Nice to see it all coming together! As a retired electrical engineer, I am enjoying this series showing how units involving mechanical engineering work, and what they can do. thank you Rob!
I've always wondered, do you think it's possible to have contra-rotating blades angled oppositely to each other, with the 'stator' containing windings + brushes actually ROTATING opposite to the rotor that contains permanent magnets? Will the drag cancel out any gains? Would they just lock in low wind and be useless? It's a high wind idea!
@@PrivateSi I was thinking exact same thing during the video.. slip rings and brushes would add to build cost and probably steal a bit of torque? So much experimenting to be had here :)
your prototyping is not only advice for others who are thinking of things, but a good workflow idea for those who have the ability to make the end product but have not tested it out first
finally got myself a working printer in the k1 max, so i'll be grabbing your tinkercad files and running with them. thank you, rob. you continue to be an inspiration!
Using the greater length of the part of the cylinder of your diaphragm piston, I converted that into the piston and inserted it into a short length of acrylic tubing. Instead of using the glove, I used a section from an old bicycle inner tube which lined the new piston and stretched around the outside acrylic tube. I reprinted the cylinder to make it solid. The material of the inner tube is butyl. It still needs graphite for lubrication but it's workable and is a cheap way of having an actuator that could exert a few kilos of force in one direction. However it could make quite a good water pump. But if you want a really good water pump look no further than a sink plunger! If you glue a sheet of perspex under it, drill holes for valves and put a crankshaft at the stick end, turn the crank, then for each cycle it could shift around 70ml of water. If that was connected to the wind turbine it could pump water to a tank at a higher level. Of course, in reverse it could still work as an engine or as a hydraulic motor. So if you had 2 sink plungers, as one crankshaft rotated, the pressure transmitted through the hose pipe would go to the other sink plunger, and it would drive the flywheel. A sink plunger is one of those things that one would never consider using, but having watched a good number of your videos, the possibilities certainly leads to some exploration.
Referring to previous videos. Yes, I know you are demonstrating the differential concept, what about putting nodules and serrated trailing edge. It would be interesting to see the difference in output. Thanks for this video. Such wonderful ideas.
Bravo ! ! ! Nice exactly what was needed to make this great ! ! ! Some dimension also need to be corrected. I was reading some studies about this topic, distance from rotors is also very important, swirl angle, dimensions of the rotors, with smaller rotor in front & larger in the back, power peaked with rotational speed diference of N = 0.3, tip speed ration around 3, & hybrid air foil with high lift to drag ration for rear rotor, combining the suction side of the DU 86-084/18 with the pressure side of the SD 7003 demonstrated superior lift to drag. Bravo ! ! !
I am curious to know if laminar flow is more efficient than turbulent flow? Maybe laminar flow can be created by the first blades for the second blades to use?
@@vylbird8014 Interesting. I look forward to it, if you get around to it. According to Wikipedia regarding downwind rotors: "The main drawback is that the load on the blades changes as they pass behind the tower, increasing fatigue loading, and potentially exciting resonances in other turbine structures." I imagine that this is sort of what you're talking about.
@vylbird8014 while passing through 1st prop, some of the airflow energy is converted into an axial swirl, and also turbulence. A following contra-rotating prop (with blades set at the correct *different* angle of attack) should recover most of energy within the axial swirl. But it will also be subject to extra vibration due to the extra turbulence.
Another great instalment as always. However, I might have missed something here. Are the blades not ment to be off-set by 60 degrees in these duel rotor machines, enabling them to make use of the wind energy not taken by the forward set of blades? My initial thought is it’s inevitable the blades will at some point or another be in perfect alignment meaning the rear blades take no, or at least limited energy from the wind. Thanks in advance for any clarification. Other than that, I may well make one for the hell of it.
Great demo, one potential downside is added complexity versus a single, larger machine, or even two smaller ones. The simpler the better, is a good rule for anything that resembles infrastructure. It gets complex enough no matter what.
I like how you explain your train of thoughts in these videos. But I am somewhat perplexed that often the comments are full of the very things you're addressing as shortcoming in the video. But here we are 😊
hi Robert you don't need to shrink your diff gear to match your 1: .25 ratio just increase you blade diameter until the ratio of diameter to spacing is reached, unless you 3d print bed size wont allow it , which ever is simpler or practical.
Another excellent job & the generator can be mounted on the pole with an appropriate 90deg drive & ratio to the generator. This makes the slip rings redundant.
Wouldn't this work best if the rotors were contra rotating? The first rotor is going to deflect the air, a contra rotating second rotor should be able to capture that. I further assume that in a wind farm this would increase overall efficiency because the wind direction after the wind turbine is similar to it before.
Well this looks like a good idea for the trouble of fixing wind turbines as the generation could be floor level from the shaft. Obviously there must be inefficiency with the gearing, but should off shot by efficiency of the two blade system
Spur gear differentials are so much better suited to high duty cycle - they are used in the few "successful" coaxial helicopters (single or dual turbine input to the rotors - torque balance - yaw controlled..)
Copier technician approved! We see a LOT of similar mechanisms! . Another advantage... If the power take-off is mounted "vertically, the generator unit could be positioned low on the pylon which may reduce the mass and torque at the top of the unit?
I would be concerned about how the forces redistribute themselves when the differential casing starts to experience drag from the eddy currents of the generator. Differentials have an issue in that if the casing is held completely rigidly, then the two other shafts will turn in opposite directions. If the two differentially-connected propellers experience different amounts of force, then the slower propeller will impart some drag. Ithink I would need a model like you have made to experiment with the concept. It might be necessary to use some form of differential locking or a slip differential to counteract this.
