2031 The Great Wind Turbine Improvement Mystery

[@JakMang]

This works with sailboat sails that overlap. It called the slot effect. When adjusted properly, the first sail can push more wind onto the second sail and gain a lot of power. Some boats have three overlapping sails. The distance between and the angle is critical for better performance

[@MrZriael]

I assume tuning the distance and angle properly is highly dependent upon wind speed?

[@colrodrick8784]

@@MrZriaeli don’t think so. The usual wind speeds where a regular Bermuda rigged sailboat / yacht is used are anything under say 30knots (60km/hr approximately). The slot effect is apparent at all times until the wind gets up there. Beyond 20 knots most sailors are interested in survival or comfort not additional speed

[@MrZriael]

@@colrodrick8784 That’s promising, would make it a lot easier to optimise…

[@LG-ct8tw]

@@MrZriael It's more a function of aparent wind angle or in aerospace speak, angle of attack.

[@JakMang]

@@MrZriael you are correct. It is kind of an art to learn each boat.

[@stewartj00701]

I've done quite a bit of sailing in my time, and this seems something like the effect you get when you get the optimum slot between the mainsail an the jib, once the slot is too tight it kills the speed, the centre of balance of the rig needs moving forward to give a wider slot, too wide and you lose the effect, one wing turbo charges the second, the jib it rams air around the back of the mainsail at the right angle increasing the efficiency beyond the sum of both sails, they act as one. The big issue with wind turbines is controlling the power, we need improvements in micro wind, mechanical blade feathering systems.

[@TerrorTubbie666]

So, actually, what you're saying is: The front rotor could be much smaller than the back rotor. This will not only save material, but also increase efficiency???

[@TerrorTubbie666]

Do you know of anybody ever experimenting with 3 stages? Like a jib, mainsail and even bigger sail? Or a mini-jib in front of the jib? Would that work?

[@stewartj00701]

@@TerrorTubbie666 quite possibly, there could be room for allot of optimization with this with pitch, blade shape, size and position, it does look like it could be some sort of slot effect

[@OldManSparkplug]

I think you've got the idea exactly, and I completely agree that once we get really high rotations speeds feathering is going to be extremely necessary.

[@TerrorTubbie666]

But this feathering system already exists in some aeroplane-rotors. A system with springs and centrifugal weights makes the blades turn depending on the rotorspeed. When idling, the rotor turns (relatively) slow, so the blades are flat, generating no thrust. When giving it more throttle, the rotor speeds up, so the blades turn, generating thrust. This system pretty much guarantees you will never blow up the engine by making too many rpm, cause the blades will slow it down by going to an insane angle. And it can act more or less as a break, because going back to idle at high airspeed, will set the blades flat, slowing down the plane. But I guess the problem is: This aeroplane-system is a linear system, the faster the rotor turns, the steeper the blades. While in a windturbine, we are persuing an optimal rotationspeed. We don't want it to turn too fast or too slow. Uuuhhm... Damn, I don't know how to explain exactly (in English). Maybe someone else can finish this story??? Added: Other problem: We have no throttle lever to control the system. We are dependent on the windspeed. So, uuuhhm...

[@AdrianCubas1980]

Super happy that you have found so much utility and have done so many experiments with the WINDTURER P4 blades and central hub. If you need larger blades I can design them and send you the files. I am currently working on a slightly larger version of the Windturer.

[@prodiver7]

Huge amounts of work were done more than 100 years ago on the efficiency of fans blowers and turbines. Somewhere I have books on this. To extract the maximum energy from a wind flow axial blades need to have maximum area furthest away from the hub: power= torque x rpm. Check out the old US ranch windpumps with many blades widest at the tips and the big axial primary compressor fans of jet engines.

[@geoffkeller5337]

Would really like to know the titles of those books

[@prodiver7]

Google axial and radial flow fan books. Fans and wind turbines share a lot of characteristics.@@geoffkeller5337

[@ThinkingandTinkering]

huge amounts of work continues to be done mate

[@philip5940]

All those reference and engineering books are immediately thrown out from deceased estates mainly because they don't look pretty.

[@ABaumstumpf]

@@ThinkingandTinkering Sure - but many of the work from back then is definitive. For example we do know that american-farm-style windmills are scratching at the efficiency-limit for their size and purpose, and we know that 3bladed turbines have the best overall performance when considering changing windspeeds. More blades increase the poweroutput at lower windspeeds but their efficiency drastically decreases with speed.

