Not interference among planets Pi + 2 < (Si + Pi)*sin(180°/Npi) i is the i-th train (stage, if multiple); Npi is the number of planets of Stage i. You can check it with your drawings. Thanks!!!
Simplified equation for the gear ratio is (1 + (TR1 / TS1)) / (1 - (TP2 * TR1) / (TR2 * TP1)). I pulled that from an engineering journal article when i made the Java program, so I don't think you can reduce it further than that. [edited 12/8 to fix some messed up parentheses]
Awesome! This is just what I was looking for. I'm going to try and port your design to OpenSCAD (with attribution of course) for programmer folks like me who are not great at real CAD (Like F360)
I honestly would like to know more of the math involved. These gearboxes are obviously different than a planetary setup with a carrier, so I feel like the maths would also be different. Am I wrong? Either way, I have 2 main questions regarding these specific gear & gearbox designs: 1) How do you calculate the number of teeth needed for each gear to achieve some desired gear ratio? Is this possible/practical with this type of gearbox? 2) How do you calculate the gear ratio for each stage of the gearbox, as well as the final gear ratio of the entire gearbox, given some known number of teeth for each gear?
Love the videos - let me see if I can give back! You seem to have problems with pitch diameter with a non-zero helical angle. I believe the correct formula is : Pitch diameter = module * n_teeth/ cos (helical angle) So if helical angle is zero, the cos(0) is 1 and you get your standard "Pitch diameter = module * n_teeth", but if it's not, then this formula applies. Thanks again!
when rotating the planetary gears I found out that rotating it by 360 divide by the, number of teeth times 4 and multiply that by anywhere between 1 - 3
hey! I love your channel and I am really glad I stumbled upon it because I started to do a project where I needed a 1200:1 ratio (around this point) and had started doing it with just plain old fashion cogwheels but with the compound planetary it is so much better. I followed the eqs from this tutorial and found the perfect combination (S1:15, P1:19, R1: 53; S2:16, P2:20, R2: 56, which gives a ratio of 1205.8(6)). Now, you talk about torque transmission if you only had 2 modules (planetary 1 (P1)+planetary 2 (P2)) is not great, and you demonstrated it, but they were also somewhat short shafts, so now I have 2 designs, one where i have 4 modules, interleaved (P1 P2 P1 P2), but my output can only be from the last P2 as I need full 360° axial rotation. What did you find out by just having longer shafts on the input planetary? Because my second design is something like (P1 P1 P2) (I even made the input planetary base module 10% longer, so in total I only have something like 31% of the total length of the suns and planets for the second planetary. the problem is that Id like to keep everything really compact, and with this second design I save some space. Just wondering if you checked whether just having longer shafts on the input side tremendously help the output torque even in the case of a simple P1 P2 module. In the end, I would assume that what is important is actually just how long everything is, as this reduces the angular play room from end-to-end of the planets (i. e. the maximum allowed displacement is smaller if the shafts are really long, even for the P1 P2 combination). Of course that the case of interleaved modules enhances a lot the torque output specially for short shafts.
i've been curious about that for a while, it might be most important to get the proper length on just the first stage to hold the planets straigth, and then the second stage could be shorter. or course then you going to get questions about why the first stage needs so much more gear contact, but I think it would work.
Been waiting for another video. Thanks so much for taking all this time. I printed all the parts to the robotic arm, but just can't get my Prusa dialed in correctly to meet the tolerances in the STLs from Thingiverse. Hoping I can take your instructions and do them using OnShape.
Thanks. That's what I needed. I use Slic3r for a Prusa MK2. I knew I had slight tolerance problems, but since I did most of my own modeling, I could figure it out in the design phase for tolerance. Never took the time to get this dialed in. So in Slic3r it is XY compensation. And once again. Thanks for these videos. I just love your enthusiasm and you make some practical stuff!
A small tip: when you are drawing on camera, flip the image from top to bottom in post, so text and images are as you drew/written them from your perspective :)
I'm very tempted to patreon this, get the code, port it to C++, maybe multithread it, and see how fast it'd run then. Hmmmm… PS: And of course, not share it w/o prior approval. I'm just interested in checking *if* I can get it sped up significantly.