@@ThinkingandTinkering Certainly sir! Apologies. I think I used incorrect terminology. I wrote casing, but I meant to refer to the combined ring gear and carrier that encloses the three conjoined bevel gears. I was in a rush to get out the door this morning. Assume that the two propellers have identical weights and are pitched such that axial airflow will impart a similar amount of rotational force to each propeller such that if the ring gear, carrier, and planetary gear were not present, then the propellers would try to rotate at a similar speed, co-axially. If the ring gear and carrier are allowed to rotate freely, then the ring gear and carrier have a rotation rate that is the average of the rotation rate of each propeller. For example, if one propeller has 12 rpm, the other propeller has 10 rpm, then the ring gear and carrier has 11 rpm. If the ring gear and carrier are not allowed to rotate, then the two propellers hardly rotate because the planetary gear makes them fight against each other. For example, if one propeller has 12 rpm, the other propeller has 10 rpm, and the ring gear and carrier are brought to a stop, then the propeller that had 12 rpm might rotate in the expected direction at a very slow rate (e.g. +5/6 rpm), the propeller that had 10 rpm might rotate backward at an even slower rate (e.g. -1/6 rpm), and the ring gear and carrier would have 0 rpm. (I just pulled those RPM out of the air.) If the ring gear and carrier are allowed to rotate, but experience rotational resistance (as might happen while they are connected to a generator), then would the two propellers fight against each other through the planetary gear (similar to above) in an amount that is proportional in some way to the rotational resistance experienced by the ring gear and carrier, since it would be in a state somewhere between the two examples above?
@@Kargoneth the force on the down wind rotor is bound to be less mate as some energy has already been extracted - so if the gear wasn't there the forces would be unbalanced - one way to counteract this might be by changing rotor size by a proportion - that aside - i might have this wrong but it seems like you might be describing a planetary gear but not the action of a differential
@@ThinkingandTinkering I am trying to use the terminology on the Wikipedia differential mechanism page. It calls the free-spinning bevel gear (that is affixed to the carrier perpendicular to the axis shared by the three other gears) a planet gear. It calls the co-axial/co-linear bevel gears (that are connected to the planet gear and to the pair of co-linear shafts that extend out of each end of the carrier) sun gears. I may be simulating things in my head incorrectly, but I also seem to be having trouble describing what I am imagining in a way that is understandable. I think I would have to actually try to do what I am thinking, rather than describing it. Oh well. I can certainly see one advantage to this setup in that if something were to cause one propeller (and sun gear) to stop turning while the other propeller (and sun gear) continued turning, then the planet gear, carrier, and ring gear would also continue turning and generating power. Thanks for responding, Robert.
@@Kargoneth no prob mate - shame we are not sat down over a beer discussing this I am sure we would reach a common understanding - that - to be honest can be quite hard when just using the comments section lol - cheers
Awesome video Robert. … very inspirational. Combining power should occur, but I’m thinking that the rear propeller could also spin backwards. Even if it’s not obvious, a loss of power might be see. I’m wondering if the rear blades need a greater pitch than the front - given the slower speed. I guess the only way to find out is to test it at extreme pitches, I think. You have inspired me to design a better pool cover gear system. I’m thinking about using lantern gears made from 3d printing.
seems like you could make some kind of governor to control the blade pitch to balance the front and back or even use a computer to control it via torque sensors.
i really like the idea of a wind generator where the actual dynamo is stationary and at the base of the pole and the turbine is merely turning a driver shaft and a differential could help with rotating around that driver. maybe copy the differential of a car's drivetrain? or was that already tried?
Could you substitute the mechanical differential with a bit more complex electronics? My idea is to put the magnets on one set of blades and the coils on the other set. By getting them to rotate in counter-directions, you get power output by having either one rotate or more if they both rotate. To get the power out of the coils, you would need a bit more complex wiring, but a set of cheap brushes will do for this model size.
Another comment regarding the PLA, have you ever tried iron-impregnated PLA in one of the generator designs? From my understanding if the core inside each copper coil contains ferrous material it improves generator efficiency greatly. There is also a stainless-steel impregnated PLA (both claim roughly 60% metal content), but I'm not sure if the type used is ferromagnetic. Would be interesting to build a gen using the iron PLA, perhaps only in the coil cores due to its substantially higher cost.. I would imagine ordinary PLA and the metal PLA would bond just fine so the filament could be switched mid-print.. but depending on design that could be very wasteful on the filament. Something interesting to consider :) I see "protopasta" makes metal PLA and it's available on Amazon.
Forgive me for my ignorance, but if instead of your bulky accumulator differential( which is amazing)...what if you allowed the device to rotate. It might be slightly less efficent than the add diff, but one blade slower should translate into angular momentum around a fixed point. I believe you can put a simpler version of your add diff at the bottom on the rotating shaft. So if you put your generator on a 10M tower, you can have your diff down below the sweep of the blades .
I wonder if having the second turbine a little bit larger the the first would be a simple way to counter the rpm asymmetry. Might not need to be that different in size to match them 5-10% perhaps. Your videos always spark more ideas, keep them coming Rob :)
@@ThinkingandTinkering Sir, I have read Archimedes made a magnet wheel device where Gearing and magnet faces of similar pole interaction reduces Drag, Exploiting Timing and magnetic Repulsion... Eighties a Asian man made these, coupling many generators on One Motor. Don't know if you saw Archimedes example, but with 3D printer I think it's a good project, just saying it might make 1 windmill or waterwheel power 2+ generators at once..
I have done it mate - what you are talking about are magnetic gears and they can be arranged as a planetary gear system easily - but is definately a good idea thanks for sharing
@ThinkingandTinkering 1 thought, one tiny mag peer tooth, North side Out for tiny push of Both interacting gears interacting. You a Tinkerer, Archimedes had Gears on shafts mag wheels on opposite side of shaft, but I know 3D print can put mags right in gear Tooth for continuous force. Chinese man used Lathe which was time and impressive, 3D printer, Modeling program few hours..
@@dSquared0162 i drew it in tinkercad mate - it is the bevel gear from the drop down menu - if you type gear in the search bar it is the 3rd down on the right hand side - it is module 2, 22 teeth, pitch angle 30 angle 45 and height 10 there is an 8mm hole in the centre. Then I just exported it as stl
Another great thought provoking video.I just have one request. Can you please use different colored filaments? All white doesn't come across on video and it's difficult to see the mechanism clearly.
