Dual prop multi gen idea

[GeeMac]

Here is a rendering of what is on my mind for my next improvment/project.

Note that the nacel may be as long as you wish by buiding it in small sections and then joining the sections with connectors. Instead of gluing each section I might run a couple of connecting straps along the length. Doing that will allow for access in the future. The props will be offest so that the blades don't interfere with each other too much. Some purists might complain, but I don't care. The tail pipe will have a zigzag (not shown) in it to move the tail slightly off to one side to cause furling in higher winds.  Because the nacel is built in sections, it will be easy to work inside the shorter pipe section to get the coils placed as they should be.  I'll post pictures as the project progresses.

[DanB]

'Here is a rendering of what is on my mind for my next improvment/project.

Note that the nacel may be as long as you wish by buiding it in small sections and then joining the sections with connectors. Instead of gluing each section I might run a couple of connecting straps along the length. Doing that will allow for access in the future.'

You're drawing suggests that you're winding coils around the pipe... that won't work.  Its much better use of materials to build an alternator large in diameter, rather than lots of little small ones on the same shaft.

' The props will be offest so that the blades don't interfere with each other too much.'

I think they'll interfere with each other quite a bit anyhow.

' Some purists might complain, but I don't care.'

I don't know if I could be considered a 'purist' (and I'm not going to complain).  I would say however ... it's nice to know 'what in the box and why before you try thinking too far outside it'

' The tail pipe will have a zigzag (not shown) in it to move the tail slightly off to one side to cause furling in higher winds.'

That won't make it furl... (unless I misunderstand you)

'  Because the nacel is built in sections, it will be easy to work inside the shorter pipe section to get the coils placed as they should be.  I'll post pictures as the project progresses.'

Best of luck - I look forward to the pictures/progress!

[rippersoftware]

Be careful what you design and display online.  Something very similar to this is supposedly patented by Doug Selsam.  Dual props and a PMA.

see www.selsam.com

A very vocal man about his right to be the inventor......

Now, having said that, tilt the PVC tube assembly about 15 to 20 degrees down in front (maybe more) and the wind will turn both blades without much interference.  No offset needed.  May need to change the pitch of the props.

If you make coils and then apply them to the outside of the PVC tube so that the coils are parallel with the magnets, that will generate.  Maybe not much, but worth a shot.

Actually, furling for something like this would be exactly as you have it shown.  The wind across the front blades may make it turn, but the scrubbed air to the rear would make the rear blade slow and thus slow the whole mechanism or at least limit the speed.

Anyway, look at the selsam site and change 25% to something unique.  Now it's yours.  Amazing how windmills are patented and yet we build them.

RipperSoftware

[GeeMac]

As usual, I should have explained more. I am winding coils around a small piece of iron and gluing, in a row around the inside of the pipe. The magnets will be attached to the inner pipe and will revolve by the individual coils creating a pulse of power. What I didn't mention is that the coil ends will be gathered into a group and fed to a wiring channel in a much smaller pvc pipe on the outside of the nacel.

The main thing is for me to experiment, learn and have fun doing it. I'm stuck in this danged house as a caregiver to my wife and if I don't have something to do, I'll go nuts. So, I make violins and windmills to stay sane. Like everything else I do, ninety nine percent of the fun is in the building and one percent is the satisfaction of completion, but being occupied is what I need.

[GeeMac]

That you for the heads up. I'll take a look at www.selsam.com and see what they have. I'm just noodling around with this stuff, so there shouldn't be a problem. If I was building them to sell to other's I'm sure he would have a case. Nevertheless I'll take a look.

[vawtman]

Would it be possible to noodle around without posting every noodle.Sorry but this  idea has been posted a few times.

I agree with Dan.

[GeeMac]

Okay - I haven't been a member for long and just thought someone might have an interest too.  Please delete it.

[vawtman]

Heres one to read.Gmac if you get a thought google it i learned that over time.

http://www.fieldlines.com/story/2004/4/5/184919/7784

[TomW]

GEE;

Sell Sam is full of:

Usually I just kill any mention of the ripoff artist, this slipped thru. The guy is a world class LIAR and was run off from here for those lies that he could not substantiate.

No Cheer WRT that particular snake oil salesman. That type gives the whole R.E. field a bad name.

