How to model Planetary Gears; Requirements, Gear Ratios, Helical/Herringbone (Gears pt 5/7)
ฝัง
- เผยแพร่เมื่อ 14 พ.ค. 2024
- I show how to model a ring gear, how to set up planets, carrier and sun, joints and motion links, and making helical/herringbone sets. I'm using Fusion360, though it should work fine in other CAD software, and I 3D print the set to show you that it works.
Files: www.thingiverse.com/thing:465...
Playlist with all my gear tutorials: • All about gears
Further reading:
Mathematically perfect ring gears: khkgears.net/new/gear_knowled...
Willis equation for when all 3 gears move:
www.tec-science.com/mechanica...
Instagram: / creo_nova
Website: www.creonova.nl/
Timestamps:
0:00 Introduction
0:28 Modelling ring gear
1:47 Adding a regular gear
3:54 Setting up motion link
4:58 Examining interference between pinion and ring gear
7:43 Making ring gear with proper backlash and clearance
11:12 Checking meshing with new ring gear
11:58 Turning mechanism into planetary gearset
21:25 3D printed planetary gearset
22:02 Comparing planetary gearset to regular spur gear
22:53 What happens if you don't correct addendum/dedendum
23:32 Mathematical requirements for working gearset
28:08 Gear ratios in planetary gears
30:03 Making helical planetary gears
32:31 Making herringbone planetary gears
34:01 Warnings for helical/herringbone planetary gearsets
35:49 Outtro touching story - วิทยาศาสตร์และเทคโนโลยี
Been looking forward to this video for a while, I've saved it to my list of videos I need to watch when I've got a bit of free time from school. I've had several projects in mind that would make use of a Planetary Gearbox.
Nice to hear, let me know if anything's unclear after watching
Another amazing video on gear design. This is the most detailed and easy to understand video on planetary gear design i have come across so far. Great work Antalz !
Thanks a lot, I finally got the research and script ready for bevel gears. Hopefully I can crank that out somewhat soon.
Watched the whole series at once! Great material and I hope you continue to post these very informative and clear material. Greetings from Brazil!
Thanks a lot mate! Warm regards from the Netherlands
This is the second time that i watch this video & not missing a second ! the content in this channel is outstanding i hope that the community gets bigger
Thanks a lot! I'd love to see the community grow too, I think if I make more and better videos it can certainly happen. I haven't uploaded anything in a few weeks now unfortunately.
Yes i can confirm
Whoa..it's amazing how professional your materials are and how well You can cover given topic. I really appreciate your work, thank you and keep it going!
Thank you, and I'll keep going
I was making the model while watching, and at almost 5 mins in, my power got cut. I'm grateful you said we're gonna start from scratch again haha
Your tutorials are really some of the best out there. They're so much more practical than most other ones. I swear every tutorial says, "this is the gear tool, thanks for watching" but you actually show meshing gears together, joints, pitfalls, etc. It's amazing.
Thanks for that mate! And yeah that's why I started the series. The other thing I saw way too often is teeth being drawn by freehanding a spline.
I really appreciate your teaching style, all of my questions are answered! Take this sub :)
Thank you for sharing a top notch tutorial!
Hands down best gear content on YT!
Thanks mate! Nice nickname you got there!
Thank you for the way you clarify these complex issues. I'm a designer not an engineer. Your explanation of the principles and the step-by-step walkthrough in F360 allows me to do do more modeling before sending it off to the engineers for their review.
Great to hear, thanks for watching!
Loved the video it was very detailed and easy to follow
Thank you for the video. I have learned a lot about gears. Best regards from Germany!
Awesome content. Thank you for taking the time,& energy to make such informative videos.
No problem, thanks for watching
Great Job!!
It does not seem that long when you are watching it.
Thanks!!
Thanks a lot mate!
Thank you for a better teacher than my professors in the various Machine Design classes I took. Some of the best videos I've found on practically designing gears.
Thanks a lot mate, that's really encouraging to hear!
Thank you for creating such a great video! Even a fusion novice like me can follow along and create this amazing model.
Great to hear you were able to follow along, thanks for watching!
Your video was so helpful!!
Thanks from Italy!
Great to hear, thanks from the Netherlands
This video is amazing. Keep up the good work!
Thanks, and I will!
Great video, l learned a lot.
Thanks for sharing your knowledge.
Waiting for more videos.
Thanks a lot, I've been out of it for a while but I am ready to record the next bit about Raspberry Pi. Hopefully after that bevel gears.
This helped me with my university project. Thank you very much.
That's great to hear, thanks for letting me know, and thanks for watching
Hi!
First i wanted to tell, that your video series on constructing gears is absolutely amazing. I especially love the maths behind planetary and helical gears. Also the conditions to check if the planets will fit nicely after the circular pattern are really useful for me. I even derived a formula for Excel to calculate the rotation angle for each planet if there is no perfect fit:
=MOD((planet_number-1)*Ring_teeth_count;total_number_of_planets)*360(Planet_teeth_count*total_number_of_planets)
NOTE: depending on your number format settings the ";" may have to be replaced by "," and depending on language settings, the function MOD() may also have a different expression!