[@ibme8359]

Amazing!!!, Perhaps a third blade set could be added to "The stack" and increase the performance more (probably need to change the spacing and the angle offset proportionately for the new stack). I for one am going to tinker with a 3 stack version! Thanks for the inspiration!!!

[@JaceFuse]

There's a product called XTC-3D, which is a self smoothing epoxy coating for 3D printed objects. I think you might find it useful for things like this.

[@ThinkingandTinkering]

nice tip mate - thanks for sharing

[@colrodrick8784]

I use a lot of epoxy in my boat projects. Their major disadvantage is UV exposure. Unless you coat the coating they will break down (eventually). Since the wind turbine is going to be used outdoors that product may not be ideal for the purpose required. I was also thinking epoxy during the video, then I thought, but wait - UV. As you can imagine UV is a huge issue in Oz.

[@donmcnish3918]

Would love to see performance on a graph wind speed/torque produced. For 3/6 winged blades. I find your videos thought provoking. Keep them up. Kind regards Don

[@andrewsmithmilan1780]

​@@colrodrick8784could you maybe spray a light coat of light colored spray paint to cover the epoxy and protect it from UV?

[@gerryjamesedwards1227]

@@andrewsmithmilan1780 some of the paints intended for marine use protect from UV damage. They are expensive if you're painting boats with them, but even a half-liter would coat a lot of turbine blades.

[@rayadagio]

Yet another new and exciting idea! Another potential way to increase the efficiency of a wind turbine would be to attach winglets to the blade tips to reduce vortexes at the tips, similar to those on the wings of many large airplanes. The improvement might not be spectacular (around 1%), but the best part is that it's cost-free :-)

[@jitone1]

Is that why the helix fans were so quiet?

[@piotrjasielski]

I'd love to see an analysis on how this actually works with higher effciency.

[@huarwe8797]

Would be nice with some smoke and a slow motion camara to see the vortexes.

[@mark.guitar]

Great shout!

[@originsdecoded3508]

I think having grooves and ridges in the proper design of direction and arrangements would provide more optimal air drag surface tension, providing the wind more grip to push the blades with higher speed. Great job in this video in explaining everything so simple.

[@plan9channel7]

KZbin chanel 'Gavin Freedom lover' has been using this design for quite awhile now. Albeit the first blades are smaller in length than the second set. Very impressive efficiency from your demo.

[@mikedmann7487]

My fav time lord never disappoints! TY RMS for all your great videos.

[@ThinkingandTinkering]

lol - cheers mate

[@Frejjan]

Very interesting. I really hope you prints a test mount that has all six blades in the same plane and compare that. And/or start testing for the optimal distance between the two sets of blades.

[@hd-be7di]

A larger version with variable pitch mechanism might be interesting with this design. With a simple board like arduino or rpi it can get wind speed values fed to the pitch mechanism to drastically improve low wind performance without needing to double the blades. Thanks for the STL link!

[@colinkeizer7353]

Fascinating how so many people are thinking about sails and adding one or two turbine blade sets to an 'outside' wind turbine exposed to the elements. My first thought when I saw Robert's demo was to visualize a stack of turbines and stators, just like inside a jet engine or steam turbine. The design will have to be optimized for wind driven air compressed into a chamber attached to the top or bottom of an appropriately designed Darwin wind collector, then attached to a generator. I'm very excited by this concept, and I believe I hear something like it in Robert's comments during his video. Sure hope I see him demo the idea. I'm finally compelled to warm up my own 3D printer and try some models of my own. I think I can stack rotors between stators with glass ball bearings between them . . .

[@colinkeizer7353]

Put another and another on the stack, inside a Darwin wind collector. What is the maximum number of turbine blade sets that produces useful improvements? What is the optimum distance between turbine blade sets? Wow. So glad we found your channel, Robert. Thanks again for researching and sharing all this.

[@mauriceupp9381]

The blade design is great I like it but I am very curious as to what he was doing with those cooling coils on the directional fan

[@plan9channel7]

Me too.

