Russ Huber Posted March 19, 2023 Share Posted March 19, 2023 1 hour ago, Bill Dunlap said: The problem with those motors from Aliexpress is that the slowest one spins at over 6k rpm. eek. I'm not having something that spins that fast in my house. Now, if they are permanent magnet, brushed DC motors, they may respond well to a resistance coil for speed control. So, maybe... If someone could print up a couple of toroidal blades in brass around 8 inches, I'd be all in. I need one in CW and one in CCW. Cheers, Bill I wonder how well the motor would perform on reduced voltage, rather than resistance? Quote Link to comment Share on other sites More sharing options...
Bill Dunlap Posted March 19, 2023 Author Share Posted March 19, 2023 Something is in the works. Stay tuned to this bat channel. Quote Link to comment Share on other sites More sharing options...
Bill Dunlap Posted March 27, 2023 Author Share Posted March 27, 2023 Here's a short video of a very simple gear train that gets the contra-rotating job done nicely, but will need perfecting in order to be usable. But it does work well and now I know how to do it. 1 Quote Link to comment Share on other sites More sharing options...
Louis Luu Posted March 27, 2023 Share Posted March 27, 2023 2 minutes ago, Bill Dunlap said: Here's a short video of a very simple gear train that gets the contra-rotating job done nicely, but will need perfecting in order to be usable. But it does work well and now I know how to do it. Nylon gear....very good idea. Now, how do you get the extended shaft to extend so that there is two shafts turning opposite? Quote Link to comment Share on other sites More sharing options...
Bill Dunlap Posted March 27, 2023 Author Share Posted March 27, 2023 The motor I had in my stash had a modified shaft, turned down to .187 and shortened. It originally was threaded on the end. It got replaced because for some reason I haven't figured out it won't rotate in the CCW direction, only CW. It's good for mock-ups.... Cheers, Bill Quote Link to comment Share on other sites More sharing options...
Russ Huber Posted March 27, 2023 Share Posted March 27, 2023 Not sure if this concept will help. I watched it briefly, but no bevel gears involved I am not mistaken. Quote Link to comment Share on other sites More sharing options...
Bobby Gaines Posted March 27, 2023 Share Posted March 27, 2023 On 3/19/2023 at 10:33 AM, Russ Huber said: Hey Bobby, why not order one of those mighty mouse DC contra-rotating motors and give Bill some competition? If you do, I bet there will be some bright brass involved. 🙂 Russ some of the Stuff Bill does is Major league I still training camp. Quote Link to comment Share on other sites More sharing options...
Russ Huber Posted March 27, 2023 Share Posted March 27, 2023 19 minutes ago, Bobby Gaines said: Russ some of the Stuff Bill does is Major league I still training camp. Never panic. You can make brass shine, and make things spin 360 degrees. You're nipping at his heels. Trust me, Bill feels the pressure. Quote Link to comment Share on other sites More sharing options...
Bill Dunlap Posted March 27, 2023 Author Share Posted March 27, 2023 Russ, I think that one uses two motors. That's CHEATING! Quote Link to comment Share on other sites More sharing options...
Russ Huber Posted March 27, 2023 Share Posted March 27, 2023 (edited) 12 minutes ago, Bill Dunlap said: Russ, I think that one uses two motors. That's CHEATING! True, two motors. I did not watch it closely, but I don't recall the use of bevel gears. Not sure how he engineered that? Just posted the video to help. Eliminating the bevel gears is better. You had better hurry; Bobby Gaines has quit his day job and is on it. Edited March 27, 2023 by Russ Huber Quote Link to comment Share on other sites More sharing options...
