an easier robot arm actuator... 

If the the gear had a herringbone sort of pattern, that would eliminate thrust along the axis.

This is what access to 3d printers does. It brings ideas into reality that we didn't even dared dream about. I am so impressed with where this is going.

Next step would be to add a planetary gear set to that for more constant load application. Having 3 driving cycloids could smooth things out significantly

Excellent, very clear and detailed explanation on the workings! More ideas for you to consider: 1. having 2 motors drive it can give you more power, better rigidity (positioned opposite), and control over backlash (just advance one motor further to tighten the backlash). This way you can move a robot arm quickly and not precisely, but have it arrive very exactly and without backlash to target point. 2. have many (herringbone) rollers between an outside housing like now and between an inside off-center rotating-wobbling disk like in cyclodial drives. You get higher gear ratio than this and way more contact points to stress - hence a stronger gearbox.

Fantastic work, I love how clearly you explained the creation of the cycloid :D I'm tempted to try and make multiple stage internal eccentrically cycloid reducer. Looking forward to your next ideas.

As I continue to find more of your videos I'm more and more impressed with your concise explanations and great ideas. Keep it up mate!

Very glad youtube waved your video at me! Extremely handy to see python code in Fusion 360 doing the sort of thing I need, and your presentation is spot on. Thank you. I'm about to dive in and explore all your other videos.

Super unique design! I really like these gearbox experiments.

For those figuring out why this is different from a regular big gear with thread on the inside and a smaller gear attached to the motor, one revolution of the input here is results in the outter gear rotating one 'teeth', while with regular gears the big gear moves with the amount of teeth the smaller gear has. In another way, you can say that with this system the driving gear only has one teeth.

So cool that you keep working on this project!! Nice update, makes me want to build one!! 😇

awesome videos.... delighted I came across your channel!! thanks for sharing your knowledge

Very nifty. Good job. The video didn't waste any time which is good. We can all freeze or replay these so there is no need to go slower (given it mostly shot over my head and thus got a rewatch).

Amazing work and the narration is even better. Very impressive

Very fluid, clever and clear demo, thank you!

Thank you. You are faster than I expected. Looks really good.

First vid of yours I’ve seen, subscribed!

Your videos are absolutly perfect! thank you a lot for the work you do.

Gosh, you int 'alf clever! And so refreshing to hear a British chap doing interesting stuff on RU-vid. I hope I haven't broken any rules. 😀

This is exactly where I am now. Thanks for the insight.

I need to learn that snap your fingers trick to speed up my projects 🤔 Wonderful video.

You have a very soothing voice.

Interesting.. thanks for trying the inside out design... Might not be as good, but now we know for sure.. every data point is useful!

I need to try one of these

Just rewatched this. One advantage of thei gearbox, is that it can have a hole through the gear, which is perfect for wires.

Excellent content, yet so humble :)

Now looking forward to seeing you try a planetary cycloid version of this :D The goal is to have high gear ratios, but also reduce space as for a dynamically balanced cycloid gearbox, we need minimum 2 and even 3 cycloids for fully balanced dynamics.. That increases space and multiplies the number of bearings or rollers needed for real gears that aren't just 3D printed. So if a planetary cycloid hybrid gearbox can achieve the same or higher gear ratios than a regular eccentric cycloid in less space or the same space, then it would be an interesting and highly practical innovation.

Amazing video!

If you're putting the drive gear into an elbow like you have here, you don't need gearing teeth to go all the way around the circle, the elbow stops the rotation at three or so teeth on either side of centre. So there's some space saving available in this specific use-case.

friction is always the first hurdle , complemetary forces are next . the trouble starts with wear of parts due softness and over-use . but very nice transparent developing , inspirational

you could improve this by adding more macaroni pinions like a hybrid with a planetary gear set to distribute the force. Then mirror the mechanism like a herringbone gear to get rid of any axial forces. I might have to try this!

Very good video. Just a recommendation wile editing use a plug-in that removes the strong "ss" from the audio

It looks like you have room for a second motor and input gear. 2x the torque, and the second motor could be clocked to eliminate backlash!

A second gear along the inside, so the driver sits flush on both ends would create more torque relative to its volume and you'd really see the magic of this design. You're only grabbing on the outside: You also need to grab on the inside.

what you could do, to give it more strength, is have the outer ring, the eccentric gear and then an inner gear that helps stabalize, the gears.