Planet_number=1 stands for the originally created planet gear which is used for the pattern (angles calculated by the formula only apply if 1st planet was rotated so that it fits, before applying the circular pattern), so for first planet the result will always be 0°. For the other planets, if the calculated values don't work, just turn them in opposite direction with the same value (just write the angle with negative sign)
I also think I have found another way to create the ring gear. I don't know if it is a better way, or even a valid method, because I'm not an expert regarding gears. I try to describe it in a way that you or someone else can recreate it and would appreciate if I could get some feedback. I will now describe my method for creating a ring gear with module 1, 50 teeth, pressure angle of 25 and 0.2mm backlash and root fillet:
1. use the Spur Gear tool an dial in the settings
2. activate the gear component and expand the steps on the timeline
3. delete the circular pattern, the root fillet and both extrude features, so that only the 3 sketches remain
4. turn sketch 2 and 3 visible, hide sketch 1
5. double click sketch 3 to edit it
6. draw a horizontal construction line that is long enough to bisect the single teeth on the right and make it coincident with the origin
7. construct a point and make it coincident with the horizontal line and with the circle in sketch 3 that has the pitch diameter
8. select all lines of the single gear tooth and copy, then deselect and paste
9. in the Move/Copy dialog use the free move option, click on "set pivot", select the constructed point and click done to set the pivot
10. now turn 180 degrees and click OK
11. now hide sketch 2, you don't need it any more and create a circle with the diameter of (pitch diameter + 2 * 1.25 * module), 52.5mm in this case
12. create a bigger circle depending on your needs and finish sketch
13. first extrude the whole ring to the desired height, then extrude the whole tooth to the same height and change operation to join instead of cut
14. now add the root fillet to the root of the tooth on both sides
15. use the circular pattern feature, select the extrude of tooth and the root fillet feature and make 50 copies with "identical" option
16. ring gear is ready with regularly shaped teeth, no more need for addendum/dedendum correction
I don't know if this is a better way than what you showed, because maybe ring gears should not have the same shape of teeth because of their inverted curvature, but I made one with zero backlash and animated it in fusion and it seemed to fit well. Also I have already printed some herringbone planetary gears (print in place) with 0.23 backlash with this method and they seem to work well.
I know that this is an old video, but I hope you still read comments :)
best regards,
Zoltán
Hi Zoltán, thanks for that Excel formula, that might be useful to some viewers. I haven't yet found the time to look into your modelling steps, but I saved them in a text file so I can look into that later. I do still read comments, but a bit belatedly as you can tell because life got a little busy.
Thanks for this, very in depth and helpful
No problem mate, thank you
Thanks for the video! Very informative and clear
Thanks mate!
very helpful tutorial.Thanks!!!!
Great video, thanks for sharing your knowledge!
But there is another way of assembling a herringbone planetary gearbox, that might be interesting: You could print the whole assembly right in place. Someone at my university did this a year ago and it worked really great!
Yeah that's certainly possible, and in previous parts I linked to the Emmett gear bearing which is exactly that. You run into assembly problems quite quickly though, when you want to connect the sun gear to a motor shaft, when you want to attach the planet carrier, and usually the planets will block you from putting screw into the faceplate of the motor as well. It's an amazing demonstration of some of the completely new capabilities of what a 3D printer can do, but I don't think in this context it's actually practical.
Yeah, I saw these gear bearings, but with a little bit higher tolerance I could imagine getting this to work as a planetary gearbox. Maybe I'll give it a try in combination with my master thesis :)
Really nice. You should do harmonic drives also, they are pretty interesting.
nice video, perfect work!
I was waiting this video, thanks mate
Thanks, sorry to keep you waiting a bit longer than anticipated
@@antalz don't worry, I know making a video is a lot of work, so it's appreciated
This is the master class that I never have.
Thanks so much, that's exactly why I make this video series.
Really useful video. My congratulations. I hope you make the "practical gearset" video. That could be really cool!
I'm currently setting up to get back into making videos, so perhaps that'll happen in the next few months. First I have to record that drybox video though, and I don't dare plan too much further ahead than that.
Great series, any chance of a followup coming showing how to model a worm gear and matching worm wheel?
There is a chance for sure, but I'm afraid it won't be soon. I have a few videos I want to make first for sure, and video production has been kinda slow again. I haven't yet found a solid method of modeling worm gears either. I did some experiments with sweeping a tooth profile along a coil, but I'm not sure if the result is accurate. They're also a difficult to print, so I'm trying to find a way around that too.
Really your lecture excellant on this subject thanque
I had posted a question about making a gear-reduction drive for a radio tuning capacitor. After watching this video, I think the planetary system could be utilized because the outer-ring gear could actually function as a tuning-knob. Also, the thought of stacking/cascading 2 planetary-sets is also interesting and hopefully would not be terrible on backlash; unless you have to include a lot of clearance just to get this many things to rotate without excessive force. Once again, thanks for the videos and the new microphone sounds fine...
