Tilt back furl #2

[harrie]

This is view of spindle in normal position.

view of spindle in furl position.

view of parts prior to assembly. It might be hard to make out, but the larger pipe in the back, has two brass berings pressed into it, one at the top, and one at the botom. they have grease zerks, and make a very tight swing bering for the unit. The pivit for the furl, is centered in the shaft over the vertical swing pipe. If I did it again, I believe it would be better to make the pivit at the bottom or the spindle shaft, where the tail and all would move up and down while furling. Dan B. brought this to my attention, and even tho it works fine as it is, I think you would beable to get by with a single adjustable spring instead of two heavy duty ones that I had to install on each side of the hyd. cylinder due to the heavy weight of the genney. If tail and all piveted, the tail would act as a counter balance.

this is finished geney in operation and on the 60 foot tower. You can also see my work platform. Dan B. asked about the tail, It is made of 16 gage sheet metal. the main shaft, is 1-1/8" dia. solid round stock. this is welded to two pieces of 2" x1/4" flat stock that has sheetmetal sandwiched between it with through bolts evey 6 " the length of the tail. I have this same arangement on the single phase that has been flying for almost two years now, and so far has not shown any sign of weakening. with the viberation that you get with the single phase, I would think it gives it a pretty good test.

Thanks all of you for the comments, and I will try and answer any other questions you may have.

Great fun Harrie

[rotornuts]

I gotta say Harrie, that is an extreamly fine piece of machinery you've built.

Congradulations

Mike

[Smithson]

     Where did you get the hydraulic cylinder?

     If you were thinking of building a tilt back design with the blades going up and the tail going down that has been tried.  I read of someone who had the simplest idea to attach the tail directly to the rotor so that when the rotor would go up the tail would come down.  But then the whole unit would just wildly pivot around the tower with the blades up.

     I like your idea just the way it is.     Smithson

[harrie]

Yes, maybe your right, As it is now, I have not saw it turn at all, it just stays directly into the wind, and dose its thing!!. I got the hyd. cylinder from The surplus center. they have a great catalog, www.surpluscenter.com. thanks for the reply. harrie

[TomW]

harrie;

Looks super nice. Congratulations. Is that some kind of vehicle shock absorber or something along the lines of those things that assist in making a rear hatch type door work smooth on some cars or maybe a steering damper shock?

Thanks.

TomW

[harrie]

Tom. I forgot to give the item number of the cylinder I used from the surplus center, It is Item #9-6476. It comes with a slip slot on the rod end, which I removed and added a normal pin hole to the shaft. It was used for lawn mower lift device. Harrie

[georgeodjungle]

how do you tilt it.

manually?

from the ground?

air in the line?

wind switch?

pressure sensor?

[kitno455]

it tilts itself, cause the hinge is lower than the propshaft.

the hydro cylinder is dual ported, with a feedback tube. its just there to slow the motion, making it exactly the same as an automotive shock absorber, without the gas charge. i would use an auto shock instead, something like double eye ryder gas off the rear of any 70's fullsize GM. get one with the cover that moves down over the body, so that the shaft is not as exposed to the elements.

then you dont have to notch your supports to clear the feedback tube, and there is no tube to break. plus, gas shocks have a bit of spring to them.

allan

[hvirtane]

Really nice workmanship.

- Hannu

[georgeodjungle]

can you adjust or fine tune when to start furling and how much?

or is it preset.

the shock absorber sounds like it would work.

as an 4wd rock crawler.we do not use the cover nor do the mud boggers.just the street pounders use them.they tend to keep the water and crud in.

you could cut weep holes.a bit of grease will do.

satellight actuator covers "boots" would work.

plus there's adjustable shocks.

for that fine tune.

some for more in and others more out resistance.

the gas ones tend leak out after a wile.

you could drill, tap add a valve to refill-em.

:

how do you decide when to start tilting?

[harrie]

Im not sure if you can use a shock absorber from a vehicle or not, the reason I used the hyd cylinder was so I can control the amount of fluid that flows between ports. I thought I would have to put a small valve between ports, but as it worked out, It wasnt necessary. The furl adjustment, is in the springs that are mounted on both sides of the cylinder. they and adjustable for tension. Of course there is times where the wind is turbulant, and maybe some up drafts, that will effect the operation of the furl, but most of the time, it seems to furl where I want it.

Thanks for the repley, Harrie

[Devo]

Thanks for the photo's & part # harrie -looks great & nice ingenuity

Devo

[georgeodjungle]

nice.

[scoraigwind]

What amazes me is that it tilts itself at all.  The offset is very small to overcome the weight of the machine.  But if it does tilt, I can see the need for the damping.  It would get lighter and furl right back.  

If you add a spring to the system you can make the furling more stable and you would not need the damper.

Thanks for the pics of a nicely engineered project with nice presentation.

[harrie]

Thanks for the comment Hugh. Yes, As I mentioned, I beleive it would be better to have the hinge lower. I do have a heavy adjustable spring on each side of the Hyd. cylinder. without those, I dont think it would furl at all. I think what is happening is the springs are set to lift most of the weight, and the wind dose the rest, But without the cylinder, im afraid it would slam around too much. I plan on building another one with the changes, so will let you all know how it works out. Great fun, Harrie

[Ungrounded Lightning Rod]

I assume the prop shaft is above the rod pointing out of the hinge.

I notice that this has positive feedback:  As it furls, the center of drag moves farther above the hinge, increasing the furling moment.  It looks like the increase from that is more than the decrease from the tilt-back reducing the amount of wind drag.  So it will go from no-furl to max furl and back with considerable hysteresis - a bi-stable situation - rather than hunting for a middle position.

I also notice that the maximum furling is only about 45 degrees, resulting in only about a 30% reduction in the apparent windspeed experienced by the prop.

[harrie]

No, the hinge is centered on the prop shaft. The wind in our area, is rated at #2, so we do not have alot of high wind as some of you have, but I have not noticed a movement of the full tilt to be what you would call a full fast movement going up or going down. It depends on how strong the gusts are. sometimes it tilts half way, sometimes it goes all the way. but when it dose, because of the hydralic restriction from one port to the other, it just wont allow it to move fast. And Yes, I would say you are right, full furl is about 45 degrees. I think with that degree, and the fact that the RPM of genny may be nearing stall, it seems to do what I need it to do. I guess I dont know what it will do in say 50- 60 mile an hour wind, and dont think I want to know either. I usually shut it down if I think a high wind of such is comming, mainly because when we get wind like that, we also have sever lightening.

Thanks for the comment, Harrie