[@geraldlamontagne8585]

I would imagine that it is for cooling other parts or could be used for adjusting the air temperature to allow for it to be in a enclosure and/or induce a draft flow

[@barryl9441]

Hmm, perhaps I missed it, looking at the video that looks like a bank of LED's.

[@TuttleScott]

they're led's, you can see them light up

[@ThinkingandTinkering]

they were LEDs mate to demo it was working

[@NiteLynr]

That's a serious-looking improvement. I'd love to see a comparison of the output stats though, any chance of a quick revisit? Also, just a though regarding the hub/blade interface: keying the holes and pegs would ensure that the alignment is 100% true every time, especially for a portable version out in the wild. Great job as always, keep it up!

[@andrewalexander4024]

Another great step in maximising the effectiveness of the blades great vid robert

[@peterfelecan3639]

For what's worth, if you wish to harden your propellers even if you print them vertically, as you've done, a simpler solution is to use a different material, e.g. PETG, print at lower speed to give time to fusion the layers and possibly increasing a little bit the temperature. This avoid goo-ing around with glue and such.

[@garyblake4296]

Yup Petg is the answer.

[@johnransom1146]

Couldn’t you cross laminate?

[@davidprocter3578]

On the road down to Mersea Island Essex there is a bungalow on the left hand side of the road, in the front garden there are a considerable number of wind turbines based in the main on bicycle wheels. As far as I am aware non of them do anything other than spin, however they are all different and as I recall one is of a fairly similar design to the one you displayed. I have never spoken to the bloke or had any contact so I cant tell you any more other than It is a while since I drove that route.

[@leostarling5746]

Yes, I used to drive there too, years ago and remember it too.

[@crispycornbread]

Great video. My intuition says it could work even better if the turbines were set up to rotate in opposite directions; but I ain't a turbine engineer so I'm interested in what others think.

[@dmbrookfield]

The russian KA-52 helicopter already does this

[@chrisjoyce6321]

Great to see you back onto wind power generation. Was getting a little confused with the bellows thread.

[@ThinkingandTinkering]

bellows do go with wind turbines mate - good for energy storage and transmission and use

[@marcfruchtman9473]

Great Video. I fully expect 6 blades to perform better at lower wind speeds, but as you stated, as the wind velocity increases the performance would level off... I am curious how much the "offset depth" affects the performance... so I would really like to test the performance of the offset vs just 6 blades in the same plane. You are absolutely correct that publicly posting your invention eliminates the possibility of patenting the invention (as far as I know). However, it doesn't prevent this person from manufacturing this product!

[@NZHippie]

It's pretty obvious that the blades have been doubled ergo an increase in speed ... Another very practical example of physics at work Robert...

[@wannabemgtow2540]

I'm glad you said that if I put a video out on my idea then it becomes public domain, I have an idea that only share one person so I still might keep it to myself.

[@SoundzAlive1]

Hi Rob, You did not mention what would happen if you add another layer. So three sets of blades separated. I see what you are saying about being in the same plane it would be more like a disc and restrict air flow but adding more sets of blades in your arrangement might not reduce speed and increase torque. André in Sydney

[@HeartmindUK]

Hey Rob, love your work. Thanks so much. Question: how would this blade design and set up work for a micro-hydro turbine system? Would it not work the same in generating better performance so could be used in a small stream?

[@MagicianMan]

Surely that design lends itself really well to having the motor installed in the middle? By doing this you also reduce the angular loading on the bearings that must surely occur when having 2 sets of blades projecting forward of the motor?

[@stephenpearce3880]

Hi Robert, under KZbin t&c's you can repost and show any other videos from youtube provided you add adfitional value, such as commentary or additional information. This is not generally known, but it accurate. So you can show the original video, if it was hosted on YT

[@ArcAiN6]

Two points here: 1) There's no need to print the blades vertically, in fact, you can print them at literally ANY orientation. Just clean them up after the print, smooth them out, and use the packed-salt powder method to anneal them (stronger bond, smoother surface) 2) I feel there are glaring flaws with this experiment. I don't think it's an accurate method of testing, and the results may be skewed in several different ways. If you were to reproduce this experiment within a closed chamber, using a proper collimator, i'm pretty sure you'll find that the turbine doesn't in fact spin faster, but rather, it accelerates faster. This is because no matter how much surface area you give the device, it can only go as fast as the air can pass over the blades and impart their energy. There is a diminishing return between surface area, and mass in this context. The more blades you have, the more mass you have to move, and thusly, the energy required to move the fan is increased. Yes, the device will accelerate faster, but it's top speed (how fast it can actually go) is directly proportional tot he energy imparted to it. You're effectively trading collected energy for faster acceleration, and then trading even more energy collected for mass, and because of these trades, you'll not be gaining energy collected from slower, less powerful wind. Effectively, you'll be operating at a net loss, not a net gain.

