10' Furling Tail Weight

[watermanhfl]

Today I lowered mill and weighed the tail as was suggested.  Length was 68" with a 3'6" by 2' tail(fiberglass tub surround) mounted horizontal.  Weight was 14.5 lbs measured at 48" from hinge when laided on floor.  Mill was furling correct about 25 mph mark but always was about 15% off facing wind.

Moved tail further out on tail pipe, squared up tail and removed some of tail support.  Then I ground a bit off hinge bumper(down position) to make tail about 15% vs 10% from perpendicular from blades.

Result, same 14.5 lbs at 48" but now tail is 78" lg with 3' x 2' tail.  Mill tracks much better.  Should furl the same.

[Flux]

That should be a useful starting point for new builders. Any tail that exceeded the 14.5 Lb at 48 inches would probably be furling at too high a speed. I assume that you have a 5" alternator offset.

Flux

[watermanhfl]

Windmill is Otherpower 10' design with 5" offset.  Used square tubing to simplify mount fabrication but angles are the same.  Picture is of early tail which was too heavy and furled late.