Amazing design and implementation. I do wonder about the Fusion 360 script though - all those individual line segments will eventually cause performance issues, and make the breps very complex. Doing a best-fit spline, with a tight fit and lots of control points, may be an option. Or using arc segments. This is similar to how the "Smoothing" function works in F360's CAM workspace.

wow it looks so easy

Nice work! The python code and visualization is especially helpful to show exactly how the curves are generated. I wonder if there would be any way to make a planetary version of this. There's an awful lot of empty space inside that could be filled with more pinions to multiply the torque capacity, but I'm not sure how to go about driving them, unless just putting another of the same shape pinion in the center would do it.

Herringbone arrangement with multiple driving gears synchronized via a timing belt (chosen for anti-backlash, but perhaps gearing would suffice?) could increase the torque capacity and eliminate the need for a large outer bearing (at the cost of several smaller ones for the driving gears).

Now put 3 (or 4) of the internal gears 120 (or 90) degrees apart and put large planetary gears on the end with a small sun gear. Probably not too practical since another set of gears will introduce backlash, but there's still internal space that could be used to increase the gear ratio.

6:00 - In fact I do have a crazy idea 🤪. - It could do no less than do away with all metallic bearings and screws. - And perform even better. - No joke! Namely: Drive a single planet of a tapered roller cycloid gear-bearing containing at least three planets. Best thing a single fat 3D printed screw can pretension the whole assembly together to zero backlash! The tooth trajectories need to be of a (soft sinusoidal) herringbone shape in order to prevent slide-out of cone roller planet gears. In fact I made a prototype of such a gear-bearing. Just not driven at a planet but passive. Guess I need to make a video showing it off such that it gets more clear what I mean.

you could split the outer piece into several plate-like layers with straight edges that are stacked together and then fit bearings along the little pinion. It would then not be a continuous mating surface anymore, but rather about 6 bearings that sequentially push on the outer part. Backlash would probably become unbearable and you'd have trouble mounting the bearings on the little part, but friction would be eliminated.

I think there's an interesting trade off to find between the height in mm of one sweep of one tooth, and multiple sweeps. In this example, 3 sweeps at 10mm or 1 sweep at 30mm.

Maybe you can try to make one a little bigger, so the motor fits inside side by side with the worm. Then you connect the motor to the worm with simple gears or a belt. The advantage is that it would have a neat form factor with no protruding appendages. You can also use small bearings if you place them to the sides, and make the cycloidal cage as two facing cups with a central axle.

he took a hit at the comment section a more advanced version of so many experts joke well done mate

Impressive....

"so let's do that" amazing haha

I'm thinking planetary internal cycloidal gearbox......should be able to make it smaller, and between the extra contact area and those areas operating in opposition to one another the torque capacity aught to be pretty good for the size. Another thought is a roller design. It looks like a planetary gearset but all parts are smooth. The balance between load based friction and the properties of the lube help determine torque transfer qualities. A benefit to this design is that slippage is accounted for when overtorque is applied. The rollers simply slip without the mechanical deflection and breakage of a gear or other positive engagement system. When the overtorque condition is over the transmission simply goes back to work. This is ised in a supercharger design from a few years ago but I'm sure it has other applications.

you don't NEED to use big bearings. gears on shafts can be mounted with bearings just bigger than the shaft, you press the bearing into the center of the gear. You can also have nested shafts like in a motorcycle clutch basket

it`s good to see all these ideas played with they can all lead to new and ingenious ways of doing things... I suppose an improvement for strength at least would be to have multiple Rotors inside that internal cycloid... When looking at it though it`s all sliding surfaces.

can you tell me the procces to get the equation of the offsetted hypocycloid to use in Solidworks because a normal hypocycloid is discontinuous and cannot to drawn by equation driven curve feature.

I hereby declare this as the "noodle drive".

Excellent design. What are your thoughts on a herringbone design, will the off-tangent forces be too high? Also is it possible to put 4 internal gears to spread the load around? I've replicated your last design with four bearings at 90deg on the inputs cam and four stepped cycloidal gears at 90deg phase shift. I will try and do the same with your current design. I will use your python code to generate the internal cycloidal profile. Many thanks.

