Designing a cycloidal drive in Python and Fusion 360

[@devanshgarg31]

This is one of the best and the sleekest cycloidal drive designs that I have come across

[@roTechnic]

Thank you. I really appreciate the nice comments :)

[@peterhenson823]

Not a fan of subscribing to KZbin channels, but for your wizard-like knack for classical mechanics, design, and robotics, I'll happily make the exception. Your presentation style stays focused on the material and not building "clout" which is pleasant and unlike all other KZbinrs

[@pandascientist1]

This video and supporting materials are seriously so amazing. You show the full equation with a graphic, and also supply a script for generating these in fusion. I was very surprised to find that fusion doesn't have a equation driven curve function, especially in 2023. If it did then designing these would be easy, I kept looking online for a script to do equation driven curves and the one addon that I could find seems to have been deleted recently for some reason. You have singlehandedly solved all of my problems, and given me the knowledge on how to use the script feature to make equation driven curves in future projects. You're legendary man. Thanks so much.

[@7alfatech860]

This is a very nice, clear explanation of how to derive the pattern. And bonus with F360! Thanks.

[@roTechnic]

I’m glad you liked it, thanks for the comment

[@wesleyfernandes7665]

You are a wizard! Great project man. A year earlier and i would have used it in my college instead of hours trying to create the pattern through math equations. +1sub

[@roTechnic]

Thank you! Yeah, the equations to derive the shape are pretty intense! I find it much easier to think of things in terms of geometry than formulae.

[@jordanarata2019]

Excellent video! Clear, concise, and with examples to work with. Thank you!

[@roTechnic]

Glad it was helpful!

[@hardeep_sukhwinder8286]

Simply the best tutorial on design of a drive. I am going to subscribe right now. Once again thanks for this tutorial.

[@roTechnic]

Wow, thanks!

[@TheRealStructurer]

I’ve been tinkering in both F360 and VS but never together. Now I will! Thanks for sharing 👍🏼

[@roTechnic]

Happy to help!

[@shogga690]

Hi. thanks for sharing the code. I was trying to run pyplot cycloid.py to see the visualizations. However, when I run the code it creates the plot, I left click then it hangs after creating the blue circles. Any suggestions

[@kamilw10001]

This chanel is pure gold

[@tommurphy7157]

Great video, very well put together! I see new things I want to go run off and make! Brilliant!

[@roTechnic]

Thank you! Let me know if you make one!

[@GuyBluesummers]

A Fusion360 master class.

[@roTechnic]

Thank you 😎

[@germanvazquez4333]

Wow, excellent explanation!!! Thank you very much for sharing. Greetings from Argentina.

[@blake.slater]

Great Tutorial! Would you consider doing a tutorial on harmonic drives as well? Im having trouble designing my own on Fusion.

[@ironichoneybadger5066]

me too!

[@christianthier3457]

Minute 6:29: Why you type in offset of 3mm as eccentricity, but in python you have 2mm / 0.2cm?

[@roTechnic]

I think I was using slightly different contraction amounts - I was varying the contraction in the python example a couple of times to illustrate what it does, and what happens if you set it too high. Eccentricity = (rolling circle radius / number of pins) - contraction you can see the contraction will vary the eccentricity

[@johnfelt1089]

@@roTechnic Could we use that eccentricity formula in order to calculate the number for contraction based on a given eccentricity?

[@roTechnic]

@@johnfelt1089 yes, absolutely. Sometimes you want to vary the eccentricity and sometimes the contraction. Take your pick!

[@raghadmaraqa2759]

I think you are AWESOME!! Just keep going

[@huseinalrasyid00]

Hiii, thanks for the turorial, it's so helpful, but i got a problem here, i want to make 20 to 1 gear ratio, so i change the number of pins into 20, but when i make the circular patterns, the line not connected to each other, i hope u can help me with this problem

[@devanshgarg31]

This channel is at 65 subscribers rn, it will soon blow up

[@roTechnic]

thanks

[@devanshgarg31]

@@roTechnic 10k Now. Awsm!

[@ShawnHawkins666-33]

so a 60:1 drive would have 60 lobes and 59 pins?

[@Three2NineProject]

Amazing animations and explanation

[@akshaypadmanabuni2075]

What would the values be for 21 pins? for a 20:1 reduction

[@silverpc4611]

How about designing this with Onshape or Tinkercad. Not everybody can afford Fusion360

[@fozbstudios]

Question. How did you learn the fusion 360 python api? Find that I’m really struggling because the lack of type info in python pretty much eliminates any autocomplete(except for static utilities) and I’m constantly going to the docs to memorize what methods and properties everything has. Thinking of moving to c++ for better autocomplete. Great video

[@roTechnic]

I tend to prototype my addins using pyplot as that's a lot easier to remember and then convert them over to the fusion API once I have everything working. I still remember the days before autocomplete (I'm that old), so I tend to have a file with examples that I can refer to open as well.