Haha it’s pretty fast with the java :) it actually takes longer to sort the file in excel than it does to make it. But come join the fellowship anyways!
I mainly thought about the target gear ratio 0 thing. It sounds like something that would benefit a lot from multithreading, although I'd have to check the specifics. Might even be possible to integrate this into a fusion 360 module (that could then simply generate the model), since python (which the Fusion API seems to build upon) interfaces somewhat okay with C++… Let's see tomorrow. Like I said, maybe I'll just join for the heck of it. ;)
Uhhh… ô.o Since when is C++ platform dependent? I and all my colleagues really must've done somthing wrong writing platform-independent C++ code for the past few years (not talking about specialized stuff like smart card chips or so here, but on these, your program almost certainly wouldn't run either).
From the point you build the executable. The source code can be written platform-independent but if you plan on actually running it, there's a build process. With the Java version all he has to do is have one executable for people to run on any operating system.
Dont know if this is of use but the software at 5:26 is javascript. In firefox i opened the javascript console and pointed to the number of planets slider and changed the max number of planets, similarly I change the max number of teeth, basically all parameters can be changed. The program runs and the animation and shows more planets and teeth just fine.
Interesting approach. I wrote a python program to calculate designs for this. But instead, I target a specific gear ratio, and brute force the required tooth counts. It's shocking how many ways there are to get a single specific ratio from a split ring gearbox.
If it matters, a good approximate for 50:1 with 4 planets and minimal tooth count would be S1=10, P1=14, R1=38, S2=10, P2=10, R2=30. This gives 50.4:1.
Do you think you could play around with cyclonic gear ratios some time? They seem like they could potentially provide good reliability at higher torques due to the forces being more distributed over the entire gear set. I don't know if the fact that the cyclonic gear doesn't use a secondary set of gears to turn the output will allow for more efficient ratios per single ring or if the amount of friction in the design from all the rounded parts sliding across each other will cause much efficiency loss or heat build up but I suspect that material choice and lubrication may play an important role. There is also an interesting side effect of the design since I'm not sure the gear can actually even slip until something inside structurally fails which suggests that while it might have a higher reliability and torque, it doesn't really give much warning that it's hit it's limit beyond maybe seizing up.
Get AvE to CNC you a steel one of these on his new 5 axis, see how much load it can handle. Do you do any load/torque calculations on these to optimize modulus/ratios for load? I'm designing a gearbox right now trying to optimize these factors.
Awesome Vid! How do you calculate the backlash in that program that you wrote? I've been learning how to mathematically Create Spur gears (Haven't gotten too far into helical cut gears....yet) But nothing that I've come across has yet to mention anything to do with backlash. The other Part that I would like to know is how to PROPERLY create the Ring gear. Cutting the ring gear out of a cylinder seems like cheating to me....There must be more math behind it to properly mesh it.
I guess what I really should be saying Is, I understand the clearance on the top and the bottom of the teeth for the ring gear. What I would like to know is, the Curvature of the tooth, Is it Mathmatically correct to mesh to an external gear? I never went to engineering school so I might be out to lunch on my question, Maybe the curvature of the internal tooth IS an exact replica of the External tooth. Just trying to figure that part out.
Hi, @Gear Down For What? I was just wondering about a part in the equation for checking if the gears are at perfect intervals. Is Teeth_Planets*2 the number of one planet's number of teeth or all of the planet's teeth combined? So if a planet had 10 teeth and I had 3 planets would the '(Teeth_Planets*2)' of the equation look like this?: Teeth_Sun + (30*2) = Teeth_Ring_Gear. That's my guess. I've tested it too and it seems to be correct.
So I designed a regular planetary gear set, just to test out if it would work, and when I put the internal ring on, I have to stretch it out with that little cut. Teeth: Sun: 10 Planet gears: 10 Ring gear: 30 Im using 4 planet gears. So...After I stretch the ring gear out to put in the sun and planet gears, the ring gear stays in that shape with a much bigger cut. The cut used to be a small 1mm cut, and now it's a 8mm cut. Any suggestions?