Basically every gear-gear contact the force has to be transmitted through gives a bit of backlash, so using the minimum number of gears would be best probably. I think using a planetary with moving outer ring might be quite easy, though you'll need quite a bit of space for 8:1 ratio. The minimum number of teeth on a gear is a bit tricky, but when you have a pressure angle of 25 degrees you need 12 teeth minimum. You can go with a higher pressure angle so the minimum becomes lower, but high pressure angle is bad for backlash.
A lot depends on the space you have available, I would say with FDM you don't want to go below module 1 mm, which gives a minimum pitch diameter for the pinion of 12mm. If you have to go smaller then SLA is required I would say.
@@antalz Well thank you for getting back to me I really appreciate it. It’s probably impossible to make it as small as what I would like. Here is an example of what I’m looking for but it is all metal and they used to sell for about three dollars USD but as you can see they’re very expensive now:
www.amazon.com/Philmore-S38-Vernier-Control-Knob/dp/B00A9HHTCQ/ref=sr_1_6?dchild=1&keywords=Vernier+radio+dial&qid=1620920700&sr=8-6
Anyway, I do have use for gear assemblies for other projects and so thanks again for doing these videos and your reply!
Thanks, that was very well done.
Thank you, I think I can continue the series with bevel gears in 3 weeks or so.
Thanks! Very helpful
Excellent, thank you!
Thank you for your work
My pleasure, thank you for watching
Thanks this helped a lot
That was a very cool tutorial. I'll probably have to watch it a time or 2 more to get my head around the formulas, but it's given me a lot of ideas.
A couple of questions though; If you're making a planetary gear set out of metal, machining cost and time are factors as well as weight so 3 planet gears is probably optimil. For 3D printing, strength would be more of a concern so I'd think that 4 planet gears might be preferred or even increasing the size of the sun and going with 5 planets to spread the load a bit more.
Also, for a herringbone set, wouldn't it make more sense to have the ring gear split vertically? (same effect as not joining the 2 helical ring gears) You'd mesh the planet and sun gears, then push them into the lower ring gear. You'd then push the upper ring gear down onto the planet gears and it would twist into place. You'd have to add a flange with holes to the upper and lower ring gears, but once they're together you could just bolt them together.
This would also give you a mounting system for fixing the ring gear in place.
Or is there something I'm not considering about this method?
For the planets, no not if you're a home gamer. What you do is you take a long bit of roundstock, then you cut the gear teeth into that using a rotary divider. Let's say you cut 100 mm length of gear teeth. Then you can easily obtain 6 gears of 15 mm thickness out of that. The only extra work is that you have to part of more gears, but you don't need to do any more indexing/dividing.
It does make sense to split the herringbone into helicals, but it's very tricky to obtain perfect alignment, it's nearly impossible to have a perfect smooth transition between the two. That's why often there's just a bit of bare cylinder between the two, that's known as a split herringbone. I think that'd work just as well, it's just a smidge less compact.
Rather than split the ring gear as shown, to stretch it to allow assembly, couldn't you split it in the XY plane instead? So, where you mirrored it and selected 'Join', just don't join it. Then it becomes a pair of helical gears which do slide into mesh (I was paying attention in previous videos :D ) and the two halves could easily be screwed together after it's all meshed up.
That is possible, but it's critical and very difficult to accurately align the ends of the helical gears, so that the mechanism doesn't crash or interfere with the tips.
Great vídeo!
Great vid, Antal! Thanks much! I have a question about fixing initial spur gear's de-dendum though. At around 10:12 where you update the initial sketch's circle, you substituted 112 - (2 * 2) for the original ~107 diameter. How did you decide on that 112 value? Thanks in advance for the answer! :)
Ya know what... I bet it's the pitch diameter! 56 teeth w/ module 2.
Yeah that's it, you start from the pitch diameter and then the addendum is 1*m in both directions, the dedendum is 1.25*m. Not sure why I left this unanswered so long, sorry about that.
@@antalz , thx much for the confirmation! :)
Thank You for sharing this video, this is really helpful, i have been creating planetary gear system in Creo. This seems like very easy to model up planetary gear system. Which software did you use?
I'm using Fusion360 for this entire series. Creo should have a gear generator, and then most of the process should be similar.
Thanks for this video, Antalz. However, I have a problem modifying the spur gear to make the internal ring gear. I expanded the spur gear timeline and added the press-pull step to add the extra for the dedendum. I selected the face of the single tooth and made a 'New Offset' and it modified it OK. I next moved the timeline to the end and edited the circular pattern. It showed an outline of the teeth it would make and they were correct but when I clicked OK the circular pattern did not modify the teeth, they were the same as the original teeth except the modified tooth. Do you have any idea what I might be doing wrong or why this is happening? Is there some other settings in Fusion 360 I need to modify? I do have the latest version, thanks.