Bill Dunlap Posted April 24, 2023 Author Share Posted April 24, 2023 I did a little more research into the toroidal blade designs and was astonished at the rapid development and innovation coming in any and all designs that incorporate any form of propeller. I even found a proposal for a ceiling fan using this design. And now, there are two, three, four, six and multiple toroid blades, many of which are available as inexpensive downloads for 3D printing. No one yet has published any design or even any interest in developing contra rotating toroid bladed applications, whether in boat, drone or fan types. The problem I see is that this requires one blade for clockwise rotation and another for counter clockwise rotation, necessitating two separate programs. I've been looking into fabricating my own and I think I may be able to do it by rolling a cylinder, probably in brass, and bologna cutting slices from it, first in one direction, then the other. Assembling the individual toroids will really be a challenge as any deviation from perfect alignment means untenable vibrations, tending to either multiply the problem in one case, but possibly cancelling in the best case. But, there will also be the possibility of inducing secondary imbalances, which can be minimized by placing the blades as close to each other as possible. Many different designs have emerged since MIT released their initial design earlier this year. Variations are numerous and the pace is breathtaking. I suspect that before long we will see experiments in jet engine turbine design that has the potential to revolutionize air travel The benefits of the design were initially only thought to be in low noise applications, but further experiments have shown that some designs can have enormous benefits in efficiency. Providing I have the time, money and energy to spare, I would like to develop further the idea of a dual toroidal bladed, contra rotating desk fan, in a classic, maybe Art Deco style. Ideal blade diameter would be 6-8 inches. Right now, I'm busy trying to enclose the gear train of the test model I have already assembled. Two main problems with it are the noise it generates, and lubrication, which is thrown off in all directions the instant the motor is started. More later, Cheers, Bill Quote Link to comment Share on other sites More sharing options...
Russ Huber Posted April 25, 2023 Share Posted April 25, 2023 (edited) 8 hours ago, Bill Dunlap said: I did a little more research into the toroidal blade designs and was astonished at the rapid development and innovation coming in any and all designs that incorporate any form of propeller. I even found a proposal for a ceiling fan using this design. And now, there are two, three, four, six and multiple toroid blades, many of which are available as inexpensive downloads for 3D printing. No one yet has published any design or even any interest in developing contra rotating toroid bladed applications, whether in boat, drone or fan types. The problem I see is that this requires one blade for clockwise rotation and another for counter clockwise rotation, necessitating two separate programs. I've been looking into fabricating my own and I think I may be able to do it by rolling a cylinder, probably in brass, and bologna cutting slices from it, first in one direction, then the other. Assembling the individual toroids will really be a challenge as any deviation from perfect alignment means untenable vibrations, tending to either multiply the problem in one case, but possibly cancelling in the best case. But, there will also be the possibility of inducing secondary imbalances, which can be minimized by placing the blades as close to each other as possible. Many different designs have emerged since MIT released their initial design earlier this year. Variations are numerous and the pace is breathtaking. I suspect that before long we will see experiments in jet engine turbine design that has the potential to revolutionize air travel The benefits of the design were initially only thought to be in low noise applications, but further experiments have shown that some designs can have enormous benefits in efficiency. Providing I have the time, money and energy to spare, I would like to develop further the idea of a dual toroidal bladed, contra rotating desk fan, in a classic, maybe Art Deco style. Ideal blade diameter would be 6-8 inches. Right now, I'm busy trying to enclose the gear train of the test model I have already assembled. Two main problems with it are the noise it generates, and lubrication, which is thrown off in all directions the instant the motor is started. More later, Cheers, Bill The only practical use of the dual propellers is with aviation, not fans. The only reason we looked into it is because it looks cool. 🙂 It would be as practical as Eck Dynamo's ----ming blade. The 12" ----ming blade survived on the market 2 fan motor seasons of 17 and 18. 16" DC models only in 19. AC and DC 16" models 1920+. Eck fan motors were off the map by 24-25. That is how successful the Eck ----ming blade was on the market. Fact Jack. Contra-rotating propellers have been found to be between 6% and 16% more efficient than normal propellers. However, they can be very noisy. Edited April 25, 2023 by Russ Huber Quote Link to comment Share on other sites More sharing options...
Bill Dunlap Posted April 25, 2023 Author Share Posted April 25, 2023 The idea behind the dual props is that you may expect the same or greater air flow, with a slower speed. Combining the toroidal blade with twin blades is an idea that it might hopefully reduce noise to an acceptable level. Both ideas have merit and the fact that I haven't seen anyone combine the two ideas is unusual to me. Therefore, I would like to try it. I'm almost done with enclosing the gear train. It is more complicated than it might appear on the surface. Cheers, Bill Quote Link to comment Share on other sites More sharing options...
