Wind powered sawmill

[fryedbk]

I would like some specs for a buzz sawmill. I am attempting to build one that is wind powered to process some hardwood trees cut down in my area. Any help would be greatly appreciated.

[Tom]

Wind isn't a very dependable or powerful power source.  You might also look into reciprocating, vertical  saws such as were used many years ago with water power.  Wish I could give you specs, but this is over my head. 

[fryedbk]

I live in Kansas where the wind is very dependable and usually powerful, although harnessing it is the challenge.

[Ron Wenrich]

That's an entertaining idea.  Are you planning on using the windmill to produce electricity or use it for some sort of direct power?  The major drawback is you can only saw when there's wind, unless you are using something to store electricity.  

I guess you could scale back to a smaller unit than the "buzz saw".  The smaller band units and even the swing mills take a lot less power than the larger mills.  But these you couldn't use a direct power.

The reciprocating saws you could use direct power, if you have it geared right.  As wind speeds change, your rate of sawing will change.  That's bad on a circle saw, but not so bad on reciprocating saws.  

[fryedbk]

Determining which type to use is why I posted in the first place. I want to use a type of verticle axis turbine with a direct feed to a saw. Maintaining speed will be the biggest challenge, however I can count on a speed of 12MPH.

[logwalker]

I doubt that a direct connected saw would be practical. But I would really like to be proved wrong. What are your ideas to begin with?

[DanG]

An interesting and entertaining idea, for sure!  I don't see why you couldn't run a small band like the portables use, set up like a headsaw.  You should be able to run that direct, via some gearboxes and belts for gearing.  There are some little bandmills running on as little as 5hp.

I've thought in the past that something like those old Dutch windmills would be cool.  As big as they are, they oughta produce plenty of power for a small sawmill.

Welcome to the forum, fryedbk!  We like thinking outside the box.

[KGNC]

My vote would be for a generator/motor setup with battery storage and inverter.
That way you could save up several hours of wind power before you start sawing.
From what I understand about vertical axis turbines that would seem to be a poor choice for a direct drive. They have little power at low speeds and not a lot of torque, some even require an outside force to get them started.  For most sawing applications you would want more rotating mass to help maintain the speed during sawing. Getting all that mass up to speed would be problematic for a low torque power source. But not to be too discouraging, it could be done.

[fryedbk]

I've never been able to find the specs on the different styles of windmills but I don't understand how a "squirrel cage" rotor could produce less power than a rotor using blades. But the old dutch type windmill is also very intriguing as the size would be such that direct and/or electric could be harvested. They were used very extensively over most of Europe, until the advent of electricity, for many applications.

[fryedbk]

And thanks for the welcome and the quick responses already received.

[fryedbk]

For direct a large fly-weight for steadier speed would be needed. Anyone know where I can get pics of the inside of a functioning or restored dutch windmill?

[KGNC]

Just to clarify this is the type of turbine that I was thinking about. Not sure if it was what you meant.
http://en.wikipedia.org/wiki/Darrieus_wind_turbine

[fryedbk]

A Darieus is too complicated. i was thinking more of a squirrel cage.

[KGNC]

http://en.wikipedia.org/wiki/Savonius_wind_turbine

[fryedbk]

Do you suppose by blocking the backside of the Savonius drag could be reduced thereby increasing efficiency? It could be directionalized by the addition of a fin.

[KGNC]

Do you suppose by blocking the backside of the Savonius drag could be reduced thereby increasing efficiency? It could be directionalized by the addition of a fin.

Maybe, but then you lose the main advantage of of a vertical mill, that it is non directional. You would have to find a way to move your shield into the wind as the wind changed direction.

[fryedbk]

Adding a fin to the top of the shield?

[fryedbk]

Having it drive a 24 volt generator from a semi with an inverter and batteries could  power a sawmill. Semi generators will produce 200 amps at 24 volts DC. Not sure what that relates to in 120 volt AC.

[Fla._Deadheader]

It takes 7MPH wind to start an efficient wind generator. NO power to speak of. 12 MPH steady wind, you MIGHT get 600 watts of electrical power. It all depends on the size and square foot area of the Turbine (blades, rotor).
Since 746 watts = 1HP. You start to get an idea of what you are up against. Usually, the squirrel cage type rotor is LARGE and an auto type alternator hooked to it is tiny in comparison.

  A 15 foot Dia. 3 blade turbine can produce 4000 watts at 25 MPH wind. Divide 4000 X 746, and you get 5.36 HP. That does NOT take into consideration the belting, gearing, and other losses associated with getting usable power from a wind generator.

  Might try www.fieldlines.com. They have a good site for Alt. Energy of all types.

[pineywoods]

For a do-it yourself project, the only practical way to get any usable power from the wind (even Kansas wind) the dutch windmill would probably be the only practical way to go. Even then, they aren't as simple as they look. Keep in mind that those windmills are the result of generations of trial and error development. Granted a properly designed 3 blade turbine of the same size would produce considerably more power, but construction would be beyond the capabilities of most backyard tinkerers.

Your 200 amp generator will produce about 7 hp at 5000 rpm....and suck up 15 to 20 hp from whatever's turning it.

[Ianab]

This is an old school sash sawmill from the 1800s that we saw in a museum on one of our road trips.



The saw blade (in the centre of the log) runs up and down like a sash window while the log slowly feeds through the frame on a carriage. I guess it was the logical way of mechanising the old 2 man pit saws. Must have made milling a LOT easier.  ;D

This design has been around since about the 1600s, but isn't used now because newer saw designs cut faster. But it's tried and true technology that was used for hundreds of years.

I believe this one was powered by a steam engine around 3hp, but water wheels are also used. Either way they dont need a huge amount of power, and aren't speed critical like more modern saws.

Its pretty low tech, but that means it's somethng that you could build yourself easy enough.

Anyway, if you did build one it wouldn't really matter what you powered it from. You could connect it to a tractor PTO, a little gas engine, an old Hit N miss, electric motor, a water wheel, or even a windmill

Ian

[Don_Papenburg]

The sash mill would work the best of all .  the feed rate could be geared to the sash so that no matter how fast the sash went upand down the forward advance would be the same per stroke.

[Don_Papenburg]

Also check out this axial wind generator
fadam91@yahoo.com      Adam Fuller in Wisc. developed this windmill.
Look here  :    www.myspace.com/adamman1

[beenthere]

I would like some specs for a buzz sawmill. I am attempting to build one that is wind powered to process some hardwood trees cut down in my area. Any help would be greatly appreciated.

Question was for a buzz sawmill. Are you thinking buzz saw to buck up cordwood, or sawmill type for making boards?

I was thinking buzz saw.  : :

Lots of interesting ideas coming out in this discussion.

[pineywoods]

A sash mill coupled to a dutch windmill would make a very do-able and interesting project. Low speed, high torque power source, Minium parts, just a crank on the axle of the windmill, an old crosscut saw for the blade.  So many neat ideas, not enough time  :.