Did you select the press-pull feature on the timeline to also be patterned? So in the end it's a circular pattern of two features. Maybe the compute mode of the circular pattern matters too? I'm not sure what else might be the problem.
@@antalz Thanks! I couldn't seem to select the face that was pulled but forgot to press 'Ctrl' and select the face. Now I have the ring gear modeled!
@@daveschings828 Nice! Good luck with the rest, let me know if you run into any further issues
Awesome video! THank you
Thank you, thanks for watching
nice job mann
Thanks!
I have a question for the addendum why did you subtract (1*module) from the root diameter
Thanks for this video, it's very helpful. I follow your video and manage to get my first planetary gear. However, when I play a bit more, I noticed that gears Sun(20teeth) + 2xPlanet(20teeth)+Ring(60teeth) doesn't work when I am adding remaining two planets. Can't match angle to get proper alignment of planet gears with sun gear and ring gear.
That's because you didn't meet requirement 2 shown at 23:34. ring+sun is 80 teeth, and 80/3 is not an integer. 4 planets will work, if there is enough space, which you can either just try, or you can calculate it with requirement 3.
@@antalz Thanks once again. It's clear. Looking forward for a new videos. Good luck.
Great video, Thank you. Any chance of doing one for cycloidal gear drive?
Thanks for watching! There's a chance for sure, I'm hoping to get back into making videos at the beginning of next year.
Great content sir,
I am an Electrical engineering student, yet I am very interested in mechanical design.
Thanks mate, and that's good to hear. Always a good idea to keep a broad horizon.
Great demonstration!
I faced an issue though, my system did not retain the joints for the helical gears as they did it for yours at 33:11
When I animate the model, only the already-existing spur gears move and not the new helical ones!
Is there something I should take care of?
Make sure that when you're setting up the path and you're doing the sweep, that the corresponding spur gear component is active. The body you create must be inside of the old components that are jointed up, the bodies must not end up in the root component.
@@antalz Oh yes! I had been careless while switching between active components
Thanks a lot!!
I must say by your videos that you are a wonderful teacher
@@antalz We are actually working on Recumbent bicycles (which utilise epicyclic gears)
If possible, can you provide some help on that as well
@@sahil3104 Thanks for your kind words! For specific questions you can reach me at antal@creonova.nl, and I'll see if I can help.
@@antalz Sure!!!
Thank you for this amazing tutorial !
I tried to replicate it with module 2.1; 27t ring gear and a 9t gears . I changed the ring gear root diameter to 56.7-2*2.1, extended the teeth by 0.25*2.1 (the diameter is 61.95 after this), and added -0.3mm backlash. The planet gear center is 18.9mm from the center of the ring gear, 0.3mm backlash. I get an interference between the root of the internal gear and the straight profile of the planet gear.I have the bracket grounded if that matters. I can remove it by adding root fillet radius to the ring gear, but that seems like a workaround with unknown consequences to me. What could be causing this interference? I also tried with 36t and 12t and got the same result.
I suspect it's because 9 tooth gears fall well below the minimum. For 20 degree pressure angle, you need 17 teeth. For 25 degree pressure angle 12 teeth. Below those minima "undercut" is required, which Fusion360 does not model.
If you repeat the 12t model with 25 degree pressure angle it should work. I think you did the construction correctly in itself, though I can't be 100% sure from just a comment.
@@antalzThanks. I tried it with 9t first and 0.9 root radius on the ring gear and it worked.
hello sir antalz, sir about the 2nd requirement do I need to still achieve the Zr/Np and Zs/Np or just achieving the (Zr+Zs)/Np will be good enough?
Achieving just the last requirement is good enough, achieving both is only necesary for having the planets in phase, which is only useful in some very niche mechanisms. I don't think there's any real practical use to it.
@@antalz copycopy sir thank you
Hats off!
Thank you!
hello sir, i have a question about the 2nd condition Zr+Zs/Np, as long as the final result is whole number then it means that my planetary gear will work properly and equally spaced?
Yes that will ensure the planets are equally spaced. The third condition is also required, to ensure the planets have space between each other.
@@antalz thank you sir :D
@@antalz sir another question about the third condition equation, what is the numerator after the sine?
@@kennethpaulfajardo5402 Pi divided by the number of planets. So the planets start interfering with each other if you have too many of them, basically.
@@antalz copy sir, thank you
I am facing another issue here,
when I downloaded the model you made and opened it on my system, it worked flawlessly. I could drag the gears and the motions worked out perfectly (In the spur gears, helical gears and herrington gear models ). But when I created my model following the exact same steps as yours, I am able to drag the spur gears and the other joints work well.
But for the other cases, I am unable to drag the (planet) gears. Clicking on 'animate joint' works but it only animates the individual joint. Clicking on 'animate model' gives no result! (while it works on your model that I downloaded)
Would you please let me know what thing should I check?
Check that all the components, joints, and motion links I have in my file are in the same place in the tree as in your file. I suspect you're missing a motion link, or that one of your joints is inside one of the components, something like that.