I use a lot of white filament, myself, but it doesn't come across on video very well. Try printing the gears, etc in different colors that contrast with each other. They will show up better on video and make it easier to see what you are doing. Before I went back to school for my electronics degree, I was a graphic artist so I might be a little too aware of things like this. 😊 But I love your content. I do miss your lab, though.
and what about rotors turning in opposite direction - one turns rotor and other turns stator which is connected through slip ring contacts. that would increase RPM on alternator.
Why not adapt the angle of attack on the two rotors differently to accomodate to the power loss. Not sure if it would be easy to measure if the angle "is good" then
What about an ofset of the two rotors ? Not sure which way the pair would best rotate but im thinking of how migrating birds save energy by slipstreaming. Could this be worth doing, i dont know?
Suggest, add a Benbini on-line. Use both sides of Coil, setting one side North-pole and South pole aligned, add pick-up coil to receive from magnet wheels, or D.C. Gene as Bearing for mag wheel and Gene simultaneously. "LIDMOTOR" CHAN has build vids on these, uses one on his Sail boat actually.
Been traveling for the past couple of months, finally begin printing the parts for your portable generator, decide to switch to PETG from PLE + because of it's superior durability, spend the next two days of fail, coming to the conclusion I'm a nube who forgot his KISS principle, switch back to PLE +, because that works and I'm making a prototype that I will no doubt muck up as a first go, print one of the gears successfully, look out the window, there's no wind, and decide to see what Robert is up to...I'm beginning to feel a bit like Dorian Gray's portrait.
@@ThinkingandTinkering Short version, Northern California to the coast, Southern Cal, to Palm Strings, to Tuscon, to Utah, to Nevada, to SF, to San Diego, there and back again. The highlight was drowning my sorrows at the absence of pubs and pints in the local wine bar. Sitting next to an retired electrician who thought I was quite mad for building a generator with a 3d printer and winding my own coil - serpentine, thank you very much, we bonded over my ignorance, enthusiasm, and tipped a glass to you.
You can run a, Joule Theaf/Joule ringer. If the lights go out, in a Storm at least you got Light 😮... Dial it in charge cell phone... Real small Sand battery to Stirling cycle gene😅😅
You can quite easily run a 240v 1 watt led bulb very brightly with a hv stepup transformer and your 2x aa 1.2v batteries so great bit of free energy when the wind is blowing 👍
@@johnwynne-qx6br Ever make a Joule Ringer/TheaF inverter? Transistor, Resistor, Bi-filar Coil, Either Cored or coreless, Toroid, Rod or Pancake works. Old speaker wire, Romex for Home even thin Bi-filar from a broken earphones. These tiny inverter's are pretty great, 2n2222, 2n3907, 2n3055, 2n7401 almost all transistor's work. 2n3055 can handle Big coil though. using these I take a Solar lamp thing for yard, replace the bulb with inverter and buld on inverter, getting twice the light and run time as before. Put on window sill, makes a automatic light. Inverter is great emergancy thing.. On my channel I show diagram...
What about making a hydraulic fluid differential. To produce electrical power and heat ? It would be self lubricating at the very least and with proper design it could possibly charge a battery and heat a home simultaneously.
spring mass damper analogue is inductance capacitance resistance there should be an electromagnetic equivalent to a differential irrespective two generators seem to go on the shaft line by the looks given physical distance to prevent or limit somehow interacting electromagnetism and each suitably sized equally a differential is perhaps as good if not better in some or all respects the blades however are another problem much in the way it is as they pass the tower (resonance vibration condition)
Mars helicopter Ingenuity also used double propellors
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Actually you don't need any gears. You can make coils spinning on first rotor and magnets spinning on the opposite rotor gaining much higher combined speed.
Fun mechanics but I'd like to see someone test a contra-rotating wind turbine where the 'stator' actually moves, but in the opposite direction to the rotor. Blades need to be oppositely angled. the rotating 'stator' has the windings and brushes while the rotor has permanent magnets. I'd just like to see if it produces more power, or if the attraction between the stator and rotor poles slows each blade down to cancel out any gains or makes it worse than a normal turbine. It's even worse for birds but should be quieter.
@@ThinkingandTinkering .. lack of time and skills... The only 3D CAD package I've managed to master enough is Wings3D which is not parametric so no use for making real models. Fun, easy to learn and powerful in its own way, but old now. Great for designing round things like turbines, just not printing them. Attaching it to the shaft is probably the sticking point, and housing bearings.
@@ThinkingandTinkering .. No way, that's some online megacorporate thing so two reasons I'd never use it.. I'll learn FreeCAD at some point as its offline and free, open source.. Not for this, but for a more interesting 'piston turbine' ICE + heat engine combo that's already wasted too much of my time, but good enough to make patent drawings. No way would I put a design I want to patent on some online corporate platform. They probably automatically own everybody's designs!!?!
It is possible, if you have a public library accessible to you, that they have 3D printers available for a nominal fee. I've seen some that charge something like 6 cents per gram of filament. You can forego the cost of buying the printer or full spool of filament yourself.
@@staycurious8650 I wouldn't assume this is impossible. 3D printers have been around for so many years and some older models are so inexpensive it's quite possible you may find a resource like this. If you're near one of the more populous cities like Cape Town there must be some place, or at least someone who would "rent" their printer for a nominal cost. It is after all a way for them to make money with their printer so they wouldn't be secretive about this. If you take this a step further YOU could be the one offering a service like this to others, end up paying for that printer with money from people looking to print something.
I'm not saying it's not accurate, but how come I have never seen one? I live in Sweden and I think we have a great deal of wind turbines. Companies are usually very greedy, so how come it isn't anywhere here.
Just use the bigg ellegoo they send you. Then make it in pet.g. Then Just print the balbearings. In abs. It wil meet the wether. Whit no problems. And its big. You can also use superglu to wipe the whole thing down.
