maple blade update

[rotornuts]

Well here's a progress report. I've decided to go with a wire frame for the trailing edge of the blade. I'm trying to retain the maple look as much as I can, Why? I'm not sure. I'm thinking I'll cover the whole thing with fiberglass and vary thickness to assist balance. As it is the counterbalance is a few ounces light. One picture is just a front view but the other shows the transition area where I'm hoping the center of balance or axis will end up, actually I'll have to make it end up there. I'll actually set up the hub as one of the last things I do so I can locate it correctly rather than have to make everything else work for it.

I'm open to suggestions for covering the wireframe and also hub construction. one idea on my mind for the hub is to use the ball from a ball valve so I can tilt the rotor on two axis to help with balancing.

There's still alot to be done and I'm taking it slow, the tools were getting dull(myself included) so I stopped and decided to update.

Btw this is the origional maple blade getting reworked and many compromises are being made.

"nuts"

[johnlm]

Hey Nuts,

Damn thats a nice looking seed skeleton.  If it doesnt work you can hang it on the wall in your living room as a piece of art.  

John

[christopher]

Nice looking blade, rotonut.  If the trailing edge is ridged enough this looks like a prime candidate for one of your wife's silk scarfs and some airplane dope. Good luck.

Christopher

[troy]

If this is even "reasonably" successful from a technical standpoint, you would have a very marketable windmill.  The ad copy people would have a heyday.  "Nature has been perfecting the performance and aerodynamic design of the single bladed windmill for thousands of years.  Now our designers have used finite analysis, wind tunnel testing and other advanced techniques to replicate the high efficiencies of the maple seed.  This unorthadox yet natural design ushers in an entire new era in practical, beautiful and efficient windpower using the intelligence of nature."  Cool photos, cool graphs, etc etc etc.

Did I mention I want a 1% royalty?  Hee hee hee.

Thanks for the beautiful work,

troy

[electrondady1]

this is so interesting roto. may i suggest acrilic plastic(lexan, plexiglas). to fill the void. its very strong , like bullet proof, it can be laminated, and can be machined nicely. a good source for used acrilic is a sign painters shop.

[windstuffnow]

  Check out some aircraft covering sites such as Wicks aircraft or spruce and specialty.  Alot of experimental builders use a "stits" process which is basically gluing down some polyester cloth and heat shrinking it.  Then painting it any color you want.  An older method was to use cotton cloth ( like sheets ) although cotton only had a 5% shrink where poly cloth has around 10-20%.  Let me know the area you need to cover and I'll see if I have enough on my end roll to donate to the cause.

  Once you get it glued on you simply set your iron to around 175 degrees and start ironing, it will get as tight as a drum.  A hobby iron works great for fine tuning corners and getting any small wrinkles out.  It's actually kind of fun to work with.  I covered a couple airplains using the stuff and it comes out quite nice.  After its coated ( painted ) it has a 7-15 year life span.

Nice work!

Have Fun

Windstuff Ed

[Norm]

  Great goin' Rotonuts! It's beautiful! How big is it from tip to tip? Think I'll print it out and hang it on my wall!

                    Great Fun!

                   ( :>) Norm.

[monte350c]

Hi rotornuts -

Ed's suggestion is bang on. That will probably be the lightest method to cover your creation. And the closest you could get to Mother Nature's method on the original.

Here's a how-to on the basic process I came across a while ago:

http://www.airtechcoatings.com/fabricdummies.html

Probably better/easier/neater than the fiberglass too.

Ted.

[rotornuts]

Hey guys,

I think I'm with ed and ted on the aircraft covering and about 2.5 sqft should do it with a little extra. The lift portion of the main blade is about 1 sqft(basicly to the hub). This one is sizing up to be 40" total length with about 29" on the main blade side and 11" on the counterbalance. The lightweight aircraft skin will let me fiberglass the hub and counterbalance and hopefully correct the light counterbalance problem without adding "point" weight which I'm afraid will then require corrective weight and so on till I fire the whole thing in the can. Thanks ed for the wireframe idea I came to realize it's the only way to achieve the correct proportions.

Keeping this thing as light as I can has been my objective this time around as I'm sure additional mass only serves to amplify any out of balance situation.

I'd still like suggestions on the hub. As I said before I'll locate the exact position of the hub after the blade is basicly done but I'd like to give it a ball joint so I can tilt it forward or back and twist or pitch it side to side, I'm hoping this way I can coorect the balance on two axis without weight leaving only the conterbalance/blade to be corrected with weight. I've been thinking of creating a socket open towards the front, taking the ball from a 1 1/4 ball valve welding a 3 or 4" shaft through the center then have the shaft turned down enough to thread only 1 1/2" closest to the ball. Bore a 1/2" hole in the center and drill and tap for a set screw for mounting on the induction conversion. Drop the shaft with a ball on one end into the socket thread a nut on the other side and when it's in position tighten it up then mount to alternator. Only problem is that it requires a mating cuved surface on the back side or it will straighten out when you tighten it up and that's a pain. Remember I'm unlikely to have any flat surface to work with so containing the device to a very small area is a must and having the blade itself as an integral portion of the assembly is also important as there will be little to fasten anything to.

Can anyone see an easier way. Other than not attemping this.

P.S. It would be poosible to use short straps running lengthwise but I'd like to avoid if possible and thanks for the comments.

nuts,

[RP]

I think you need a constant velocity joint from a car.  Take a look at this:

http://www.scargoracing.com/html/stuff.htm

Look at the bottom left image in the link.  These are used to transmit the torque to a driven wheel on a car.  You could extend the shaft through the joint, add a "tripod" affair where your nose cone would go (from the end of the shaft back to the blade).   Make the legs of tripod threaded and adjustable somehow.  Then you could dial it into any orientation you'd like.  Also, this makes a nice bolt on hub to transfer the torque.

rp

[windstuffnow]

  Rotornuts,

     I believe the roll is 60" x ?   How many feet will you need?  Keep in mind you want to go around the wing so count 2 sides...   Let me know and I'll check out the stash... shoot me an email with your address...  I'll check the glue supply but if I do have any it probably isn't much good so you may want to order a small can...

Windstuff Ed