@@antalz Thank you for your reply!
I checked it, my model-tree has exactly the same components as yours. Can it be related to my system's specifications? (I guess not)
@@sahil3104 Seems unlikely to be honest. Could you send the file to my email?
@@antalz I am amazed by your willingness to help.
I will send you my file right away
Thanks!!
Hello again. I had some extra queries which I have emailed you. Kindly give some guidance.
Thanks in advance!
I am getting a little lost around 15:30 after re-gorunding the components clicking and dragging does not work and when I form the final motion link there is no movement. any ideas?
You should have only one component grounded, a grounded component is completely stopped from moving. Besides that make sure you don't have contact sets enabled. I can take a closer look tonight
im not sure if something changed in fusion 360 but sweep -> twisted angle does not create the same "real" twisted shape by angle for different gear dimensions and the same twisted angles.
This has always been the case, and I covered this in video 3. The formula is [angle you should put into Fusion360] = (360*[length of the sweep path]*tan([helix angle you want])) / (module*[number of teeth]*PI). I hope that answers your question, I may have misunderstood it.
If there is 2 sun gears with 2 shafts ouputs. Rotateing in different directions with same speed. Can you do it?
I believe not, not if both suns are connected to the planets. Because if the planets spin in one direction, both suns must turn in the opposite direction.
@@antalz yes, I agree with you.
But in the case I am asking. Every sun gear is commented with planetary gear. Because it has 2 set of planetaries gear. However, the 2 set of planetaries gear are connected together.
Fusion doesn't let me add the press/pull offset to the circular pattern for the dedendum adjustments, any other way to do this?
If anyone is reading this and is also having the same problem what I did to solve it was to modify the gear tooth sketch itself and manually adjust the tooth profile, once you click finish sketch it will update the body and apply the new tooth profile with the dedendum added to all teeth
Could you perhaps create the presspull, and then create a pattern just of that presspull? Perhaps even do the presspull as a new body, then a circular pattern of bodies, then modify->combine? I haven't heard this problem before, did you change the pattern type to features first?
@@antalz I tried this as well, it seems that the offset face being used as a revolve feature is what fusion didn't like, i made sure that the revolve was set to features, I was able to get a good working model by modifying the sketch and then following the rest of your video, I've made a 3d print and the gears mesh correctly!
I had an issue here as well. At 09:45 in the video, I could not select the 2nd object, and when I chose 'Adjust,' Fusion said, "Too many pattern instances." If I lower the Quantity to 49, Fusion does not complain. At 50, it complains.
@@milehighslacker4196 Did you get it to work in the end using Liam's method?
Let me point out that your method of creating the ring gear doesn’t generate proper involute tooth profile but instead you get a profile that is an inverse of the involute gear profile.
This really doesn’t matter for printed plastic toy gears but in the real world the gears would wear out quickly due to excessive friction.
That sounds plausible, but the resulting shape is extremely close to what purpose-built gear generators make, to within a few microns for a module 2 gear, which is beyond the manufacturing accuracy or surface quality almost anyone can achieve.
ahm sir I notice that the final motion of the planetary gear is rotating 360 degrees and then back to 0 degree again, how can I rotate it continuously sir without getting it back to the initial position?
I believe you can not, at least not with animate joint. Maybe with a motion study, but I don't remember having luck with that either. If you animate joint on the planet carrier it works better than if you animate the joint for a planet.
nice..... could you explain how to make a planetry gear if I only have these data:
Make a multiplier gear x5, with three planets, the crown 25cm diameter
How I calculate the diameter, the center distance, etc??
I'm going to assume a few things. I assume the crown gear is the ring gear, and the ring gear is held stationary, and the input is the sun gear. If the pitch diameter of the ring is 25cm, that means the sun is 6.25 cm pitch diameter, and the planets are 9.375 cm, that follow from the gear ratio formula with a x5 ratio. You can compute the rest of the values you want quite easily, except for the module. On the one hand Ring+Sun must be a multiple of 5, and of 3, so Ring+Sun = 15, 30, 45, 60, 75, 90 etc. One choice is Ring = 72, Sun = 18, so planet = 27, for example. I can't find a solution where the module has a preferred value though. It does sound like a very strange gearset.
@@antalz thanks so much for reply. I saw in another video, if the planetary gear is multiplier and the input are the planets (sun is the output), the sun diameter has to be smaller than the planets diameter. And You are telling me the opposite.
Is that right what I'm saying??? please tell me if I'm wrong. Is there any significant diference if I Take the planets or the sun as an input???
@@gianbetos Not totally sure what you're saying. The gear ratios are at 28:30 in this video, and I do assume sun is input, planet carrier is output. If you do it the opposite way, you will get the opposite ratio. For my formulas, a result of 5 means 5x more torque, and 0.2x speed, some sources use the opposite convention. I use this convention because most gearsets in reality are speed-reducing torque-increasing gears.
@@antalz ahhhh, my wrong, "5x" I meant faster, I don't care torque for my aplication. So, I only invert the sun and planets diameter???