@@ThinkingandTinkering I am wondering if an impeller shaped fan / centrifugal fan sitting in a ' sleeve ' shaped just right for air flow to increase around it and then flow through a small tube behind the centrifugal fan leading to another propeller type fan could generate more energy . or energy at all . haha . Have you seen the drones that fly using centrifugal fans ?
differentials are singularly the most common mechanism with around 200 years of research behind them and are perhaps one of the most fault free mechnaisms
well if that is the case Eaton are just using a spur gear differential and calling it true trac - I didn't design the differential mate - i just modeled it
@@ThinkingandTinkering Just mentioning it has a similar action to something car guys might know. I wish I had models like that as a youngster. Cool video, thank you!
I see a problem with your design. Not a serious one at this small prototype scale, but it's going to come to bite you when you scale up. Every time the down-wind blade passes by the shaft, it's going to briefly dip into the wake of the shaft and experience a momentary reduction in force upon it. That is going to make the blade flex slightly every rotation, which is going to 1. Seriously reduce blade life and 2. Make lots of noise. This is why all rotating HAWTs place the blades in front of the shaft.
I think this twin rotor is dead in the water and not worth pursuing, It it was then we'd be using it. If you study airflow then you'll realise that what comes out of the back of a turbine is a random mess of air and incapable of powering another one to any positive degree. It will actually be worse than that though and hinder the flow through the first one by having it's exiting energy reduced. I hold you in such high regard that (and i've said it before) you are good enough to be on TV, but the one annoying thing is that you never see your projects through to the end. If you did that you'd be a much more powerful resource. I wish I lived near you, i'd be popping round to team up and make some of these things and see if they work in reality!
Umm - what's the point of putting the differential in?? You start with explaining the issue relating to the two sets of magnets, and then you proceed to create a dual turbine without the wiring OR magnets. What you end up with is a windmill, not a wind generator
umm indeed - do you not see that the take off shaft is where the generator will be? I don't want to be rude mate but you do need to think it through a little
@ThinkingandTinkering I don't doubt the effectiveness of the differential, but there is a good reason why they can't put wind turbines close together. I believe the materials could be better used on a bigger turbine or another turbine in another location.
ah well we all have our ideas mate lol - I wasn't being rude by the way the research on dual rotors and their effectiveness set against cost is pretty interesting reading
Nice to see it all coming together! As a retired electrical engineer, I am enjoying this series showing how units involving mechanical engineering work, and what they can do. thank you Rob!
cheers mate
I've always wondered, do you think it's possible to have contra-rotating blades angled oppositely to each other, with the 'stator' containing windings + brushes actually ROTATING opposite to the rotor that contains permanent magnets? Will the drag cancel out any gains? Would they just lock in low wind and be useless? It's a high wind idea!
@@PrivateSi I was thinking exact same thing during the video.. slip rings and brushes would add to build cost and probably steal a bit of torque? So much experimenting to be had here :)
your prototyping is not only advice for others who are thinking of things, but a good workflow idea for those who have the ability to make the end product but have not tested it out first
nice point mate and well made - cheers
Great model for Proof of Concept Robert!!
Thank you very much for sharing your enthusiasm and knowledge!!
Andréa and Critters. ...XxX...
cheers Andrea
finally got myself a working printer in the k1 max, so i'll be grabbing your tinkercad files and running with them. thank you, rob. you continue to be an inspiration!
that is awesome to hear mate
Such a treat to watch your videos. Thanks Robert!
Glad you like them!
a veritable work of art ,with a large helping of practical science .
cheers mate
Bob, delighted to come full circle back to wind generator! On the edge of my chair waiting for some wind. ;)
I think to do good wind turbines you need to know your mechanics mate - but it always come full circle lol
I have lots of wind.
@@tomellis4750 😆
As awesome as always! ⭐
Thank you! Cheers!
Thanks for sharing
Thanks for watching!
A love it when a plan comes together... 😎👍
lol
tthank you Robert, have a great weekend
You too
Using the greater length of the part of the cylinder of your diaphragm piston, I converted that into the piston and inserted it into a short length of acrylic tubing. Instead of using the glove, I used a section from an old bicycle inner tube which lined the new piston and stretched around the outside acrylic tube. I reprinted the cylinder to make it solid. The material of the inner tube is butyl. It still needs graphite for lubrication but it's workable and is a cheap way of having an actuator that could exert a few kilos of force in one direction. However it could make quite a good water pump. But if you want a really good water pump look no further than a sink plunger! If you glue a sheet of perspex under it, drill holes for valves and put a crankshaft at the stick end, turn the crank, then for each cycle it could shift around 70ml of water. If that was connected to the wind turbine it could pump water to a tank at a higher level. Of course, in reverse it could still work as an engine or as a hydraulic motor. So if you had 2 sink plungers, as one crankshaft rotated, the pressure transmitted through the hose pipe would go to the other sink plunger, and it would drive the flywheel. A sink plunger is one of those things that one would never consider using, but having watched a good number of your videos, the possibilities certainly leads to some exploration.
that is impressive work mate - and i am doubly grateful you shared it - brilliant ideas - thanks so much
Referring to previous videos. Yes, I know you are demonstrating the differential concept, what about putting nodules and serrated trailing edge. It would be interesting to see the difference in output. Thanks for this video. Such wonderful ideas.
i Have done videos with tubercles on the blades before mate
Bravo ! ! ! Nice exactly what was needed to make this great ! ! ! Some dimension also need to be corrected. I was reading some studies about this topic, distance from rotors is also very important, swirl angle, dimensions of the rotors, with smaller rotor in front & larger in the back, power peaked with rotational speed diference of N = 0.3, tip speed ration around 3, & hybrid air foil with high lift to drag ration for rear rotor, combining the suction side of the DU 86-084/18 with the pressure side of the SD 7003 demonstrated superior lift to drag. Bravo ! ! !
nice mate - an excellent post thank you for taking the time to make it
I am curious to know if laminar flow is more efficient than turbulent flow? Maybe laminar flow can be created by the first blades for the second blades to use?
Interesting. I've often wondered why wind turbines didn't have dual propellers.
some do - it can take time for new ideas to filter through
I'm about to make a long comment explaining why, but the short version is 'propeller downstream of pole experiences stress.'