Nvm. I figured it out by looking at your 50:1 compound planetary gear video. Someone had same problem. The fix for me was making a horizontal expansion by -0.15 because my prints were off by .3mm. I did the 20mm x 20mm x 20mm calibration cube, and found out it was 20.3 mm on the sides. Hope this helps with anyone else having this problem.
So is it possible to do the opposite of this, a planetary gear box that has a 1:1, basically just spins the outer ring in the opposite direction but at the same ratio as the sun? Also why a bevel instead of straight teeth, doesnt a beveled tooth cause a axial push on the gear (I did see that you pair opposites toward the end)? Sorry is any of this is addressed in the video, I skipped around a little.
19:21 this is wrong. what good will it do to ONLY pull out that 1 surface? you will still have the same low/near non existing clearance on the actual sides that matter. the contact sides. you are basicly doing nothing at all like that. just making things even harder to print (smaller detail/sharper corners)
Please Please Please STOP doing playing in fast forward, and also frame skips/jumps. I am still learning Fusion 360, and slow down just a pinch when in the menus. I’m about to just give up on gears and use really stiff hard rubber cylinders that squeeze together. My motor will be powerful enough anyway to force through the tension, does that sound like a bad idea.? Can you help me make what I’m wanting to make?
Wow, and I was about to watch porn... but then I couldn't resist the shape and color of gears and planetary gear excitment and they got my full attention, I will watch again and again, there are many things to be invented yet on planetary gears.
Is there a reason why Stages 1 and 2 should have different teeth and module? Or can I just use the same module and teeth for ease of construction if I don't need to get a very specific ratio? Do 3D printed gears work, if the number of teeth is such, that there is a chance of undercut? I seem to remember, that because of undercut, you shouldn't use less than about 13-17 teeth. Not trying to be a smartass - I just want to better understand gears!
@@GearDownForWhat Thanks for the swift answer and in general for your awesome videos! I just saw, that the information about undercut is in the video at 15:55 - no idea how I missed it.. I must have gotten something wrong with your equation for the gear ratio, because I still get a reasonable ratio with same modules and teeth for both stages. I'm just going to outsource my calculations to mathcad to reduce such errors :D
Not interference among planets Pi + 2 < (Si + Pi)*sin(180°/Npi) i is the i-th train (stage, if multiple); Npi is the number of planets of Stage i. You can check it with your drawings. Thanks!!!
Anyway you can do high ratio with a worm gear? I need to transfer motor to an axel.
2:38 I stopped the video and googled "ainpow". After like 10 minutes or so I returned just to find out that you wrote "module" upside down :O
Thank you very much! You saved me.
Just became a patron. No BS...just learned more from this video than I did in my senior year in high school. 👍🏻
Awesome! I’m glad you appreciated it! I spent a lot of time making it!
One of the best youtube videos Ive seen in ages. Motivational. Thank you
Simplified equation for the gear ratio is (1 + (TR1 / TS1)) / (1 - (TP2 * TR1) / (TR2 * TP1)). I pulled that from an engineering journal article when i made the Java program, so I don't think you can reduce it further than that. [edited 12/8 to fix some messed up parentheses]
Thanks for sharing
would you happen to still have the source of this article?
Awesome! This is just what I was looking for. I'm going to try and port your design to OpenSCAD (with attribution of course) for programmer folks like me who are not great at real CAD (Like F360)
Did this happen? I definitely prefer OpenSCAD to Fusion 360. Let me know if you want help.
planetarygenerator.mateuszdrwal is newer and in javascript for anyone who wants to do this faster
Great job! Great job! Great job! Thanks
I honestly would like to know more of the math involved. These gearboxes are obviously different than a planetary setup with a carrier, so I feel like the maths would also be different. Am I wrong? Either way, I have 2 main questions regarding these specific gear & gearbox designs:
1) How do you calculate the number of teeth needed for each gear to achieve some desired gear ratio? Is this possible/practical with this type of gearbox?