[@charleselertii6187]

Hello Robert. While the fan demonstration served its visual purpose for the camera, i think you would need to have more air space axially behind the aft end of the turbine blades so that the air would have room for flow thru without blockage and blow back from the cabinets which are close behind the turbine now.

[@ThinkingandTinkering]

i agree mate - we have had this outdoors but i needed the set up to demonstrate the idea

[@petewright4640]

Just to set Robert straight on this: When the turbine is spinning very slowly the blades are effectively stalled (wrong angle of attack) and so they generate very little torque. The three blade version was unable to generate enough torque to overcome the bearing friction when turning at low speed and so could not reach the speed necessary for the blades to become efficient. The six blade version could overcome the bearing resistance sufficiently to spin up the rotor and so enter the rev range where the blades became efficient. This means that if there was less bearing friction then, once at proper speed, the three bladed version could well be more efficient. Blades can be designed to be for high speed rotors, with few blades, or low speed with many blades.

[@themeek351]

I was thinking about two sets of blades in front of the generator and two sets behind! This setup might not need a tail fin, but I suppose two half spiral side wings to help guide the wind into a twist while also keeping it aligned with the wind direction!

[@MrTubeuser12]

I think tapering the blades in your design gives you less torque, and thus less overall power, to the hub, in the video, the blades are straight so there's more surface area and so more "push" at the furthest point from the hub which gives you more torque that can be geared up to make the generator run faster, also you'll notice the blades are curved, this can help with efficiency, PC fans are designed liked that for that reason. I wonder what difference having the fans contra-rotating would make, if any ?

[@maquabear5242]

I truly love your content. Keep up the good work. Please look into this venturi effect on a wind turbine.

[@ThinkingandTinkering]

cheers mate

[@aarondingus3548]

Great work as always! Thank you.

[@stewartpalmer2456]

If you are using PLA, you can also try and alcohol dip and dry. This will melt the layers together. ABS requires an acetone dip.

[@MikePreston-darkflib]

I think you'll find that only at low speeds is it more effective... Blades are designed for specific windspeeds, swept area and tip speed ratio. You have essentially taken blades designed for higher windspeed, doubled them and assumed that it has simply improved the turbine generally... You will find that at the higher end, the efficiency will plummet as betz theorem shows that you can only extract a certain percentage of the available energy. There is a great book by hugh piggot called windpower workshop. I believe he may also do courses at CAT in Wales still.

[@alastairwhite8683]

Brilliant, I wonder what would happen if you put another layer on 🤣👍

[@ThinkingandTinkering]

Good question!

[@bernardmouchet2855]

wahoo! Just,, Wahooo! Many thanks doc....

[@leonmccarty9430]

To continue on the thermal tower compost generator, it would increase air flow using banewlys theory. Where fluids flow faster as a pipe narrows dropping the pressure. So a cone with the heating elements going around it at the bottom of the tower can be the first stage increase. Then a cone shape narrowing of the tower's passage may increase the flow. Same with the down flow side. You see sir, the compost pile heater can run without the worry of outside parable. Add a second compost pile, for when the first one needs refreshing. Enjoy this challenge!

[@jesterblackguarde8464]

I feel like a proper test would be to compare the output of the 6-blade turbine to the combined output of two 3-blade turbines.

[@ThinkingandTinkering]

for sure

[@davidlockledge7879]

Please try it and share the results.

[@HayashiMasahiro]

I can see this being used in a wind wall, but I'm not sure how many sets of fans should be in each segment. Two should be good going off this video, but not sure if more would be a great increase or only a negligible return. Or maybe a wind cube instead of a wind wall? Hmm, probably not. Just saying the first things that pop in my head without really thinking about it. Anyways, thanks for sharing Rob, really gets the ideas forming.