@@vylbird8014 Interesting. I look forward to it, if you get around to it.
According to Wikipedia regarding downwind rotors: "The main drawback is that the load on the blades changes as they pass behind the tower, increasing fatigue loading, and potentially exciting resonances in other turbine structures."
I imagine that this is sort of what you're talking about.
@vylbird8014 while passing through 1st prop, some of the airflow energy is converted into an axial swirl, and also turbulence. A following contra-rotating prop (with blades set at the correct *different* angle of attack) should recover most of energy within the axial swirl. But it will also be subject to extra vibration due to the extra turbulence.
Great concept, good to see you back in full swing with your ideas and prototypes 👍
cheers mate
👍 one step at a time.
absolutely
thank you mate i always enjoy your shows , i think our schools could use you . cheers mate terry
cheers mate
Another great instalment as always. However, I might have missed something here. Are the blades not ment to be off-set by 60 degrees in these duel rotor machines, enabling them to make use of the wind energy not taken by the forward set of blades? My initial thought is it’s inevitable the blades will at some point or another be in perfect alignment meaning the rear blades take no, or at least limited energy from the wind. Thanks in advance for any clarification. Other than that, I may well make one for the hell of it.
oh make one for the hell of it mate lol
Great demo, one potential downside is added complexity versus a single, larger machine, or even two smaller ones.
The simpler the better, is a good rule for anything that resembles infrastructure. It gets complex enough no matter what.
true enough mate
Agreed, simpler is more Accessable
I like how you explain your train of thoughts in these videos. But I am somewhat perplexed that often the comments are full of the very things you're addressing as shortcoming in the video. But here we are 😊
somepeople just fon't listen - or they comment before they watch the video - the balance of that quite a lot of people share some aweome ideas
@RobertMurraySmith thanks for the heads up on why you have been doing diffs. Can't wait to see the protocol move in the wind.
cheers mate
Congrats on 500k subs Rob, you've come a long way, nice to see the channel becoming more and more popular ! 1m subs in no time now.
hi Robert you don't need to shrink your diff gear to match your 1: .25 ratio just increase you blade diameter until the ratio of diameter to spacing is reached, unless you 3d print bed size wont allow it , which ever is simpler or practical.
either way is good mate - as you point out - whatever suits your printer
@@ThinkingandTinkering
There's no reason you couldn't print each blade in 2 parts and clip them together?
Very clever
cheers mate
Another excellent job & the generator can be mounted on the pole with an appropriate 90deg drive & ratio to the generator. This makes the slip rings redundant.
nice one
Wouldn't this work best if the rotors were contra rotating?
The first rotor is going to deflect the air, a contra rotating second rotor should be able to capture that.
I further assume that in a wind farm this would increase overall efficiency because the wind direction after the wind turbine is similar to it before.
yep - motion is all relative
Well this looks like a good idea for the trouble of fixing wind turbines as the generation could be floor level from the shaft. Obviously there must be inefficiency with the gearing, but should off shot by efficiency of the two blade system
nice one mate cheers
Spur gear differentials are so much better suited to high duty cycle - they are used in the few "successful" coaxial helicopters (single or dual turbine input to the rotors - torque balance - yaw controlled..)
I didn't know that - very interesting thank you mate
Copier technician approved!
We see a LOT of similar mechanisms!
.
Another advantage...
If the power take-off is mounted "vertically, the generator unit could be positioned low on the pylon which may reduce the mass and torque at the top of the unit?
awesome mate
Awesome as always!
Next video will be you 3D printing your own wind-tunnel.
That would be cool!
This series is inspiring me to get my first 3D printer. Best check out these files before some patent troll gets busy :)
i do find them very very useful mate
I would be concerned about how the forces redistribute themselves when the differential casing starts to experience drag from the eddy currents of the generator. Differentials have an issue in that if the casing is held completely rigidly, then the two other shafts will turn in opposite directions. If the two differentially-connected propellers experience different amounts of force, then the slower propeller will impart some drag. Ithink I would need a model like you have made to experiment with the concept. It might be necessary to use some form of differential locking or a slip differential to counteract this.
yoiu know it will be in a nacelle right?
@@ThinkingandTinkering Certainly sir!
Apologies. I think I used incorrect terminology. I wrote casing, but I meant to refer to the combined ring gear and carrier that encloses the three conjoined bevel gears. I was in a rush to get out the door this morning.
Assume that the two propellers have identical weights and are pitched such that axial airflow will impart a similar amount of rotational force to each propeller such that if the ring gear, carrier, and planetary gear were not present, then the propellers would try to rotate at a similar speed, co-axially.
If the ring gear and carrier are allowed to rotate freely, then the ring gear and carrier have a rotation rate that is the average of the rotation rate of each propeller. For example, if one propeller has 12 rpm, the other propeller has 10 rpm, then the ring gear and carrier has 11 rpm.
If the ring gear and carrier are not allowed to rotate, then the two propellers hardly rotate because the planetary gear makes them fight against each other. For example, if one propeller has 12 rpm, the other propeller has 10 rpm, and the ring gear and carrier are brought to a stop, then the propeller that had 12 rpm might rotate in the expected direction at a very slow rate (e.g. +5/6 rpm), the propeller that had 10 rpm might rotate backward at an even slower rate (e.g. -1/6 rpm), and the ring gear and carrier would have 0 rpm. (I just pulled those RPM out of the air.)
If the ring gear and carrier are allowed to rotate, but experience rotational resistance (as might happen while they are connected to a generator), then would the two propellers fight against each other through the planetary gear (similar to above) in an amount that is proportional in some way to the rotational resistance experienced by the ring gear and carrier, since it would be in a state somewhere between the two examples above?