Could you do an internal and external gear, and herringbone booth?

Now THIS is a worm drive.

Steeper cycloids and or less of them in the orbiting pattern as well as a larger pinion for more strength?

I became lost at some point. How is the pinion gear diameter determined? How about the offsets? I do not follow code all that well. Plan to try Levi Janssen's method of manually plotting out the cycloid. Only do it on the inside like this one. Need some help. :)

nice

use this drive as a cable spooler so you can utilizee smalller bearings and slim down your arm joiunts by making them cable actuated.

We’ve been using worm gears for articulation for… ever.

How does this compare to helical gears? Also, you might want to try a herringbone style because then the small gear won't move around.

what would happen to the movement if the gears ar longer/deeper

You could experiment by placing the bearings on the gears inside

Could be posible put an inside cylinder with the pattern with a free axe in front of the motor power axe. and maybe this way the axe can no "jump" as easily?

Hey, wouldn't this desing allow for several inputs? Since its hollow, it could be possible to just add more motors, maybe even add another gear on the center to keep all of them synchronized and keep the input gears in place to avoid skipping.

Anyone have a link to a tutorial that can help me learn how to do the rolling circles in python?

The cycloid gear looks to have a lot of wear surface making a plastic version have a short lifespan. I wonder if somehow you could use ball bearings in there, so the balls rotate as the friction surface, like how a ball screw works.

At the end, it looks like the bearing is slipping. Is it possible to have the cycloidal gear deeper? Seems like it's almost just rolling the outside gear. Love your content. This is the type of channel that I go to youtube for.

The next step would be an in- AND out runner, wouldn't it? Two opposing pins, one on the inside, one on the outside. Is that even possible due to the different diameters of inside and outside? 🤔

Would it be possible to combine this with a planetary gear? Thus having three rolling pins that are driven from the center with the motor? It might only get a 1:1 between the sun and planet gears, but it might increase the rigidity as loads are distributed.

Gearbox will take two stepper motors and that will be doubling torque, right?

How about to add more drive gears?

What about herringbone gear?

I don't understand why the output was not a smooth rotation, but instead slightly jumpy. Could somone explain?

I like this idea!Do you think that having more pinions driven by seperate motors would increase the torque? What if you had three pinions ganged together by a belt and driven by one motor?

Would it make sense to double the pinion at the opposite side, coupled with gears to the motorized pinion?

With so much empty space inside the big gear, could you fit the motor in there?

Wo dering where can get those bearings?

please make a planetary version

Improvement: If you rotate the shape of the pin through a multiple of 360° it can transfer more force to the outer ring. Changing the geometry of the pin, making the shape a little bit more complex, the 'relevant' contact surface (the part applying force) increases and you get more torque for the same part count. If the material itself holds up, you can double or triple the torque.

There is continuous gear engagement, so why does the assembly rotate at an inconsistent rate?

How about 90 degrees version? Small (worm) pinion between two discs?

What's the gear ratio? Did i miss it?

What if you made it more like a worm drive? That should make it thinner and still allow for back-drive-ability with that style of teeth.

how did you smooth out the cycloid curve and inverte it @2.17 to 2.18 ?!

I had to idea to adjust your script to create a planetary gearset where we move the small gear to the centre and create 3 planets that mesh with this small gear and the ring. So far, not getting the geometry right for the planets!

Can you make it as a plantary gearbox?😊

Where can I find 3D parts models?

Could this be arranged in a planetary fashion?

A "smooth gears" with Zero teeth would be two wheels rubbing each other, the most simple form.

Wait how did you create a sketch in fusion360 from script?! I‘ve kinda been looking for this exact feature!

I am having a lot of trouble increasing the number of "pins" and decreasing the pin radius without getting any odd overlaps, sometimes it looks pretty good but when I try to put a circle around the ring gear in the sketch fusion360 crashes every time.

Couldn't you move the motor closer to the center to make it smaller?

What if you have three internal pinions that support it, you would not need that external housing with bearings.

Everyone wants to do magic, but no one wants to learn the math to do magic

Where are you getting the large bearing from?

Why its better then planetary gear reductor?

how do you know the angle of the arm? there's no encoder.

Супер!

Any chance we will see these fusion files on get hub?

So... its like a worm gear but colinear with with driven gear?))))