Where are we at with the 17' turbine...I want to build one

[ve7khz]

Hi Gang,

I'm new to the group but I have been reading it for a few years now. I am finally getting around to building the 17 footer but don't want to start until I get some confirmation of a "final" design. I have seen a few different people's construction techniques demonstrated but haven't seen any updates on DanB's 17' page.

Dan, could you let me know what variations you recommend from your 17' page? ie, rotor size, magnet strength, coil winding data etc? I think Shawns unit was wound for 48volts??? (from last November) but you mentioned some changes to the rotor size and coil windings.

Thanks guys!!!

Paul

[GeeWiz]

Ya, I'll second that.  I'd like to build one too this summer.

[DanB]

Hi - Im not sure there is every anything such as a 'final' design.  Perhaps we should call it the 'latest experiment'.

The blades have not changed.

The origional page is here: http://www.otherpower.com/17page1.html

We changed the rotor diameter to 18"

We are using a heavier duty wheel hub.

We upgraded to N40 grade magnets

The stator is closer to 3/4" thick (instead of 5/8")

The stator is 2" larger in diameter.

Overall, all the pipe is larger and all the steel parts are heavier except the tail boom, which is about the same.

These pages all have some of the detail.

http://www.fieldlines.com/story/2006/11/1/155025/392

http://www.fieldlines.com/story/2006/11/12/161630/06

http://www.fieldlines.com/story/2006/12/10/152829/44

I doubt this one will go up before next spring - we were optimistic about getting things done sooner, and the tower is under way - but the heavy snow has delayed things I expect for quite some time.  I look forward to getting it up and tested though!

A safer machine might be to go to the next thicker gage of wire, reduce the number of turns appropriately, and fit a smaller blade.  It would surely stall if you did but you'd be almost assured that teh stator would never burn out.  I think this one is still on 'risky' ground although the way we have it set up now it should furl earlier than my current 17' machine.   The cutin speed on Shawns is still a bit too slow (partly due to stronger magnets) so my thinking is if we used two strands of 14 gage in hand (rather than 15 gage) and perhaps 50 - 55 windings or so per coil then we could fit a 16' blade and have a bit less heat in the stator.  Resistance might have to be added down stream in that case to prevent if from stalling.

[ve7khz]

Thanks Dan! That's the sort of info I was looking for. The coil data you indicated above is for 48VDC right? Would you still expect it to generate 3KW at the same wind speed with 16' blades?  

Thanks for the great web site and all of your design work on this. We will add some more info as we get going on the project, pictures, performance etc.

How is the 20 footer doing? I was contemplating that one too but I think I will stay with 17'.

Cheers!

Paul