@@Kargoneth the force on the down wind rotor is bound to be less mate as some energy has already been extracted - so if the gear wasn't there the forces would be unbalanced - one way to counteract this might be by changing rotor size by a proportion - that aside - i might have this wrong but it seems like you might be describing a planetary gear but not the action of a differential
@@ThinkingandTinkering I am trying to use the terminology on the Wikipedia differential mechanism page. It calls the free-spinning bevel gear (that is affixed to the carrier perpendicular to the axis shared by the three other gears) a planet gear. It calls the co-axial/co-linear bevel gears (that are connected to the planet gear and to the pair of co-linear shafts that extend out of each end of the carrier) sun gears.
I may be simulating things in my head incorrectly, but I also seem to be having trouble describing what I am imagining in a way that is understandable. I think I would have to actually try to do what I am thinking, rather than describing it. Oh well.
I can certainly see one advantage to this setup in that if something were to cause one propeller (and sun gear) to stop turning while the other propeller (and sun gear) continued turning, then the planet gear, carrier, and ring gear would also continue turning and generating power.
Thanks for responding, Robert.
@@Kargoneth no prob mate - shame we are not sat down over a beer discussing this I am sure we would reach a common understanding - that - to be honest can be quite hard when just using the comments section lol - cheers
Looking forward to the wind coming and test results.
cheers mate
Awesome video Robert. … very inspirational. Combining power should occur, but I’m thinking that the rear propeller could also spin backwards. Even if it’s not obvious, a loss of power might be see. I’m wondering if the rear blades need a greater pitch than the front - given the slower speed.
I guess the only way to find out is to test it at extreme pitches, I think.
You have inspired me to design a better pool cover gear system. I’m thinking about using lantern gears made from 3d printing.
i have already made this in a different format mate it doesn't spin backwards
seems like you could make some kind of governor to control the blade pitch to balance the front and back or even use a computer to control it via torque sensors.
sure it's a way to go
i really like the idea of a wind generator where the actual dynamo is stationary and at the base of the pole and the turbine is merely turning a driver shaft and a differential could help with rotating around that driver. maybe copy the differential of a car's drivetrain? or was that already tried?
Could you substitute the mechanical differential with a bit more complex electronics?
My idea is to put the magnets on one set of blades and the coils on the other set. By getting them to rotate in counter-directions, you get power output by having either one rotate or more if they both rotate.
To get the power out of the coils, you would need a bit more complex wiring, but a set of cheap brushes will do for this model size.
Another comment regarding the PLA, have you ever tried iron-impregnated PLA in one of the generator designs? From my understanding if the core inside each copper coil contains ferrous material it improves generator efficiency greatly. There is also a stainless-steel impregnated PLA (both claim roughly 60% metal content), but I'm not sure if the type used is ferromagnetic. Would be interesting to build a gen using the iron PLA, perhaps only in the coil cores due to its substantially higher cost.. I would imagine ordinary PLA and the metal PLA would bond just fine so the filament could be switched mid-print.. but depending on design that could be very wasteful on the filament. Something interesting to consider :) I see "protopasta" makes metal PLA and it's available on Amazon.
Forgive me for my ignorance, but if instead of your bulky accumulator differential( which is amazing)...what if you allowed the device to rotate. It might be slightly less efficent than the add diff, but one blade slower should translate into angular momentum around a fixed point. I believe you can put a simpler version of your add diff at the bottom on the rotating shaft. So if you put your generator on a 10M tower, you can have your diff down below the sweep of the blades .
nice ideas cheers mate
I wonder if having the second turbine a little bit larger the the first would be a simple way to counter the rpm asymmetry. Might not need to be that different in size to match them 5-10% perhaps. Your videos always spark more ideas, keep them coming Rob :)
Different Pitch on fore and aft blades. Slight size and weight difference between..
it is one approach i have seen
@@ThinkingandTinkering Sir, I have read Archimedes made a magnet wheel device where Gearing and magnet faces of similar pole interaction reduces Drag, Exploiting Timing and magnetic Repulsion... Eighties a Asian man made these, coupling many generators on One Motor. Don't know if you saw Archimedes example, but with 3D printer I think it's a good project, just saying it might make 1 windmill or waterwheel power 2+ generators at once..
I have done it mate - what you are talking about are magnetic gears and they can be arranged as a planetary gear system easily - but is definately a good idea thanks for sharing
@ThinkingandTinkering 1 thought, one tiny mag peer tooth, North side Out for tiny push of Both interacting gears interacting.
You a Tinkerer, Archimedes had Gears on shafts mag wheels on opposite side of shaft, but I know 3D print can put mags right in gear Tooth for continuous force.
Chinese man used Lathe which was time and impressive, 3D printer, Modeling program few hours..
Robby u da man! three years later and this week I am finally printing! thanks mate! say ,I wanted that tyson type to be my first but can't find it..
awesome mate - have fun - it really canhelp when you get into it - tyson type?
How much energy do you lose with the planetary gearing ?
have a read of the research
That's just awesome! Great job! 👏
cheers mate
@@ThinkingandTinkering Where did you get your 'small bevel' from? Seems to be a problem with it.
@@dSquared0162 i drew it in tinkercad mate - it is the bevel gear from the drop down menu - if you type gear in the search bar it is the 3rd down on the right hand side - it is module 2, 22 teeth, pitch angle 30 angle 45 and height 10 there is an 8mm hole in the centre. Then I just exported it as stl
Seems to be the same one as in your "Craziest Clock Mechanism"... minor size tweak... so I'll use that.
@@dSquared0162 yeah i reuse loads of designs - saves time mate
Would the “Torsen” design work well in this situation? Maybe to prevent stalling?
anything would mate - even a standard bevel gear diff - they all have their advantages and disadvatages
Another great thought provoking video.I just have one request. Can you please use different colored filaments? All white doesn't come across on video and it's difficult to see the mechanism clearly.
i like white but i hear you
I use a lot of white filament, myself, but it doesn't come across on video very well. Try printing the gears, etc in different colors that contrast with each other. They will show up better on video and make it easier to see what you are doing.
Before I went back to school for my electronics degree, I was a graphic artist so I might be a little too aware of things like this. 😊
But I love your content. I do miss your lab, though.
Awesome!! Love it! Please show it working in the wind when you actually get some.
