I'm afraid I can't provide the original cad, but fortunately all the numbers you need to sketch it out for yourself are in the video! See 0:32, 1:01, 1:04, and 1:09 - pause the video so you can review the numbers. Truthfully just sketching it out on paper is probably more useful for demonstrating how it works than having the cad in hand. If you need help with understanding velocity diagrams, you might refer to this link: www.tec-science.com/mechanical-power-transmission/planetary-gear/willis-equation-for-planetary-gears/ If you have questions or wish to discuss it further, please shoot me an e-mail at sstrinka@gmail.com
Unfortunately, this does not work as the author states. There are two possible setups: One where the stacked planet gears are separate from each other and so can turn at different rates, and one where the stacked planet gears can be considered solid pieces. It is unclear which the author intends, but neither give you a 3600:1 ratio. If the stacked planet gears are free to rate at different rates, the top (yellow) gearbox basically freewheels: You can grab it and stop it since it transmits no power because it would permit the planet gears to run backwards. On the other hand, if the two stacked planet gears are one solid piece, the yellow part will turn at the speed of the black part (since it is already sitting on it, turning at its speed) plus the speed of the yellow part by itself. Essentially, the speed will double, being off from 2X by just the tiny fraction of a difference between the speeds. The only way you get the speed of the black gearbox to essentially cancel out the speed of the yellow gearbox, so that you can get a sum close to 0 (which is basically what a ratio of 3600:1 is) is if the yellow ring and black ring are turning in opposite directions. Then the speed becomes rpm(black) - rpm(yellow). But, they do not turn in opposite directions, they turn in the same direction.
@@jim2024now Hi Jim, thanks for commenting! It actually does work as described in the video. I have prototyped this design and it does produce the promises 3600 speed reduction with accompanying torque increase (minus inefficiencies). I suppose I could post a video of the prototype but the motor runs too fast to see the internal gears move with any clarity. I provided the math that demonstrates it in the video - I would recommend reviewing it, although I noticed the font colors were difficult to read, my apologies. All of the equations were derived from the velocity diagram for this gear arrangement. The stacked planetary gears are one unit, they are fixed to rotate together and must be in order for this reduction to work properly.
@@sstrinka Is there a way we can chat elsewhere about this? I'd love to get the details, but I'd rather not publicly post my email address. I apologize for being wrong about your device, but assuming that it really does work, I do not understand why this isn't EVERYWHERE. You are getting as much reduction in 2 stages as a typical stacked-planetary drive gets in 5 stages (or more). I suppose there must be a lot of force somewhere that might tend to sheer gear teeth off, but given that you can make them twice as thick in the same space since you only have 2 stages, and you could potentially change it to a 4-5 planet gear design instead of just 3, further increasing the contact area, I find this quite an important advance in high gear ratios.
@@jim2024now I appreciate the apology, but it's not necessary. I'm glad it was an earnest misunderstanding and not someone trolling 🙂. You can shoot me an email at sstrinka@gmail.com if you have anything you'd like to further discuss. This type of design is used in a few applications that I know of, I think it not more widely used because the gear teeth can't take the torque multiplication at high loads and finding the correct number of teeth that mesh correctly is actually rather complicated. I'd love to go more in depth with you about it.
getting serious civ4 vibes from music. Also, why does not this video have 2M views?
Thank you for the kind words! Stay tuned, I have some new designs in the works 🙂
I'm a little skeptical of this reduction in just 2 stages...would it be possible to get the CAD model? I'd love to take a closer look at it
I'm afraid I can't provide the original cad, but fortunately all the numbers you need to sketch it out for yourself are in the video! See 0:32, 1:01, 1:04, and 1:09 - pause the video so you can review the numbers. Truthfully just sketching it out on paper is probably more useful for demonstrating how it works than having the cad in hand. If you need help with understanding velocity diagrams, you might refer to this link: www.tec-science.com/mechanical-power-transmission/planetary-gear/willis-equation-for-planetary-gears/
If you have questions or wish to discuss it further, please shoot me an e-mail at sstrinka@gmail.com
Unfortunately, this does not work as the author states. There are two possible setups: One where the stacked planet gears are separate from each other and so can turn at different rates, and one where the stacked planet gears can be considered solid pieces. It is unclear which the author intends, but neither give you a 3600:1 ratio.
If the stacked planet gears are free to rate at different rates, the top (yellow) gearbox basically freewheels: You can grab it and stop it since it transmits no power because it would permit the planet gears to run backwards.
On the other hand, if the two stacked planet gears are one solid piece, the yellow part will turn at the speed of the black part (since it is already sitting on it, turning at its speed) plus the speed of the yellow part by itself. Essentially, the speed will double, being off from 2X by just the tiny fraction of a difference between the speeds.
The only way you get the speed of the black gearbox to essentially cancel out the speed of the yellow gearbox, so that you can get a sum close to 0 (which is basically what a ratio of 3600:1 is) is if the yellow ring and black ring are turning in opposite directions. Then the speed becomes rpm(black) - rpm(yellow). But, they do not turn in opposite directions, they turn in the same direction.
@@jim2024now Hi Jim, thanks for commenting! It actually does work as described in the video. I have prototyped this design and it does produce the promises 3600 speed reduction with accompanying torque increase (minus inefficiencies). I suppose I could post a video of the prototype but the motor runs too fast to see the internal gears move with any clarity. I provided the math that demonstrates it in the video - I would recommend reviewing it, although I noticed the font colors were difficult to read, my apologies. All of the equations were derived from the velocity diagram for this gear arrangement. The stacked planetary gears are one unit, they are fixed to rotate together and must be in order for this reduction to work properly.
@@sstrinka Is there a way we can chat elsewhere about this? I'd love to get the details, but I'd rather not publicly post my email address. I apologize for being wrong about your device, but assuming that it really does work, I do not understand why this isn't EVERYWHERE. You are getting as much reduction in 2 stages as a typical stacked-planetary drive gets in 5 stages (or more). I suppose there must be a lot of force somewhere that might tend to sheer gear teeth off, but given that you can make them twice as thick in the same space since you only have 2 stages, and you could potentially change it to a 4-5 planet gear design instead of just 3, further increasing the contact area, I find this quite an important advance in high gear ratios.
@@jim2024now I appreciate the apology, but it's not necessary. I'm glad it was an earnest misunderstanding and not someone trolling 🙂. You can shoot me an email at sstrinka@gmail.com if you have anything you'd like to further discuss. This type of design is used in a few applications that I know of, I think it not more widely used because the gear teeth can't take the torque multiplication at high loads and finding the correct number of teeth that mesh correctly is actually rather complicated. I'd love to go more in depth with you about it.