Indestructable Darrius

[vawtman]

This will mainly test my thoughts of solidity vs rotor speed.

It will be 4x4.

The 8x8 is waiting for the tower yet so i stole some parts from it.

 Blades and their support next up.

[DamonHD]

Hmm, and I thought, "Well, if that's all it takes, even I could make one!"

Then you tell me it needs blades and stuff.  Bv<

Rgds

Damon

[vawtman]

Damon the blades are the easy part.

The support structure around them is more important.

If things were that easy it wouldnt be fun then.

[DamonHD]

Well, I'm definitely working up to trying a very small plastic bottle drag type VAWT, simply because then I imagine I just point the PM alt upwards and slap the rotor on top, which minimises the engineering that I feel incapable of, eg furling, pointing, etc...

Rgds

Damon

[feral air]

How big is the pulley and what's it gonna drive? Did you use square tubing instead of round for a reason?

Looks good.

[vawtman]

Hi Feral air

 The pulley is 24in its a flywheel from a exercise bike.It probably wont be used in the final design other than springscale measurements.Im a fan of flywheels though.

 I guess it could drive a dc motor if one wanted.

 My goal is to build a radial flux for this for practice and see how it reacts before attempting the 32in.

 I dont think there would be much benefit between square and round other than square is stronger.

 There wont be any wind inside it when its up to speed.Just from my trials.The windspeed it reaches this is what im testing.

 Thanks.

[feral air]

24in, cool, cool. I was thinking I'd use a 10-speed wheel as a make-shift pulley for my drag vawt. I have 20" wheels on-hand though so I'll try that first.

On square vs. round, it seems that there's conflicting theories. Even though there's no wind in the center the supports will still need to push air out of the way as they travel around - relative wind, I think they call it. I'm no aerospace engineer but I'd imagine round tubing would be more efficient (less drag). Strength shouldn't be much of a factor at this size.

You use what's handy though, I get that. Square tubing is easier to work with anyway.