[@neilgillies6943]

Surely, this is just the same as a jet turbine compressor set in reverse? They are all stacked a distance behind each other on the compressor shaft.

[@WesternIronwoks]

you could put more groups of blades on that and gain more from the wind but that would require testing to see what spacing would be needed. I wonder if it would act like a jet engine and stators would help redirect the wind flow after hit by a set of blades. maybe even counter rotating blades. just a few thoughts.

[@karljay7473]

It looks as if the 2nd set of blades is using the wind pushed off the 1st set. Adding some smoke streams should show the flow pattern. IIRC, jet compressor blades do this.

[@BradKarthauser]

I've got a fiver to pitch in on a fume hood for your Christmas present Robert.

[@acortis]

Nice Rob! This of course bags the question of how much energy is still left in the wake of the turbine. An easy estimate could possibly be made by measuring the wind speed at, say 50cm from the back?

[@stevetobias4890]

Very impressive Rob, also thank you Ben

[@grahamdavid007]

rob - could u just reverse the 2 fans - stick together - to greatly reduce the gap n see result? could you create a simple 'gap-controller' to find an optimum gap ? great vid thanks

[@chrisstevens2]

Robert, do you think it may be possible to print a part in plastic in a kiln and then drop liquid metal in it to replace the plastic, as an "easy" way to make specializd metal parts? That would be great to see!

[@mark.guitar]

Easier to send them to a specialist casting company.

[@ThinkingandTinkering]

you can buy wax filament for lost wax casting mate

[@OldManSparkplug]

Electroplating over a dissolving filament gives an amazing result as well. I'm Juuuuust getting started down that road.

[@WTF_BBQ]

I've seen something similar years ago. The turbine was made of a long shaft with multiple blades layered like that. It looked more like string with blades attached to it. The performance was very impressive at first glance, but I don't know what happened to it. I think the concept is the same but instead of having a dozen blades, you only have two.

[@petevenuti7355]

Do you also get a performance boost using it as an airplane prop or fan blade? (I've seen a similar design on a automotive radiator fan, but didn't think much of it at the time)

[@stevefrancis4949]

Thought one of your rose or a few of turbines you were going to put on the Darwin were solid and they span well. Plus the peloton one build worked better facing the wind confused

[@paulvdimitry9931]

It would be interesting to see demo with smoke? Is there a critical spacing? Duel generator Ferris Wheels. Note faster isn't always good for generators. If 2000 rpm is a good speed for generators maybe a CVT gearbox ?

[@leonmccarty9430]

Like to see if this works, It would be right up in your format of experiments. Using a compost pile heater combined with a thermal tower, and a small wind trebin to produce electricity. The idea is to have a generator that runs without depending on natural wind flow. If one is concerned with adding heat to the atmosphere, then the up draft can be turned in a slightly extended u ture. Place a misting valve at the second elbow that turns down wounds. This will drive the air flow down, to run a second turbine.

[@victoryfirst2878]

What I would like to know is how much of an increased load the double blades increase the pressure on the wind generator Robert ?? I am just amazed as yourself how well this works fella. Thanks for the heads up.

[@3xblahblah]

I don't have the equipment to try myself, but I was just wondering what would happen if you had 2 separate, contra rotating turbines. Would the airflow from the 1st interfere with the 2nd, or assist ?

[@colrodrick8784]

I consider myself ‘educated’. Thanks Robert. Btw the difference is profound. Just asking… at what point do additional blades spaced as they are no longer making a difference that makes the extra effort worthwhile ? We can all see that there’s a huge difference between versions 1 and 2. Does it continue with a potential version 3? Etc.

[@eeyzas2]

To further explore this, rather than two sets of 3 blades, I'd love to see a stack of 6 blades arranged in a spiral formation with a gap between each blade

[@rbdogwood]

It looks like a useful development and further down ie previous to this, a suggestion was made that maybe 3 layers would be even better. I don't know if it would as my brain is quite old, however jet turbines use multiple discs of blades. That construction might be worthy of investigation. They can also be supported at both ends of the axis.

[@coltenwatkins6058]

Is that PLA? you should try printing PETG if so. Much tougher stuff and the printing temperatures aren't much higher.

[@chrissscottt]

Cool. I can see where you're going with a vertical stack.

