But it is not for the average builder. Way too complicated. Jlt
It wasn't meant for the average builder. It was done as a proof of concept to show that a very powerful high performance turbine can be built using ferrite magnets in an air core axial design. Nor was it meant to make most efficient use of materials. It was designed to show the more advanced turbine builder what you can do with an air core axial using readily available components, without having anything custom built.
If you get too hung up on other concepts like using a toroid core, aka Gordon Proven, or maybe using a radial core, aka AWP - you lose sight of what you're trying to accomplish and leave the realm of even advanced home builders. Sure you can get better magnetic performance from other designs. But when the magnets are cheaper than dirt, why bother? This turbine was built using commonly available parts, sheet and tube steel, ferrite blocks that are commonly built and stocked. And being an air core does not require winding a toroid core or finding or building specialized motor cores and/or laminations. It was designed from the ground up to use a proven controller that can be purchased from a reliable company that has years of experience building RE equipment.
Hugh, oz, et al didn't see the Big Picture. They tended to get too hung up on specifics like "I can get better magnetic performance by doing "x". That wasn't the goal. It is an integrated design to get extreme performance from an air core axial on battery charging, making compromises here and there in the design to achieve the desired end result. It was not an exercise in making best use of magnetic volume.
And this is where experienced and skilled engineers often depart from "accepted norms" in a design.
Later, I built another identical machine with a neo generator in it to compare the performance of the two turbines. I found I can get no more power from the neo, even though it operates at much higher voltage than the ferrite unit. The ferrite machine has an internal resistance of .55 ohm, while the neo is .47 ohm and operates at almost double the voltage. Theoretically, it should be much more powerful. But it's not. Why? Because the original ferrite design already pushes the blades to the edge of their performance envelope and there was nothing to be gained by building the generator more efficient (and more expensive).
The other thing that I hate about the contemporary homebrew designs is furling. They have to furl properly or they'll burn up. I wanted to build a turbine with a generator so powerful that it can develop 15-18 kW of braking power for a 10 foot machine without hurting it, and not need furling for power control. The only thing I use the furling for on these machines is to let the turbine turn to the side of the tower in strong storms where the wind gets over 40 mph, to take some of the load off the tower.
I don't build and post these projects for the newbie, or for the "average" builder that thinks it's too complex or hard. I post them for the experienced turbine builder who realizes the gross performance limitations of the contemporary homebrew book designs and wants something better. They can look at it and go, "Hey - I could do that". This gives the "old dogs" fits because I show folks everything from how you can use "wrong" magnet spacing, to "wrong" coil shapes, to maybe even using dual stators to achieve a desired end result that still uses most of the time proven construction methods outlined in the homebrew books.
When you take something like Hugh's basic air core axial design and re-design it to push it to the raw edge of maximum performance you have to think outside the box and never let "conventional wisdom" get in the way of what you want for an end result. Not to mention that it's incredibly satisfying and fun to see a turbine that you crafted yourself running at such high performance levels that you can't squeeze even one more watt out of the potential of the blades driving it. My geared turbines flat out STOMP a Bergey XL.1 Noise Maker for performance at a fraction of the cost in materials to build one. And that puts a big grin on my face every time I see the ammeter laying on 90 amps combined with the hum of some serious high performance equipment on the tower. You gotta' have fun or you've lost sight of what it's all about
--
Chris