Will do!
and what about rotors turning in opposite direction - one turns rotor and other turns stator which is connected through slip ring contacts.
that would increase RPM on alternator.
Why not adapt the angle of attack on the two rotors differently to accomodate to the power loss. Not sure if it would be easy to measure if the angle "is good" then
How about using spring loaded tilting blades on the leading turbine?
if the difference causes drag, the blades tilt and pass more wind.
it's an idea mate - go for ir
Ever consider counter rotating turbines in which one rotates the magnets and the other rotates the coils effectivly doubling the speed between them?
rotating coils also means adding brushes for the electricity generated which means added complexity, more maintenance and a lot of energy loss.
Yes I made a video on it
Very nice Rob.
cheers mate
What about an ofset of the two rotors ? Not sure which way the pair would best rotate but im thinking of how migrating birds save energy by slipstreaming. Could this be worth doing, i dont know?
slip streaming does give an advantage -I believe it was the inspiration for this kind of wind turbine
Interesting....i could do with one of these on my little sail boat
that would be cool - did you like the sailing reference?
Suggest, add a Benbini on-line.
Use both sides of Coil, setting one side North-pole and South pole aligned, add pick-up coil to receive from magnet wheels, or D.C. Gene as Bearing for mag wheel and Gene simultaneously.
"LIDMOTOR" CHAN has build vids on these, uses one on his Sail boat actually.
@@ThinkingandTinkering I was thinking of it before you said it!
@@ben1895 lol - awesome!
Would counter rotating props be more efficient?
Been traveling for the past couple of months, finally begin printing the parts for your portable generator, decide to switch to PETG from PLE + because of it's superior durability, spend the next two days of fail, coming to the conclusion I'm a nube who forgot his KISS principle, switch back to PLE +, because that works and I'm making a prototype that I will no doubt muck up as a first go, print one of the gears successfully, look out the window, there's no wind, and decide to see what Robert is up to...I'm beginning to feel a bit like Dorian Gray's portrait.
wow - where have you been to and di you enjoy it?
@@ThinkingandTinkering Short version, Northern California to the coast, Southern Cal, to Palm Strings, to Tuscon, to Utah, to Nevada, to SF, to San Diego, there and back again. The highlight was drowning my sorrows at the absence of pubs and pints in the local wine bar. Sitting next to an retired electrician who thought I was quite mad for building a generator with a 3d printer and winding my own coil - serpentine, thank you very much, we bonded over my ignorance, enthusiasm, and tipped a glass to you.
Dear Robert, I got a 3foot toy turbine for my birthday. I got it working today. It changes two aa batteries.. 😊❤
Happy birthday! lol and that is cool!
You can run a, Joule Theaf/Joule ringer.
If the lights go out, in a Storm at least you got Light 😮... Dial it in charge cell phone... Real small Sand battery to Stirling cycle gene😅😅
You can quite easily run a 240v 1 watt led bulb very brightly with a hv stepup transformer and your 2x aa 1.2v batteries so great bit of free energy when the wind is blowing 👍
@@johnwynne-qx6br Ever make a Joule Ringer/TheaF inverter?
Transistor, Resistor, Bi-filar Coil, Either Cored or coreless, Toroid, Rod or Pancake works. Old speaker wire, Romex for Home even thin Bi-filar from a broken earphones.
These tiny inverter's are pretty great, 2n2222, 2n3907, 2n3055, 2n7401 almost all transistor's work. 2n3055 can handle Big coil though. using these I take a Solar lamp thing for yard, replace the bulb with inverter and buld on inverter, getting twice the light and run time as before. Put on window sill, makes a automatic light. Inverter is great emergancy thing.. On my channel I show diagram...
What about making a hydraulic fluid differential.
To produce electrical power and heat ?
It would be self lubricating at the very least and with proper design it could possibly charge a battery and heat a home simultaneously.
go for it
Too bad it wasn't windy that week.
I like the idea too. 👍💪✌
oh i will get it in the wind mate lol
@@ThinkingandTinkering I hope you make a video of it! Thanks Robert for your engagement in teaching and looking outside the box.
Could a bigger blade at the rear spin at the same speed as the front - sort of like a compound steam engine?
I believe it could
spring mass damper analogue is inductance capacitance resistance there should be an electromagnetic equivalent to a differential irrespective two generators seem to go on the shaft line by the looks given physical distance to prevent or limit somehow interacting electromagnetism and each suitably sized equally a differential is perhaps as good if not better in some or all respects the blades however are another problem much in the way it is as they pass the tower (resonance vibration condition)
I am not suggesting you use two generators mate - but you are right there are issues - there are always issues
Mars helicopter Ingenuity also used double propellors
Actually you don't need any gears. You can make coils spinning on first rotor and magnets spinning on the opposite rotor gaining much higher combined speed.
That was my first thought
cheers mate
Or we do a better generator! /Mikael PS Thanks for a good film❤❣DS.
cheers mate - a better generator is always a goo didea
The blades can turn at the same speed but different power.
cheers
Fun mechanics but I'd like to see someone test a contra-rotating wind turbine where the 'stator' actually moves, but in the opposite direction to the rotor. Blades need to be oppositely angled. the rotating 'stator' has the windings and brushes while the rotor has permanent magnets. I'd just like to see if it produces more power, or if the attraction between the stator and rotor poles slows each blade down to cancel out any gains or makes it worse than a normal turbine. It's even worse for birds but should be quieter.
why don't you design one mate?
@@ThinkingandTinkering .. lack of time and skills... The only 3D CAD package I've managed to master enough is Wings3D which is not parametric so no use for making real models. Fun, easy to learn and powerful in its own way, but old now. Great for designing round things like turbines, just not printing them. Attaching it to the shaft is probably the sticking point, and housing bearings.
I am sorry mate but that's definitely a poor reason. I did this in tinkercad which took me about 5 minutes to learn.