2) How do you calculate the gear ratio for each stage of the gearbox, as well as the final gear ratio of the entire gearbox, given some known number of teeth for each gear?
Thanks a lot for the tutorial 👍😃
I’d appreciate it if you at the beginning of the video mention that your content is paid content and without payment the video doesn’t make sense
Very Very good method !
Man thanks a lot, i was looking for a guide to do this kind of stuff without finfing anything till i found your channel.
Man! You are a hero. Love this video so much
The planet gears have to be rotated 180/ to mesh in fusion
Love the videos - let me see if I can give back! You seem to have problems with pitch diameter with a non-zero helical angle. I believe the correct formula is : Pitch diameter = module * n_teeth/ cos (helical angle)
So if helical angle is zero, the cos(0) is 1 and you get your standard "Pitch diameter = module * n_teeth", but if it's not, then this formula applies.
Thanks again!
To rotate the planetary gears by the right amount just use the degrees per tooth quantity.
The loft operation @ 32:20 is causing the gearbox to bind up on some of the teeth. Remove the loft and just extrude a cylinder throughout the planets.
Thank's for posting! Can't wait to get to watch it.
when rotating the planetary gears I found out that rotating it by 360 divide by the, number of teeth times 4 and multiply that by anywhere between 1 - 3
amazing contents
wanna be friend?
hey! I love your channel and I am really glad I stumbled upon it because I started to do a project where I needed a 1200:1 ratio (around this point) and had started doing it with just plain old fashion cogwheels but with the compound planetary it is so much better.
I followed the eqs from this tutorial and found the perfect combination (S1:15, P1:19, R1: 53; S2:16, P2:20, R2: 56, which gives a ratio of 1205.8(6)).
Now, you talk about torque transmission if you only had 2 modules (planetary 1 (P1)+planetary 2 (P2)) is not great, and you demonstrated it, but they were also somewhat short shafts, so now I have 2 designs, one where i have 4 modules, interleaved (P1 P2 P1 P2), but my output can only be from the last P2 as I need full 360° axial rotation. What did you find out by just having longer shafts on the input planetary? Because my second design is something like (P1 P1 P2) (I even made the input planetary base module 10% longer, so in total I only have something like 31% of the total length of the suns and planets for the second planetary.
the problem is that Id like to keep everything really compact, and with this second design I save some space. Just wondering if you checked whether just having longer shafts on the input side tremendously help the output torque even in the case of a simple P1 P2 module.
In the end, I would assume that what is important is actually just how long everything is, as this reduces the angular play room from end-to-end of the planets (i. e. the maximum allowed displacement is smaller if the shafts are really long, even for the P1 P2 combination). Of course that the case of interleaved modules enhances a lot the torque output specially for short shafts.
i've been curious about that for a while, it might be most important to get the proper length on just the first stage to hold the planets straigth, and then the second stage could be shorter.
or course then you going to get questions about why the first stage needs so much more gear contact, but I think it would work.
Been waiting for another video. Thanks so much for taking all this time. I printed all the parts to the robotic arm, but just can't get my Prusa dialed in correctly to meet the tolerances in the STLs from Thingiverse. Hoping I can take your instructions and do them using OnShape.
using a negative horizontal expansion setting should fix your clearance issue :)
Thanks. That's what I needed. I use Slic3r for a Prusa MK2. I knew I had slight tolerance problems, but since I did most of my own modeling, I could figure it out in the design phase for tolerance. Never took the time to get this dialed in. So in Slic3r it is XY compensation. And once again. Thanks for these videos. I just love your enthusiasm and you make some practical stuff!
A small tip: when you are drawing on camera, flip the image from top to bottom in post, so text and images are as you drew/written them from your perspective :)
Your right! why didn't i think of that?
I'm very tempted to patreon this, get the code, port it to C++, maybe multithread it, and see how fast it'd run then. Hmmmm…
PS: And of course, not share it w/o prior approval. I'm just interested in checking *if* I can get it sped up significantly.