TomW

[Bruce S]

But Tom ? he has such pretty pictures!! they just have to work :-)

Just kidding. I do like your graphical designs tho.

I wouldn't buy TP from the guy.

Doesn't answer dirct emails from me either.

Cheers

Bruce S

 

[vawtman]

Tom

 Your bull needs a hole.Usually the hole is just beneath the tail from my experience anyway.

 Looks like hes ready to pop not poop.

 Happy Thanksgiving to you and the family.

[vawtman]

Took awhile to sink in butt got it

[DanB]

I don't think a 'patent' prevents anybody from building anything... it might prevent you from manufacturing/selling something without permission.  I think the basic 'two or more props on one shaft' bit is a pretty old idea and I doubt it'd be hard to dispute the patent if it came down to that anyhow.  To quote Paul Gipe (is this a copyright infringement?) 'theres nothing new under the sun... or the wind'.

[TAH]

Your bull doesn't seem to be a bull anymore. Maybe you need a pre operation image.

[feral air]

A short quote with attribution ought to fall under fair use. Who knows anymore.

Before too long it'll be impossible to have a kid without owing someone...

Someone just needs to patent "contraction of a membrane causing air to be taken into a sack." That sounds like a halfway-legit modification to bellows, just add a rough sketch of a lung-like apparatus and cut the check.

Then all off-spring are "patent infringing devices" and every parent is a "distributor". yay! take it easy

[feral air]

That's a nice idea but sometimes it's better to bring it up again. Go ask a question in some random thread that's a year old and note how long it takes to get an answer.

Then, especially if you're new, you may not always know the proper terms or "sequences" to search for. Do you search for "dual prop", "duel prop", "multi prop", "multiple props", "2 propellers", "two props"....how far do you take it and what of spleling rerors?

When you think about it it's pretty easy to sit there searching for hours and never find anything relevant. Add the fact that old threads are (basically) dead threads and you may as well post a new one in your Diary with an obvious title so that the old-hands can chime in and tell you where it was posted before.

Yup. take it easy

[jimjjnn]

Under US patent law you can build anything you want to for personal use  as long as you don't sell it commercially or earn anything from it

[blimpyway]

I always thought Selsam's turbines have one important problem: fatigue on the long, horizontal shaft.

His shaft needs to:

• support its own weight and propellers
  
• support lateral wind thrust
  
• is quite long and thin
  
• spin at the same time
  
  

A long shaft passing through a single bearing into its middle has a strong tendency to buckle when it spins - a small bend off its spin axis and the centrifugal forces become very high. Specially when two extra weights (propellers) are added at its ends.

That means it needs to be both very rigid and fatigue resistant - and requires fancy composites to last - no wonder Doug uses so often the holy carbon fiber resin. I doubt the shaft will last with anything less like fiberglass or steel tube.

----

That's why any design that uses two shafts: a fixed one for support and rigidity, and a thin spinning one to transmit the power (I consider) is an improvement. It lightens the load on the bearings, can use smaller bearings (spinning shaft is much thinner), and needs no fancy materials.

The limitation of this configuration is it can be used with only two propellers on the shaft.

cezar

[tecker]

 DEE Boull is just talking to the Plumber .

[tecker]

Or maybe Dee Booll on Dee bowell is talkin to to the plumber and reaching for the plumber's friend.

[finnsawyer]

Well, nature will not necessarily behave the way you think it will.  The windward turbine will cause some of the air to spill around it and miss the second turbine or worse, cause added turbulence in the "reduced" flow across the second one.  Because air is transparent, people seem to think that putting something of radius "a" only affects the airflow out to radius "a".  This is not true.  Air is a continuous medium and a pressure distribution in the air cannot drop abruptly by a large amount, but must change smoothly over some distance to the new value.  Basically, putting something into the airstream causes a pressure build up in front of and to the side of the object that must smoothly drop back to the pressure value of the incident air flow far from the object.  I've caused a lot of controversy on this site with my ideas.  If you have the time, as you say, you can check my comments over the past two years or so, as well as my diary.  If you wish to experiment, to whither do you go?  I imagine these last statements will elicit the usual disparaging comments.  To those people I suggest they read the article on the last page of the January issue of the "Sky and Telescope" magazine.  And then let them explore their own motivations.