[@geoffbuttsworth]

This is reminiscent of the concept of propeller solidity in propeller powered aircraft (piston or turboprop). The concept of solidity, counter-rotating props, blade numbers, chords, etc is well understood by aircraft manufacturers. An advanced text on aerodynamics and propeller design (try the RAF’s AP3456 series for example) may help

[@dmbrookfield]

Anotehr great video. Isn't the number of blades to do with the lift you can produce not that it is blocking after all they are moving. By this I mean turbulence after a blade goes through it's sweep reduces the laminar flow and the lift, offsetting allows more laminar air and so prodcues the lift needed? BTW There are Helicopters that use dual plade systems but they counter rotate. The russian ka-52 Alligator, I have it on good authority that virbration is a big issue, but if that is the counter rotation I have no idea. But a big shout out to you I love watching your videos, :)

[@consaka1]

More blades equals more torque at slower speeds and perhaps a built-in brake for stopping over speeds in high wind conditions.

[@Warp9pnt9]

Makes me wonder, if there's an upper limit (probably) to returns for more stacks of blades. Is there a sweet spot for distance between blades? Does the distance sweet spot vary the more blades are stacked? Then I start thinking of the practicality of the modular gearing system. As-is, this cuts the cog for generators, so you'd need one generator per set of blades, which seems redundant. Need a central axle (with the gen on trailing edge?), where you can stack on more sets of blades, and vary the distance between them, for testing. A really sophisticated rig might dynamically vary the distance between blade sets, even the rotation of the blades, with varying wind speeds. I'd also try different blade designs. The noisier the blade, the more wasted energy. Taking a cue from some popular computer fan manufacturers, I might try some ridges along the short edge of the tip of the blades (as well as dimpled blades - creates a shroud of air which has lower resistance than even the smoothest surface, and potentially even well-tolerates crude application with a rough surface), and maybe even put them into a shroud, maybe with some sort of parabolic cone of sorts. If you see where we're headed, essentially making a simplified turbine. That sucker sure spun surprisingly fast with just the one additional set of blades. It made me worry if those blades might become a hazard and fly apart. Some kind of variable resistance generator, or a clutch to add more generators, might be handy to absorb extra energy. But then rather than the tension stress of centrifugal force, I'd worry about the sheer stress of the blades or maybe even the main shaft. At some point, you can max out the safe operation of each component, and then have to start braking, and shutting down the turbine. But, dynamic controls for each aspect might allow additional energy extraction along each of the individual stress/failure curves or whatever. I'm not an engineer or anything, these are just ideas that pop in my head as I imagine the various forces at play, and all the questions that arise about maximizing energy extraction per unit mass of the blade material and energy invested for manufacturing.

[@michaelrichey8516]

It was connected to the generator - why no volt/amp readings with and without the modification? That would have given a baseline comparison to show the efficiency increase. Logic says twice the blades = double the caught wind, but the rotational speed was quite obviously more than double.

[@ycaglaya]

@Robert; is it possible to test the energy output of the 3 variations? 3 blades, 6 blades with gap and 6 blades without gap…

[@MrZriael]

Anyone else wondering if adding a shroud between the two sets of blades would improve the efficiency further? I’m thinking along the lines of increasing the pressure on the back set of blades by capturing lateral spillage from the first set. Anyone with a more intuitive sense of fluid dynamics got two cents for me?

[@trevorgoddard2278]

This reminds me of the Zipline drone propeller design although that has only 2 blades and a Ballance weight. The theory as I understand it is the faster the blades turn the more the turbulence interferes with the next blade, so by spreading the blades along the axis that turbulence from one blade to the next is reduced and the efficiency is increased. But I would assume adding more layers and/or decreasing the number of blades at each level will run into the law of diminishing returns.

[@chiperchap]

Now that's intriguing. I'm gonna have to watch that again....

[@undernetjack]

It seems like the mechanics found inside a turbojet engine, except that in a turbojet the next row/ring of blades is smaller and smaller as you go further back. The real wonder is why nobody has tried this in commercial wind turbines long before now.

[@mikehughesdesigns]

How many can you stack together and deminishing degrees? 6 blades @ 60, 9 @ 40, 12 @ 30, before it starts looking like a HVAWT on its side?