@@gianbetos For 5x faster you can use the numbers I gave, but use the planet carrier as input and sun as output
At 10:30, fusion 360 does not re-attach the teeth to the diameter. How can we go about doing this?
Edit: nevermind, I was able to redefine that sketch and set it inside the cylinder, which then ended up merging the two in the end. I tried a few things before that and couldn't make them one piece.
The only way I could reproduce this is by making the diameter of the first circle so small that there is a gap between the cylinder and the teeth. Fusion360 will never allow you to join 2 bodies if they are disjoint in space. I understand you've fixed it already, but I'm just trying to understand what's going on so it could help people in the future if they run into the same thing.
@@antalz for some reason, when I do the same calculation as you (diameter-2*2) it does shrink the diameter to be smaller than what the teeth reach. My original diameter is 96mm I think, and I have 50 teeth, but everything else is the same, if that helps.
@@hayatotenryuu9850 What module are you using for you gear, 2mm? In that case your inner diameter should be 96mm after modification. If I do it in my Fusion360 the diameter is 95.098 before I go in and modify it. Note that the modification should make the circle larger than it was before.
@@antalz I'll have to go back and look to make sure about all of the dimensions. I'll post a reply here with the specs I used in a little while.
@@antalz okay, so my original spur gear was 96mm in diameter, modulus of 2, same backlash as what you did, everything else the same as well, with 50 teeth. Then, like you went back and changed the diameter and edited the tooth, I did the same. I pulled the tooth 1mm, and then the cylinder diameter was (96-2*2).
You said it was supposed to get bigger from this operation? I don't know how large I want the hole to be for my application, so I was using (the original diameter - modulus *2). Obviously this was an example that you were doing, but I'm curious how you know what size you want the hole to be for your ring gear before making the other two gears in the system.
this could help me for multiply rpm on small windturbines ??? i need somehelp
You could use a planetary gearset, yes, but if you're inexperienced with gear assemblies I would recommend using a simple spur gear set like in video 1. I don't think a wind turbine absolutely requires a planetary.
@@antalz you are right dear.. i will try with spur gear.. thanks a lottt :)))
hello sir Antalz what is the recommended backlash value in gears also how can we determine what backlash value to use?
That depends entirely on how accurate your manufacturing process is. Speaking very roughly, if you have 0.1mm error, then you need 0.1mm backlash on both gears, but that's only a rough guide. It also depends on whether backlash is tolerable for your application, in that case you might go a bit higher just to be on the safe side.
@@antalz thank you sir
@@antalz sir another question can i edit a .f3d file in fusion 360?
@@kennethfajardo5121 Yeah .f3d files are Fusion360 files
@@antalz copy sir thanks again
23:55 What is the t in the sin(t/Np) expression?
That's a Pi
I have spent all day trying to follow these steps to create a gearset with the dimensions and ratio that I need and it just isn't happening. You're video is great but I don't understand where you're pulling the numbers from to determine your gear dimensions in a way that works. I could just plug in the exact numbers you've used but I wouldn't achieve the results I need and wouldn't learn anything, I'd just be copying you blindly. I was trying to work with a modulus of 5, a pitch diameter of 185 and 37 teeth (Ring), 60 with 12 teeth (Planetary) and 65 with 13 teeth (Sun). They should work right?
I have also followed your instructions step by step but the space between the planetary gear and the ring gear is huge in comparison. I don't know if it's my settings that are causing different results?
@@DarrenHerbertII Your gearset numbers can't get equally spaced planets because of equation 2 at 23:40. I do go into the video taking toothcounts that work before I talk about the requirements, that's the only engaging way to structure the video. If you could export your file as .f3d, assuming you're in Fusion360, I could take a look what's happening. If you're in another CAD system please send a .step. My email is antal@creonova.nl
Your settings shouldn't matter, but keep in mind 37 teeth on the ring is low, 60+ is more common.
@@antalz Okay, thank you! I am still relentlessly banging my head against the wall. I realized my gear specs didn't adhere to equation 2, eventually. I've restarted with some new dimensions, I'll send you what I end up with. It's much appreciated!
How calculat angular velocity to RPM
I make planetary gear box how find out put RPM BY ANGULAR VELOCITY
The ratio of angular velocities is the same as the RPM ratio. The angular velocity is simply the RPM divided by 60, to get revolutions per second, and then multiply by 2*pi because there are that many radians per revolution
Is -.2 backlash enough for 3d printing?
It worked for me, but I also run a slight bit of negative horizontal expansion in the slicer. Print a 20mm callibration cube, and if it's a bit oversized you can use horizontal expansion to get it right on point. You do need all belts and screws tightened well, otherwise you will get too poor surface finish. If the callibration cube is off a lot, or if the difference depends on the size of the cube, then you got an X/Y E-steps problem, but that's very rare.
@@antalz Thank you very much. I take it I print a cube adjust the expansion print it again till it measures right? .01 and .05 now WOW!
