Smartdrive F&P Decogging or not?

[domwild]

Hi,

Sorry to bother you with decogging questions! Am worried about loss of power and having to buy a power file for the decogging as recommended by ecoinn in New Zealand. Suggestion is not to use a file as one will damage the windings. A recent article in "ReNew", an Australian green magazine, mentioned that to ecoinn's knowledge, no one has successfully built a mill without decogging. Decogging gets around 50%  to 63% of the initial cog.

Ecoinn has even built a hub that allows an idle spin of 90 degrees before engagement of the alternator takes place to get around the residual cog. If so, I would be very interested to see a sketch or explanation how that is done if someone has built one.

If a mill has been built (decogged or not) I would like to hear which prop then drives it. Is it a Jerry, Hornet, total Alu profile by the meter or the Piggott Peru or Indian profile made out of wood?? And how many blades were used and did it need a furling system as carbon fibre blades seem to take up to 1500 RPM. I am using three bearings on the shaft, two pillow block bearings (25mm inner) which are better than the original 6005 SKF bearings and one 6005 for the rotor. Vibration should not be a problem??

Dominic

[gizmo]

I've built a few using the F&P motor. Decogging does make them start a little easier, but most of my windmills have not been decogged at all. I figure if there is not enough wind to start the windmill, then there is not enough wind to make any serious power anyway, so might as well save the bearings and leave the thing idle until the wind picks up.

My blade diameter is 2.2 meters, and a standard non-decogged F&P will start up in about 20kmh winds. The decogged F&P's start at 15kmh.

There is more info on my web site.  http://www.thebackshed.com/windmill

Glenn

[commanda]

The man to ask would be Glen Littleford at DIY windmills.

http://thebackshed.com/windmill/

Amanda

[gizmo]

Thanks for the ref

Glenn

[domwild]

Thanks, group. What sort of blades, how many and any furling, if I may ask?

Dominic

[BruceDownunder]

I "think" a way to overcome the cogging is the twin set up , But Glenn is correct , if there is not 15-20 kph wind ,then just wait .

I set up two stators on the same shaft by cutting a spacer ring to distance the two stators apart then use longer bolts to clamp it together --Oh,by the way ,you can turn one of the stators slightly before tightening the bolts ,this helps reduce the magnetic "hold" when you finally put the twin rotor on.

Bruce

[commanda]

If you run 2 stators "out of phase" as it were, to reduce the cogging, you then need seperate rectifiers for each rotor.

Just thought I should point that out.

Amanda