Haha it’s pretty fast with the java :) it actually takes longer to sort the file in excel than it does to make it.
But come join the fellowship anyways!
I mainly thought about the target gear ratio 0 thing. It sounds like something that would benefit a lot from multithreading, although I'd have to check the specifics. Might even be possible to integrate this into a fusion 360 module (that could then simply generate the model), since python (which the Fusion API seems to build upon) interfaces somewhat okay with C++… Let's see tomorrow. Like I said, maybe I'll just join for the heck of it. ;)
It's already multithreaded. Porting to C++ would just make it lose platform independence.
Uhhh… ô.o Since when is C++ platform dependent? I and all my colleagues really must've done somthing wrong writing platform-independent C++ code for the past few years (not talking about specialized stuff like smart card chips or so here, but on these, your program almost certainly wouldn't run either).
From the point you build the executable. The source code can be written platform-independent but if you plan on actually running it, there's a build process. With the Java version all he has to do is have one executable for people to run on any operating system.
Dont know if this is of use but the software at 5:26 is javascript. In firefox i opened the javascript console and pointed to the number of planets slider and changed the max number of planets, similarly I change the max number of teeth, basically all parameters can be changed. The program runs and the animation and shows more planets and teeth just fine.
Where is this located?
Interesting approach. I wrote a python program to calculate designs for this. But instead, I target a specific gear ratio, and brute force the required tooth counts. It's shocking how many ways there are to get a single specific ratio from a split ring gearbox.
If it matters, a good approximate for 50:1 with 4 planets and minimal tooth count would be S1=10, P1=14, R1=38, S2=10, P2=10, R2=30. This gives 50.4:1.
Do you think you could play around with cyclonic gear ratios some time? They seem like they could potentially provide good reliability at higher torques due to the forces being more distributed over the entire gear set.
I don't know if the fact that the cyclonic gear doesn't use a secondary set of gears to turn the output will allow for more efficient ratios per single ring or if the amount of friction in the design from all the rounded parts sliding across each other will cause much efficiency loss or heat build up but I suspect that material choice and lubrication may play an important role. There is also an interesting side effect of the design since I'm not sure the gear can actually even slip until something inside structurally fails which suggests that while it might have a higher reliability and torque, it doesn't really give much warning that it's hit it's limit beyond maybe seizing up.
Brilliant! I should find and see this video in 2017, too late for me.
bibliography please! im interested to learn more about gearbox
THANKS!!!
Get AvE to CNC you a steel one of these on his new 5 axis, see how much load it can handle. Do you do any load/torque calculations on these to optimize modulus/ratios for load? I'm designing a gearbox right now trying to optimize these factors.
Awesome Vid! How do you calculate the backlash in that program that you wrote? I've been learning how to mathematically Create Spur gears (Haven't gotten too far into helical cut gears....yet) But nothing that I've come across has yet to mention anything to do with backlash. The other Part that I would like to know is how to PROPERLY create the Ring gear. Cutting the ring gear out of a cylinder seems like cheating to me....There must be more math behind it to properly mesh it.
Yeah the video mentions how to adjust the ring gear to make it fit properly.
But you said it doesn't give you a "Perfect" Internal Gear? How WOULD you make it "Perfect"?
Wait until Ross K. makes an official update to the gear generator :)
I guess what I really should be saying Is, I understand the clearance on the top and the bottom of the teeth for the ring gear. What I would like to know is, the Curvature of the tooth, Is it Mathmatically correct to mesh to an external gear?
I never went to engineering school so I might be out to lunch on my question, Maybe the curvature of the internal tooth IS an exact replica of the External tooth. Just trying to figure that part out.
18:53 or you can just add negetive backlash. I do -0.3mm
Hi, @Gear Down For What? I was just wondering about a part in the equation for checking if the gears are at perfect intervals.
Is Teeth_Planets*2 the number of one planet's number of teeth or all of the planet's teeth combined?