@@KCreations4You Basically yeah. When I did it originally it came out to 20.2 mm or so, so I put in -0.1 to subtract 0.1 from both sides, then I ended up at 20.05 or something like that. This was years ago though, but my parts have been coming out pretty much bang-on every time since then. Getting 0.1 mm horizontal deviation is rare for me now. When measuring parts in general keep in mind the corners can round over a bit, I just measure around it, if you want to prevent rounded corners you gotta mess with pressure advance.
@@antalz Thats perfect cause I got 20.16 and 20.23 and I was not sure what to put in there. Your a Legend!
How do i know those twist angles? At 32:07?
The calculations for how helix angles relate to sweep twist angles you have to go to video 3 of this series. th-cam.com/video/re8-kYZjjyY/w-d-xo.html
Thank you!
This tutorial helped me a lot and it is nice to see you still help people here after 2 years 😊
please work in my design, my design will make that gearing do 2 times the turns it would normally
i hope you will work with me
you post diagram link for easy to see in fusion 360
There's a thingiverse link in the description, which has fusion360 files included. Is that enough?
Bro, i want to ask you
for example
Sun Gear = 12 teeth
Planet Gear= 24 teeth
Ring Gear= 60 teeth
If the sun gear turns 12 teeth 360°, the planet gear will turn 12teeth 90°
but in normal gear system it will turn 180°
why does this happen?
In a regular spur gear setup the shafts are stationary. In a planetary gear setup, the planet spins around its own axis, but it also orbits around the sun. In your example I believe the planet carrier will rotate 1/6th of a turn. Essentially the planet turns 12 teeth like you would expect, but 10 teeth are in the spin around its axis, and 2 teeth are in the planet's orbit around the sun.
I'm not totally sure I got the math right there, but that's the idea. The fact that the planet is both spinning and orbiting makes everything much more complicated.
Hey I loved the video so much, unfortunately I 3D printed the gears following each step and my gears didnt fit :(
Check what tolerances your printer makes. If they're very bad, fix that first. You can either make gears with more backlash in Fusion360, or add more negative horizontal expansion in your slicer.
@@antalz I tried with .3 of backlash and still can’t manage to make them work, what profile do you use in cura for gears?
@@mri3884 I use a mostly custom one. If you can accurately print a callibration cube I don't quite know what the problem is. 0.3 backlash should be more than enough. Can you tell what isn't fitting? Are the teeth too wide or too long?
@@antalz they are too long and sometimes the teeth of the planets are too constricted with the rings teeth. I’m going to try with .4 backlash and report it what minimum diametral pitch do you recommend for the ring???
@@mri3884 I would say a minimum module of 2, so a maximum diametral pitch of of about 12 or so? If the tips are interfering with the roots, then backlash won't solve your problem. Try using a negative horizontal expansion in the slicer, and ensure first you can print a reasonably accurate callibration cube.
Fusion isn’t letting me select the push pull and extrude together
I don't understand, Extrude and push/pull are two different commands so you shouldn't need to use them simultaneously. What part of the video is this?
for new people who might still have a tough time finding the ratios and doing the calculations, here is a small python script i wrote which for sun gear as input and planetary carrier as output. If there is anything wrong with it feel free to let me know!
for k in range(3,6): #number of planets
for i in range(12,17): #number of teeth of sun gear
for j in range(20,70): #number of teeth of planet gear
nr= i+2*j #number of teeth of ring gear
check = (nr +i)/k
intcheck= int(check) #creating this to check if the value is whole number or not
ratio= (nr/i)+1 #final ratio
if (check-intcheck==0):
print("Number of Planets : ", k, "Planet teeth : ",j, "Sun teeth : ",i,"Ring teeth : ", nr, "Ratio : ", ratio)
That seems pretty accurate, could be helpful for some. For readability, I would write if(check==intcheck):, seems more clear to me. Also in some cases you might go above 6 planets, geardownforwhat does that quite often I believe with his extreme gearsets.
@@antalz yeah that would be much better. I made this code thinking only people who are very new to the concept will use this code. I love his gearbox design. I made my own using his method and 3d printed it but due to some issues i wasnt quite able to assemble it properly. I wrote a short code for that also!
can you please share the stl file
The thingiverse link in the description should have what you need, but let me know if anything's missing
@@antalz sir I want to print this planetary gear in 3d print .
Can you share me the .STL file.
@@mdfaridhossain1044 You can find the files with the thingiverse link in the description
@@antalz yes got it.
Thanks 😊
2:17 Why is it 36?
At that point in the video no particular reason, but I've chosen that value so I can later meet the requirements for the planetary gearsets at 14:25 and 23:35.
@@antalz thanks!
Can the free version of autofusion do this?
I believe so, the limit on "extensions" refers to the manufacturing extensions. You should still have scripts and add-ins. The 10 active files limit still applies of course.
@@antalz ive only worked with NX. what do you mean active limit?
