saws, power planers, and belt sanders, but I like to use all hand tools.  I even some times use a handsaw to make the long cut to make a board and then hand plane it myself.  

As for evenness, I think if you start with 3 boards that are all the same dimensions, you will be far on your way to making even blades.  I know some of my older blades were not even, and they performed quite well.  I once found a blade that had a 0 degree pitch at the tip, so it wasn't doing anything

A few minutes sanding should take out any rookie mistakes.


Here is a link to my current project.  I have a few pictures that should help you, particularly the airfoil picture.
http://fieldlines.com/board/index.php/topic,143760.0.html

[scoraigwind]

I had to teach myself to carve blades but I found out that I could do a good job after a bit of practice due to being highly motivated.  The best hint I can give is to make sure that your tools are very sharp.  That really helps to reduce the work and make it more accurate and neat.

If you choose to make blades from fibre-glass then take great care with the structure.  In my experience they usually seem to fall apart unless they are very well made.  It's a strong material but it needs to be used with skill.  And the moulding process usually takes some time to perfect.

[Flux]

There is nothing really difficult about carving blades if you have at least some basic ability of wood work. if you have a mental block you may not manage it.

I started below the age of 12 and my woodworking skill then was adequate. I also prefer to use hand tools, I can't stand the mess and noise of power tools but you can do it that way better if you can't sharpen hand tools. Hugh is right in that the job becomes near impossible with blunt tools.

Don't be too worried about absolute perfection either, as long as you are near it will be ok, slight differences between blades will not matter as long as you balance them properly.

Some years ago I rewound a Lucas freelite dynamo for a friend and he wanted instructions on how to build a prop for it. I sent him details which he managed to follow and being a carpenter I thought it would be a brilliant job. He did it and it worked well but when I saw the thing it was as rough as the proverbial bear's bottom so even with a fast 2 blade prop you can get away with a lot. Don't be afraid to have a go

Flux

[DragonFly III]

What if I was to Make a jig for my table saw.  Then I could rip them out.  I can actually do some things on a table saw that I don't think it was meant for.  I made door moulding once for my parents with just a regular blade. (crap bladesince it was the one my table saw came with)  I have a new blade now.  All the friction from the dull blade warped the crap out of it. 

I use to make whirly birds.  Its a hand carved prop about 6 inches long and a dowel attached to it.  When you hold it in your hands like you were rubbing them together and slide them apart you spin the dowel and up it flies. 

I would "carfully" take down the rough angle, actually 3 to get a trapezoid look' and then sand away.

Any thoughts if this can be done with windmill blades?

[Flux]

You can do quite a bit with a table saw, you can rough out the profile easily enough but if you go for the supposed ideal curved shape of the trailing edge you will need to do some hand work as well.

With care you can also deal with the thickness. Except for very big or slow speed blades I doubt that it would be worth trying to cut the angle on the leading edge. There is not a lot to come off here and if the blade wanders off you may have a failure, If you don't want to hand carve you can do it with a power plane or a coarse sanding disc if you can live with the mess.

The back surface is not easy to machine but you can rough with a power plane or again a coarse sander will do the job but you will have far more mess than doing it with a spoke shave or drew knife, it's fairly easy to deal with shavings but sanding dust will be everywhere.

Don't be afraid to have a go, everyone has their own methods, just choose what suits you.

Flux

[luv2weld]

DragonFly III
The dread factor is always the worst.
Don't let your mind trick you into missing this important step.
It is Not Bad at all.
Especially is you enjoy looking at a finished project and saying "That looks Great!! And I did it!!"

Here is a link to how I did a set of 10 foot diameter blades.
But the most important  tidbit in here is oztules idea to use a chainsaw. Oztules is my hero!!!
http://fieldlines.com/board/index.php/topic,129766.0.html

http://fieldlines.com/board/index.php/topic,140377.0.html



And if you just cannot bring yourself to try carving wood
then maybe you should try making a set of Zub Woofers.

http://fieldlines.com/board/index.php/topic,142104.0.html

Once you see how easy it is and how well they work, you will be like 97fishmt, making 4 or 5 sets a month!!!

Ralph

[DragonFly III]

i will be using the table saw for the rough cut.  to remove larger chunks so that there is less carving.

the leading edge could be started by cutting the "corners" of making carving a bit less time consuming.  i also like the idea of working with similar blanks and then i can consentrate on matching them while i carve.

[97fishmt]

Yep, the month isn't over yet and I'm on the 5th set for July 2010.

I am going to pick up another Rohn 45G tower the day after tomorrow.

I'm hooked!   Don't be to concerned on your first set about being
perfect.  The next ones will probably work better.  Follow Hugh's
design or look at what Dan does.  They will work if you make em
from simple straight cuts or complex curves.  Just try to make em
all the same.  And have fun.  I love working with cedar if you can get it.

[DragonFly III]

All though using a draw knife seems to be fun and definitly good for the ego when you see them flying but it's just not something I am capable of.  Picking up my 24 lb daughter sometimes pulls my shoulders out so I don't think hours of carving will be feasable.

I know I'm asking you guys to think out of the box,  I've been doing it for so long I lost my box.  Have no Idea where I put the dang thing. 

I have serious limitations physically but it hasn't stopped me in my 35 yrs of life.  Yes it's been since the womb so 35 1/2.