@@ThinkingandTinkering .. No way, that's some online megacorporate thing so two reasons I'd never use it.. I'll learn FreeCAD at some point as its offline and free, open source.. Not for this, but for a more interesting 'piston turbine' ICE + heat engine combo that's already wasted too much of my time, but good enough to make patent drawings. No way would I put a design I want to patent on some online corporate platform. They probably automatically own everybody's designs!!?!
Nice one Rob, one of these days I might be able to afford a 3D printer.
doesn't matter if you use a 3d printer or not - the same principles apply
It is possible, if you have a public library accessible to you, that they have 3D printers available for a nominal fee. I've seen some that charge something like 6 cents per gram of filament. You can forego the cost of buying the printer or full spool of filament yourself.
@@rafalklepinski7372 that is an excellent suggestion mate
@@rafalklepinski7372 I live in South Africa, so no chance of that.
@@staycurious8650 I wouldn't assume this is impossible. 3D printers have been around for so many years and some older models are so inexpensive it's quite possible you may find a resource like this. If you're near one of the more populous cities like Cape Town there must be some place, or at least someone who would "rent" their printer for a nominal cost. It is after all a way for them to make money with their printer so they wouldn't be secretive about this. If you take this a step further YOU could be the one offering a service like this to others, end up paying for that printer with money from people looking to print something.
Can you have a generator where one turbine turns the rotor and the other one turns the magnets?
How about a Tesla fluid pump to increase airflow and pressure directly off a bridge or road? Let cars move the air, or water underneath a bridge.
i qmnot sure how that could be made in a size big enough mate?
No counter-rotating blades?
nope
Then a whole generation of testing those eliptical oval props ...lol. Ducted vs unducted. Content for months and months
yep lol
Given the cost of the tower for a wind turbine i could see this being a real savings.
cheers mate
I'm not saying it's not accurate, but how come I have never seen one? I live in Sweden and I think we have a great deal of wind turbines. Companies are usually very greedy, so how come it isn't anywhere here.
I have no idea - quite a few in China apperently
Initially, I believed one turbine would rotate the magnets and the other would turn the coils... in different directions of course.
Its good idee.
Why not print it on the big ellegoo.
Ypu have one
Just use the bigg ellegoo they send you.
Then make it in pet.g.
Then Just print the balbearings.
In abs.
It wil meet the wether.
Whit no problems.
And its big.
You can also use superglu to wipe the whole thing down.
others don't so they couldn't repeat and experiment themselves
legend!
cheers mate
I had it in my head that they were supposed to be counter rotating instead of rotating the same way. Is there an advantage to one or the other?
in this arrengement i think it would be a disadvatage in the original arrangement i would think it would be an advantage
Why is it that people can't wrap their head around the fact that its called rapid PROTOTYPING, not rapid end consumer production?
I know! right! - it astonishes me lol
impeller type infront of a tube .. tube leads to fan ?
i don't understand mate can you expand?
@@ThinkingandTinkering I am wondering if an impeller shaped fan / centrifugal fan sitting in a ' sleeve ' shaped just right for air flow to increase around it and then flow through a small tube behind the centrifugal fan leading to another propeller type fan could generate more energy . or energy at all . haha . Have you seen the drones that fly using centrifugal fans ?
i think it has to much moving parts that makes it incredible to maintaince. but move forward and lets learn ;)
differentials are singularly the most common mechanism with around 200 years of research behind them and are perhaps one of the most fault free mechnaisms
Could just add more vanes to a single rotor, increase the speed for torque with pulleys. Good theory like triple expansion engine but overly complex.
no more vanes ona single rotor doesn't compare - have a read at the research mate
Smart 😀
cheers mate
Same design as the Eaton TrueTrac differential.
well if that is the case Eaton are just using a spur gear differential and calling it true trac - I didn't design the differential mate - i just modeled it
@@ThinkingandTinkering Just mentioning it has a similar action to something car guys might know. I wish I had models like that as a youngster. Cool video, thank you!
As far as making it last. Super glue.
Great point!
I see a problem with your design. Not a serious one at this small prototype scale, but it's going to come to bite you when you scale up. Every time the down-wind blade passes by the shaft, it's going to briefly dip into the wake of the shaft and experience a momentary reduction in force upon it. That is going to make the blade flex slightly every rotation, which is going to 1. Seriously reduce blade life and 2. Make lots of noise. This is why all rotating HAWTs place the blades in front of the shaft.
not all mate - check out the research on this kind of double rotor - it is fascinating
Where are the benefits?
read the research
Wind turbines can cause Havana syndrome
is that a real thing?
Cellior towers😮
First view, like, and comment?
My Lucky day!
lol - awesome
I think this twin rotor is dead in the water and not worth pursuing, It it was then we'd be using it.
If you study airflow then you'll realise that what comes out of the back of a turbine is a random mess of air and incapable of powering another one to any positive degree. It will actually be worse than that though and hinder the flow through the first one by having it's exiting energy reduced.
I hold you in such high regard that (and i've said it before) you are good enough to be on TV, but the one annoying thing is that you never see your projects through to the end. If you did that you'd be a much more powerful resource.
I wish I lived near you, i'd be popping round to team up and make some of these things and see if they work in reality!
it is being used
Umm - what's the point of putting the differential in?? You start with explaining the issue relating to the two sets of magnets, and then you proceed to create a dual turbine without the wiring OR magnets. What you end up with is a windmill, not a wind generator
umm indeed - do you not see that the take off shaft is where the generator will be? I don't want to be rude mate but you do need to think it through a little
😁
cheers mate
A two rotor differential turbine is a waste of material in my opinion. It is interesting though.
read a bit of the research - it might change your mind
@ThinkingandTinkering I don't doubt the effectiveness of the differential, but there is a good reason why they can't put wind turbines close together. I believe the materials could be better used on a bigger turbine or another turbine in another location.
More than one way to skin a cat. The differential could also be in torque instead of speed by adjusting blade pitch on a fixed axle.
@@TroyMackay absolutely mate lol
ah well we all have our ideas mate lol - I wasn't being rude by the way the research on dual rotors and their effectiveness set against cost is pretty interesting reading