@@HeimdallAfBifrost The free version of Fusion360 has a limit of having 10 active files maximum. You can have more files, but those files have to be inactive. I'm not sure how bad it is, I believe it's actually not that bad, but they introduced it late last year I think, and I've had a pro license since long before then, so I don't know how good or bad the free version is. Regardless, I'm pretty sure you can still make gears.
@@antalz im gonna do planet gears for an assignment and we havent gotten that far with CAD in NX yet. So this is awesome for me. Although i need a radio of 3 or less. Awesome video, thank you.
@@HeimdallAfBifrost No problem mate, good luck! You can see the ratios at 28:10, for a fixed ring gear you just need to ensure that the sun has at least half the teeth that the ring has. Fixed ring gear is definitely the easiest to implement.
why dont you put teeth on the outer diameter of the ring and add another planetary to move the same speed so the outer planetary is bigger and it makes a 1 to 1 ratio increase torque
why didnt anyone put teeth on the outer diameter of the ring
Usually there are no teeth on the outside of the ring gear, because the ring gear is stationary. I haven't seen anyone do teeth on the outside of a ring gear, but it should be possible, though getting bearings mounted will be tricky.
A 1:1 ratio will never increase torque, because that would create a conservation of energy violation.
@@antalz i know how to but it uses a second energy source
Schitterend!
I don't know if solidworks' toolbox is a curse or a blessing... On one hand it can premodel Ring gears, without the need for any of this, just enter your values and job done. On the other hand the options are EXTREMELY limited. You have only the options of 14.5 or 20° Pressure angles, full millimetres of diameter, a minimum number of 10 teeth, modules CANNOT be entered, there is only presets which even at lower values only go in 0.1 increments, and 0.5 or more at higher modules. This makes it really hard to design gears when shaft distances are given as you can't have a non integer module to suit your needs and gear ratio requirements. On the other hand it's all industry standards. Literally every gear you make is just a variation of an already designed industry standard gear, and it comes preinstalled with all sorts of gears (helical, spur, ring, rack, bevel etc)
Yeah it's a bit of both. Nice that if you select a value, you can probably buy it somewhere. The pressure angle is hard to work around, but for the module you could perhaps use scaling. IE make a module 2 gear, then scale it by 0.5, then you have a module 1 gear.
9:42 the editing features is a little problematic in my case, I cannot select more than one object ...
Are you holding down control to select multiple features?
@@antalz yes, that's what I missed. I googled about it and found. Thank you
The formula for the rotation of the sun gear and planetary gear does not work. I've tried it 7 times.
What formula are you using, and what are the parameters for your gearset?
@@antalz I am working at 17:31 in the video where you explain the rationale for the formula needed to correctly sync up the rotation of the sun gear with the planet gear. Everything else up to that point is working perfectly as I have carefully followed the parameters given when using the gear making script. The formula I have been using is (56/16+1)*360. I've experimented with different versions within the formula, coming close, but not succeeding. I was able to get through early college calculus by the skin of my teeth, but it's not availing me much now. I'm brand new to Fusion 360 and 3D printing; so I am totaling fascinated and having big fun.
In the video you stated that the orbiting of the planet gear around the sun gear creates and additional rotation of the sun gear. Is that accumulative, i.e. do all three of planet gears contributed their own +1 rotation of the sun gear? Anyway, any suggestions/help you can afford would be greatly appreciated. As stated, I am thoroughly enjoying your lectures and learning quite a bit in my old age. Much appreciated.
@@daveyJ213 It's just a single +1, having 4 or 5 planets wouldn't change the ratios compared with having 3 planets. Are you motion linking the correct two joints? It's a link between the sun gear revolute joint and the planet carrier revolute joint, it doesn't directly involve the planet's spin revolute joint.
@@antalz Hey, Antalz. Yes, I am using the correct joints: the planet carrier revolute joint and the sun gear revolute joint. I went back and reconstructed the motion link, because I remember you saying the order of selection does matter. In either case the results seem similar. It's close, but no cigar yet.
I did a position capture after lining up the sun gear and the planet gear, before applying the motion link, but the sun gear simply will not spin fast enough to keep up with the planet gear. I'll keep working on it; I'll go back and check my work one more time. Thanks again.
@@daveyJ213 If you can't get it to work, send your file to antal@creonova.nl and I can take a look
Awesome stuff! Do you have a Hackaday page?
Thanks! No, it honestly hadn't occured to me to open a page there. I'll look into it.
What size is the new bracket?
I'm not quite sure what bracket you mean
@@antalz Sorry I mean the planet carrier. You made a new planet carrier but never mentioned the size of the new one. I assumed it was a 100mm like the previous.
Im asking because I have a small error. The 2 new gears I constructed using the circular pattern dont mesh properly.
@@kifter4254 I don't think the size of the planet carrier changed. Could you send your .f3d file to antal@creonova.nl please, and I'll take a look
@@antalz sure. youre a legend man. my first ever build on a cadding platform total noobie
@@antalz I sent it to you. Thanks again!
Thank you very much. This has been extremely helpful.
My pleasure, let me know if you run into any issues