[@fozbstudios]

@@roTechnic ok so it doesn’t really work for you either. Seeing some other videos where vscode magically knows the type of things and am curious what I’m doing wrong, as autocomplete “works” for static methods only

[@fozbstudios]

Example where it works fully kzbin.info/www/bejne/g3XPZYyjeKt3fbc

[@roTechnic]

@@fozbstudios Hmm, interesting. the type of autocomplete he shows in that video works fine for me. can you give me an example of something that doesn't work for you?

[@fozbstudios]

@@roTechnic using that video as reference my python/vscode wouldn’t know the underlying type of app, and thus doing ui = app., there’s no completions after the dot

[@AtomsLab]

Awesome build and tutorial, thank you!

[@roTechnic]

Thank you very much. By the way, I've just clicked through to your channel and now I can't stop watching your time-lapses!

[@constantinosschinas4503]

excellent content. subscribed to support your efforts.

[@roTechnic]

Welcome aboard!

[@kampfzwergxp]

Maybe i missed it but what is the relationship of the eccentricity to the other factors? I want to have 20:1 and increasing the number of pins to 20 (*2 from your example) and the contraction divided by 2 from your example makes it work nicely... but I seemed to miss why the eccentricity also needs to be divided by the same factor. I also assume there are limits on how much things can be reduced in one stage, before it becomes to difficult to actually move. But I really try to keep things as flat as possible and would therefor rather not add another stage.

[@roTechnic]

The eccentricity is determined by the distance of the point on the rolling circle from the base diameter - as the contraction increases, the eccentricity decreases as the contraction moves the point closer to the base diameter. I haven't found a good rule of thumb for what to set the contraction to, but instead normally start it at 0 and increase it until the shape "looks about right". you can also play with the pin diameter. with regards to the maximum reduction ratio, in a perfect world, you should be able to have any number of pins you like and still drive it, but in the real world, you have friction to deal with - each pin you add will increase the friction. if you want to go to higher than a 30:1 reduction (which is the most I've tried at this kind of scale), I'd either increase the size of this, or consider a different material like PETG which has lower friction (also LOTS of lube - PTFE grease works really well)

[@kampfzwergxp]

@@roTechnic I have 2 wheels I need motorized, both have an inner part with a slew bearing of 239mm. That’s the max diameter I can play with. The 2 wheels need to pull the whole thing which will weigh about 22kg. The wheel outer is about 400mm and it needs to drive just brisk walking pace. Hence I thought I may get away with a 15:1 / 20:1 and a typical small stepper motor…

[@roTechnic]

@@kampfzwergxp you should be fine with 20:1 and a good nema 17 stepper. Let me know if you need any help with the design

[@kampfzwergxp]

@@roTechnic do you have way to pm, maybe discord? I can show u what I have so far…

[@roTechnic]

@Thomas Schönfeld sorry for the delay in responding - just set up a discord server discord.gg/aj5dNAvD feel free to join and share your progress

[@ockemont]

Hallo, I’m a Teacher from Germany. I have no 3D-Printer, but I like this simple modell. Can I buy this one?

[@mrteemug5329]

Watched almost all your videos now. Absolutely brilliant ones, but I feel like your content might be privy to plagiarism or worse yet, stealing. A channel watermark is an eyesore sometimes, but your videos are so excellent, I don't want someone else taking the credit :D

[@roTechnic]

Wow, thanks! I must admit that I find watermarks super annoying on other people's content - but your advice is good - I'll experiment with some interesting ways of marking them in the next few videos.

[@peterhenson823]

Where did you get your bearings?

[@roTechnic]

I bought them from Amazon - in the UK that seems to be the cheapest way to buy a few of them with a decent delivery time. link to the bearings is in the video description

[@arjundas708]

Thank you nicely explained

[@radnukespeoplesminds]

Cool I might try this in cadquery instead of fusion360 though

[@roTechnic]

Awesome! If you do it, then I'd love to see

[@jsal92]

Liked and subscribed!

[@roTechnic]

Thank you!

[@jsal92]

@@roTechnic great content, I'm surprised you have so few subs! Only feedback I have is the audio quality, it's a it muted/muffled and somewhat base-y, otherwise good work!

[@roTechnic]

@@jsal92 thanks - I only started 6 weeks ago, so I'm happy with the number of subs - always want more though! thanks for the feedback on the audio - there's always something to improve, please let me know on the next one if I make it better

[@jsal92]

@@roTechnic I would suggest you invest in a quality headset, you don't have to spend hundreds, just something with flat sound, so probably not "gamer" sets lol. Maybe there’s a good openback design to 3dprint and diy, or maybe that can be your next project ;-)

[@Pawe-mx9wc]

you are ultimate badass

[@mberoakoko24]

Subscribed