Russ Huber Posted April 25, 2023 Share Posted April 25, 2023 19 minutes ago, Bill Dunlap said: Combining the toroidal blade with twin blades is an idea that it might hopefully reduce noise to an acceptable level. 1 Quote Link to comment Share on other sites More sharing options...
Russ Huber Posted April 25, 2023 Share Posted April 25, 2023 It's crazy how much stuff they have going on out there. I am almost certain I saw a single toroidal design fan blade patent 30s circa in past. Good luck! Providing I have the time, money and energy to spare, I would like to develop further the idea of a dual toroidal bladed, contra rotating desk fan, in a classic, maybe Art Deco style. Ideal blade diameter would be 6-8 inches. Right now, I'm busy trying to enclose the gear train of the test model I have already assembled. Two main problems with it are the noise it generates, and lubrication, which is thrown off in all directions the instant the motor is started. More later, Cheers, Bill Quote Link to comment Share on other sites More sharing options...
Bill Dunlap Posted April 25, 2023 Author Share Posted April 25, 2023 According to my info, this explanation of blade noise is off base. I think there are different approaches to noise reduction and the idea behind the quieter toroidal blade is the complete absence of blade tips. The thinking is that vortices are created at the blade tips which is the main source of noise. No blade tips, less noise. Now, I've also seen videos where the toroidal blades were actually louder than standard blades on drones which spin at 20k rpm or even higher. I believe that cavitation is responsible for the louder toroidal blade and at those speeds, it makes sense. At lower speeds cavitation won't be an issue at all. Another approach is to connect all the blade tips with a loop, thus eliminating the vortices at the blade tip. It's all very fascinating and lots of very clever minds are busy at work trying new things all the time. Quote Link to comment Share on other sites More sharing options...
Bill Dunlap Posted April 25, 2023 Author Share Posted April 25, 2023 When you think about the evolution of wing blade design, fan engineers were experimenting all the time with different shapes. When you look at aviation design, there is very little different in shape between the Wright brother's propeller and anything produced since. There is a strong tradition of experimentation of fan blade design right from the beginning of the humble house fan. Quote Link to comment Share on other sites More sharing options...
Terry Fisher Posted April 25, 2023 Share Posted April 25, 2023 Regarding the YouTube video that Russ posted above . . . . .This may explain why Eck used Ming blades on some of their fans. Especially the two blade different plane Ming design. Quote Link to comment Share on other sites More sharing options...
Louis Luu Posted April 26, 2023 Share Posted April 26, 2023 Bill....this is open source for generating the toroidal blade. Messing around with it right now. https://github.com/RaulBejarano/Ultimate-Toroidal-Propeller-Generator Quote Link to comment Share on other sites More sharing options...
Louis Luu Posted April 26, 2023 Share Posted April 26, 2023 Printed aluminum would be around $24. Quote Link to comment Share on other sites More sharing options...
Louis Luu Posted April 26, 2023 Share Posted April 26, 2023 Just tell me what parameters you want.... Quote Link to comment Share on other sites More sharing options...
Louis Luu Posted April 26, 2023 Share Posted April 26, 2023 Quote Link to comment Share on other sites More sharing options...
Louis Luu Posted April 26, 2023 Share Posted April 26, 2023 I think Bill is shooting for a Toroidal Contra Blade? Quote Link to comment Share on other sites More sharing options...
George Durbin Posted April 26, 2023 Share Posted April 26, 2023 (edited) Orville and Wilber Wright were the 1st even before our government to develop a way to measure blade efficiencies... And they were the 1st to be able to measure airplane lift efficiencies... Until they did it no one could do it... And they would not share it with the government... Boat manufacturers were guessing at what the best prop would be to thrust a boat forward... Very good reading or visit the museum in Kittyhawk! Edited April 26, 2023 by George Durbin Quote Link to comment Share on other sites More sharing options...
Louis Luu Posted April 26, 2023 Share Posted April 26, 2023 Post processing with smooth. Quote Link to comment Share on other sites More sharing options...
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