[SparWeb]

It's too easy to assume that what's easy for me is as easy for you.

I'd say that carving is 1/2 muscle work 1/2 brain work, so if anything puts you at a disadvantage on the first count, there's always the second part that makes up for it.

The chainsaw business is rather hard to manipulate, but maybe you can consider using a router, mounted on guides to keep it from cutting too deep.  It's been tried before, but I don't know if a lot of pictures can be found to help you picture what should be done.  I actually tried it myself, but I wasn't having fun and it was actually taking longer than just going at it by hand.  You need rails on each side of the blade, clamped down so they don't move, with a tilted shape.  The router needs to slide back and forth, following the rails in such a way that the curvature and twist are cut by the router bit.

[birdhouse]

dragonfly-  i think someone mentioned it earlier, but an angle grinder with a 36 grit flap wheel makes shaping REALLY FAST, and there isn't hardly any muscle involved.  just lots of noise and sawdust. 

someone on here at one points also had a great idea for first time blade carvers.  start with four blanks, as your first will probably turn out the worst.  then when you are all done, you can pick from the best three.  or just start with a dozen blanks, then your bound to get three alike.     but really, it's not as hard as you think.  jump in head first and you'll end up with a set of blades!

i also find a contour guage is nice when your getting close.  you can put it on one blade, then transfer it to another and see how different they really are!

http://www.google.com/products/catalog?q=contour+gauge&oe=utf-8&client=firefox-a&cid=12648685798573232827&ei=ur1QTPmIE6KeiQSC9-HNBQ&sa=title&ved=0CAcQ8wIwADgA#p

good luck!  it only took me 6 months to carve my first set (due to busyness). 

adam

[DragonFly III]

Well all of you have twisted my arm...lol
As soon as I get moved into my new house I will try to carve some blades.  I will most likely be posting often when I do to get some step by step progress reports.

Chainsaws and someone like me is like throwing gas in a fire.  I get hurt by hand tools when my hands go a fumblin so I stay with the simpler tools.  The angle grinder Idea seems to be a good route for me along with acouple of other power tools to get me to a basic shape.

I am actually quite ambitious to try new things.  I just have to figure out ways to do them in a way that I can manage.  You guys have definitaly helped me make up my mind about going this route.  Thank you

[DragonFly III]

oh yeah...recomendations for best wood for a beginer

[Fused]

Cedar is some of the easiest wood to work with, but not always easy to find clean wood without knots. I made a set with rough cut cedar 1x4 a couple times. It suffers a bit on root angle and start up may not be as good as a 2x4 would be, but its a easy, effective set of blades that can be made quickly.
I use a belt sander after I get the excess wood removed by cutting slots.

Mark and cut out all blanks, then transfer all lines to wood for cutting angles. Get it close to line then fine sand to your lines.

I attached a few photos of some blades I made for a friend to show how I mark out lines and mostly finished product. Took me like 2 months on and off.

Hope it may help
Fused

[Fused]

http://s298.photobucket.com/albums/mm249/Southbuck7/?action=view&current=MVI_0109.flv
If you feel like it there are other blades Ive made and flown on my photobucket album.
Heres a set of those 1x4 cedar blades on the conversion motor I just re did for 24v system. Was on 12v system in the video.

They did work well, and could crank out a set in a day or two.

Fused

[imsmooth]

I feel it I should point out there is another method for carving blades using a chainsaw.

http://www.youtube.com/watch?v=zIJaKb3teSY

There are other videos of mine on YouTube that you can reference.

This will reduce the time significantly and give you raw blades that are close.

Here is a link to my tutorial on making the blades.  I first used cedar, but found that laminating pine from Home Depot was just as good or better.

http://www.mindchallenger.com/wind/bladecarving.html

[Fused]

4 posts above yours imsmoth he discusses using chain saws.......


Just what I read.

Fused

[DragonFly III]

Imsmooth

That is a great set up and doesn't require me to actually hold the chainssaw in the air.  I'm still afraid of them
How did you build your jig to hold the blade.

I was thinking something similar but vertically so I can run it through a stationary saw (bandsaw/ tablesaw).

[DragonFly III]

Or maybe use a sawsall with a long blade and maybe a rail on the opposit side to keep the blade flat

[imsmooth]

I built a table/sawhorse using a straight piece of wood that is at least as wide as the wides part of your blade.  I believe I then used 2x10s for the rails on each side.  I used lag bolts to hold them in place so I could adjust them. You need to cut the profile on each of them so the chainsaw tracks the proper pitch at each station.  If you look at the pictures on the tutorial you will see metal sleds that are at the front and back of the chainsaw.  This slide on the  tops of the rails.

So, I use clamps to lock the uncut wood to my sawhorse.  I put the chainsaw with freshly sharpened blades at the end and guide it through.  It gets very hard to cut as the pitch increases.

[Fused]

Who ever got my pics to show up, thank you.

The top picture shows a 3 foot dia blade sitting on top of a 4 foot blade. That's the tip width difference.


Fused

[kurt]

your welcome 

next time try reviewing the photo posting faq down in site news before posting photos

http://fieldlines.com/board/index.php/topic,143664.0.html

[fabricator]

I used imsmooths chain saw method, you can make really nice blades that way because you are using the same jig for all the blades they come out almost identical, my blades were 102" long and 14" wide, if you really don't like the idea of carving blades just order some from Royal Fabrication.