[@ThinkingandTinkering]

no idea - give it a go and see

[@stevenbeaumont1698]

great Robert i think i have seen something simlar on a aroplane before

[@eastcorkcheeses6448]

Originally i thought it was going to be contra-rotating blades , How large do you reckon this could be while still getting this benefit ..

[@ryanjamesloyd6733]

ok, having just seen the clip, I'm going to guess before I watch the rest- more total blade surface area for the wind to act against- because quite a lot of wind just passes Between the blades, doing Nothing and not being caught. I'm sure this is a thing with tradeoffs. Now lets see what you have to say.,,, Ok, video watched: Well, Rose turbine, or the... that one that cones to a squirrel cage- does it spin faster than those? I'm not seeing, beyond more blades catching more wind, why this is particularly cool? What am I missing here Rob?

[@colleenforrest7936]

I tried printing the blade flat the first time... Still trying to get the support material off😅 Didn't take me long to try it the right way. Could you add more additions? He doesn't need to patent, he just needs to license. I would refer him to Stephen Key

[@ThinkingandTinkering]

oh a patent is a waste of time for him unless he has a fortune to defend it - if it is any good the larger companies will nick it and he will have to try and sue - that will cost him a fortune up front!

[@williammaxwell1919]

Modern commercical propeller driven have up to 6 blades, yet commercial wind turbines have only 3 blades so are using less of the energy. I've played with different concepts to fit more blades as there is a limit to how long a blade can be realistically made

[@justinweatherford8129]

What would happen you placed a series impellers inside of a lightweight enclosure, with a bell nozzle at the inlet? You might need a bigger fin to keep it facing the wind, but you might also receive more output. Yes, I am somewhat basing this on a gas turbine generator.

[@pinballrobbie]

If you use shims between the two blades you can work out the optimum spacing for best results.

[@brendancull8316]

I've just had a thought, as there is two different blades on this, would it lower the Betz limit of the turbine?

[@davidellis1355]

What do you think the optimum spacing between the blades should be ?

[@velcroman11]

I wonder why you didn’t make the fan blades with the graphene plastic?

[@superrodder2002]

A few years ago I saw someone on You Tube that had a long shaft, maybe 10 feet with 6 3 bladed props spaced along it . I thought it was interesting. It was designed to be hung up between any two available points and let the wind do its thing.

[@CelloSounds1]

I wonder whether 3 layers of 3 blades would improve things more again?

[@mauriceupp9381]

Another thought if you were to adjust those blades right or left of that 60° could you control the speed and torque with that propeller??

[@wasunka]

Just curious, have you tried counter-rotating propellers? Has anyone?

[@danedmiston9673]

A two blade turbine rotor using the same blades would be nice to add to the outdoor comparison video.

[@clambert24]

The stl file has an issue and the centre cog isn't complete and a tooth or 2 isn't manifold and won't slice properly. Can this be fixed pleased. Desperate to make this.

[@Rebar77_real]

How about three sets of blades at less degree of separation? At what point is the weight not worth it? With four sets can you cut the blade size in half? Wait a minute is that a backwards jet engine? etc... :D Neat stuff!

[@TuttleScott]

the blades on the demo double stack are about 2x as wide as the single stack.

[@Crispy_Critter]

I know you haven't yet done a lot of efficiency measurements, but how would you compare the effectiveness of your improved tesla turbines (hyperbolic cones) to bladed fans like this?

[@grendel1960a]

interesting, maybe the front set sets the wind up behind itself to improve the efficiency of the second set of blades, the wind is already slightly deflected.

[@peterwiley4383]

Wow, amazing the difference that was made.

[@noaholiverpang5250]

Could it be that the three-bladed turbine is experiencing stall? if both turbines were angled and loaded optimally for efficiency at a certain windspeed then perhaps they would both be spinning similarly... I would assume there is also a tradeoff between the increased torque of more blades with their increased drag. (making more blades better at lower speeds and vice versa)

[@PhilippinesUntold76]

I wonder if a third set of blades or even 4,set behind again, could give even better performance?

[@Smo1k]

That's an enormously increased efficiency... Haven't done the maths, but my "intuition" (also called quick slap-job application of various bits encountered through life) says that the double stack rotates more than 10 times as fast as the single stack.

[@johnskinner7571]

I know you don't read a lot of these posts, have you tried annealing the pla prior to super glue application?