tork blade

[hiker]

thought i might try this torky blade--instead of one big high speed blade..

my alt is geared up so i need tork to get it started..other wise its like

starting out in high gear with your car--you just get no where..

once my alt starts the gears do the rest--it still cranks up..

plus this blade was easy to build --didn"t even  bother with a airfoil

on the back side--well i hope  im not blowing smoke for i still have to sand

it down and screw it and glue it togeather--time will tell !!

[iFred]

Your going to loose a lot of speed and preformance because the pitch is constant. i wonder if you will get anything out of it. Speed is better then torque with generators but thats just my oppinion.

[hiker]

geared up alt.

[tecker]

   Seems to me the gears would tend to keep a constant output . Direct drive has has the advantage of reacting to the wind the reactance would give you some gusting peaks .

 The large units are all gearhead designs .  the wind mills used for milling are geared down also so what you sacrifice in speed may give you constant out over a wide range of wind changes .  

[Dan M]

I like the looks of your hub.  Is it sandwiched plywood or what? and are there fasteners to hold the blades in place or are they just glued?

Thanks,

Dan M

[hiker]

the hub is made out of three 3/4" plywood disks..

the blades will be glued and screwed down.

after test fitting blades .i belive i over did it on the pitch..

may try to feather out the blades somewhat with my belt sander..

it just a test prop--hopefully i"ll get some power from it.

if not it should make a great overhead fan for the shop!!

[hiker]

not sure of where my postings are going..

one more time--the hub is made from three 3/4" plywood disks..

the blades will be glued and screwed down..

this is just a test prop--the pitch is a little steep..

may have to feather out the props with my belt sander..

[hiker]

hub is made up of three 3/4" disks..

blades will be held in place with screws and glue[epoxy]..

its just a test blade..pitch is a little steep..

[TomW]

hiker;

not sure of where my postings are going..

Apparently going right where they should. I did kill one that was an exact duplicate of a previous comment earlier but since they were identical it seemed the thing to do. I left this one because its not an exact duplicate of the previous. I resectioned the story to "Wind" also since that is where it should be anyway.

Cheers.

TomW

[Norm]

You may be losing your postings but we're not ....we're gittin' evry one of 'em!

    Just ribbin' you ...don't take offense

You could almost change the pitch by skrewing the 3 plywood disk around....

             ( :>) Norm

[hiker]

strange i have to hit the refresh button on ie 5.5--to see my latest posting..

doing the same on my other sites--must have some sort of bug ?

well later --try to figuer this darn PC out

[hiker]

sorry guys just running a test here..

[windstuffnow]

  iFred,

     Those blades aren't that much less efficient than the airfoil.  The old aermotor mills were around 30-32% efficient where pro-built airfoils are around 42-45%.  Homebuilt airfoils are usually around 37-42% depending on how well their done.  With that in mind your only gaining 7-12% over a flat angled board with the ends rounded off.  

     The advantage of speed is definately an issue when designing an alternator.  But as far as the blades are concerned if your getting 30 rpm at 50 ft lbs of torque or 300 rpm at 5ft lbs both are still making .28 hp.   The difference of say 100 watts on the flat angle blades to 139 watts on the airfoils ( given a 12% difference ) isn't a major improvement, although, still better.

     I've found just about anything you put in mother natures way, she will move it and there is alot of room for improvement in our conversion methods.

Have Fun

Windstuff Ed