I am currently designing a VAWT with three blades, bucket style. I am almost ready to start the build, then test. Would like to design a VAWT Helix type bade maybe a 3 or 5 blade design and test that out as well. I’m looking at a blade height of about 8 feet, and a diameter of about 4 to 6 feet. Trying to design something useful that can be build at home, but the helix part of the blade design has me scratching my head.
Not quite sure if this is the required geometry, but it may be the basis of a usable solution.
Helices.skp (97.2 KB)
I drew it using
- SU Draw Parametric Shapes plugin (from SketchUcation)
- Fredo6 Joint Push Pull (also from SketchUcation - part of Fredo6 Collection)
I first drew a Helical Ramp, with these parameters:
Then rotated 120° and copied twice to get three blades.
Then used JointPushPull to give the blades depth of 12".
Does that help?
The cross section of the blades is an airfoil so the helical lines would need to be used as a followme path. Then the blade rotate copied.
Thanks, Dan.
Then just drawing a simple helix (another option in the SU Draw Parametric Shapes plugin) , plus FollowMe, or maybe Eneroth’s Upright Extruder would allow propagation of the aerofoil shape.
I’ll try that in a few minutes.
I was just finishing a version using upright extruder to make the airfoil shape. First follow Box’s excellent gif about making a helix which just came up: Drawing a helix. no extensions - #2 by Box
Then make the airfoil cross section flat on the ground and upright extrude it up a helical path.
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Indeed - you got there just before me, and with a different but equivalent solution.
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Lots of ways to skin this cat, It’s all good fun. The advantage of upright extruder is that the blade ends stay at 90˚ relative to the axis.
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Indeed. For speed, since I don’t have Upright Extruder installed at the moment, I just used FollowMe but Upright Extruder is often closer to what you want.
Yeah, it’s a great extension. I’m a big fan.
groan, dad joke.
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