So if a planet had 10 teeth and I had 3 planets would the '(Teeth_Planets*2)' of the equation look like this?: Teeth_Sun + (30*2) = Teeth_Ring_Gear. That's my guess. I've tested it too and it seems to be correct.
I think I meant just the number of teeth on one planet, not all of them.
@@GearDownForWhat Ah, thanks you for the reply. Appreciate the videos too. Very informative and helpful.
So I designed a regular planetary gear set, just to test out if it would work, and when I put the internal ring on, I have to stretch it out with that little cut. Teeth:
Sun: 10
Planet gears: 10
Ring gear: 30
Im using 4 planet gears. So...After I stretch the ring gear out to put in the sun and planet gears, the ring gear stays in that shape with a much bigger cut. The cut used to be a small 1mm cut, and now it's a 8mm cut. Any suggestions?
Nvm. I figured it out by looking at your 50:1 compound planetary gear video. Someone had same problem. The fix for me was making a horizontal expansion by -0.15 because my prints were off by .3mm. I did the 20mm x 20mm x 20mm calibration cube, and found out it was 20.3 mm on the sides. Hope this helps with anyone else having this problem.
Love this!
True story: first thing I ever 3D printed was a wall plate.
So is it possible to do the opposite of this, a planetary gear box that has a 1:1, basically just spins the outer ring in the opposite direction but at the same ratio as the sun?
Also why a bevel instead of straight teeth, doesnt a beveled tooth cause a axial push on the gear (I did see that you pair opposites toward the end)?
Sorry is any of this is addressed in the video, I skipped around a little.
Awww...Dude? is that an APPLE?
My heart just broke.
You keep saying 'module' but pointing to an 'ainpow' 🙂
19:21 this is wrong.
what good will it do to ONLY pull out that 1 surface? you will still have the same low/near non existing clearance on the actual sides that matter. the contact sides.
you are basicly doing nothing at all like that. just making things even harder to print (smaller detail/sharper corners)
ossum maan 🖒🖒🖒🖒🖒🖒🖒🖒🖒🖒🖒🖒🖒🖒🖒🖒🖒
14:00
Please Please Please STOP doing playing in fast forward, and also frame skips/jumps.
I am still learning Fusion 360, and slow down just a pinch when in the menus. I’m about to just give up on gears and use really stiff hard rubber cylinders that squeeze together. My motor will be powerful enough anyway to force through the tension, does that sound like a bad idea.? Can you help me make what I’m wanting to make?
YOU HAVE BECOME THE VERY THING YOU SWORE TO DESTROY
That no child left behind joke that only people 20+ will probably get.
Do u guys 3d print stuff for people, or where could I go to get something done?
hi
im wondering is the sun of stage 2 is stationary or not??
if not, is that two output in this case?
How did you learn all that ?
I want simpel over drivegear box low input high output
Wow, and I was about to watch porn... but then I couldn't resist the shape and color of gears and planetary gear excitment and they got my full attention, I will watch again and again, there are many things to be invented yet on planetary gears.
Is there a reason why Stages 1 and 2 should have different teeth and module? Or can I just use the same module and teeth for ease of construction if I don't need to get a very specific ratio?
Do 3D printed gears work, if the number of teeth is such, that there is a chance of undercut? I seem to remember, that because of undercut, you shouldn't use less than about 13-17 teeth.
Not trying to be a smartass - I just want to better understand gears!
If you use the same number of teeth, the ratio becomes infinite, and undercut can be a problem.
@@GearDownForWhat Thanks for the swift answer and in general for your awesome videos! I just saw, that the information about undercut is in the video at 15:55 - no idea how I missed it..
I must have gotten something wrong with your equation for the gear ratio, because I still get a reasonable ratio with same modules and teeth for both stages. I'm just going to outsource my calculations to mathcad to reduce such errors :D
Great video. Do you have an Instagram account? I want to do it by myself and 3d printed. I want to give you a shoutout
Nope, we’re a twitter species
Can I please buy one?
Can I buy that gear set from you?
Sir where i can buy this?????