My 3D Printed Harmonic Drive is Surprisingly Powerful!

This is my 3D printed harmonic drive (strain wave gearbox). It's easily capable of 10NM torque output and has surprisingly little backlash and deflection even under extreme loads. It may not be metal, but the performance is surprising! It's low profile, durable, and can be used in a few different configurations. And best of all, it's super cheap! The gearbox itself is less than $20, and then just add the price of a stepper to drive it!
If you would like to find out more about this gearbox or get the parts to build your own, the project is fully open sourced and can be found here:
github.com/DDeGonge/OS-ARM/tr...
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#3dprintedlife #gearbox #harmonicdrive

[@cavemaneca]

This is actually the most impressive 3D printed strain wave drive I've seen on KZbin. Hopefully the video gets the recognition it deserves.

[@3DprintedLife]

Thanks I really appreciate that! :)

[@Blox117]

cool but pretty useless functionally when you could just use a direct drive motor

[@Blox117]

and no, they aren't "100 dollars"

[@networkedperson]

@@3DprintedLife you are promoting a company whose cloud logistics division directly supports ICE kidnapping brown children, among other human rights abuses.

[@sonicsupersam7793]

@@Blox117um what?

[@StuffMadeHere]

I knew I recognized that voice. Hah. Sweet design dude. Using the belt is very clever.

[@3DprintedLife]

Thanks Shane, hope you've been doing well and congrats on your insane success! If you ever find yourself with one too many CNCs just let me know 😁

[@Whynot83848]

@@3DprintedLife😂

[@CNCKitchen]

Great work! Makes me want to work on gears and gearboxes again. Any idea on the efficiency of such a design?

[@3DprintedLife]

Thank you! Yeah gearboxes are a lot of fun. The efficiency is definitely not great, maybe 60% or so right now. I intentionally went for a very tight tolerance between the flex spline and housing teeth to keep backlash and deflection to a minimum. I'll be doing a lot more testing with this gearbox once I get my control board made and start building the arm, so I can throw in some efficiency tests too! Perhaps even comparing performance and efficiency of different materials used for the flex spline.

[@jessemenezes3274]

@@3DprintedLife I'd love to see a video(s) with the mechanism printed out of different filament and tests of efficiency and longevity. Would be cool to see the arm casing printed out of Carbon Fiber PLA. Thanks for the awesome content!!

[@Side85Winder]

yeah use a planetary gear box instead, actually you can buy a nema 17 with a planetary gear box with more torque than this off the shelf it has a 20:1 ratio, It might cost a little more but its metal and wont brake. if you had one on a nema 23 well you would have close to 2x the torque of what this one you made or you could have similar toruqe with a 10:1 ratio.

[@whyme6742]

@@3DprintedLife You can replace the flexible spline with a planetary gear and reduce the output teeth by the number of planet gears.

[@ClickItYT]

@@Side85Winder But what about the backlash? That's the most important thing on a robot arm.

[@mr_voron]

For interfacing shafts with 3D printed parts in a VORON, we use 20T pulleys with the top flange popped off, and with screws driven in to fully stabilize it. It gives you a solid and cheap interface between a steel shaft and a printed part.

[@3DprintedLife]

On yeah I built a voron extruder a while back and remember that feature. I'm not sure I have room but I'll definitely play around with this and see if I can make it work. Thanks for the tip!

[@mr_voron]

@@3DprintedLife if you’re tight on space, use the 16T gear. They are much smaller, but still provide better interface than the nut + set screw approach.

[@3DprintedLife]

@@mr_voron yeah true, great suggestion I'm definitely going to try and make that work, thanks!

[@Justkyrios]

This is what I was thinking immediately after seeing the screw/nut combo break!

[@gedr7664]

do you have a link to this? I can't picture it in my head

[@redshepard5306]

Cool project, great video quality, and most importantly, you were clear and concise about your thought process, you really brought us along for the build. You got my sub fam. Keep this up

[@nrdesign1991]

This shows a great amount of dedication!

[@rolandorodarte893]

Awesome video once again! I can’t wait to see the next one!

[@3DprintedLife]

Thank you random internet person!

[@Venom.427]

Satisfying the design manufacture and testing !! keep up the good work.

[@3DprintedLife]

Thanks for watching! If you enjoyed, check out some of my other videos like a pneumatic 3d printed liquid piston engine! kzbin.info/www/bejne/h5WrkKarZ5x3j8k

[@_blood_moon_proto_1500]

amazing

[@SnacktotheFuture]

try vapor bath of carburetor cleaner on the flexspline (pla) instead of the nylon ?

[@jbarnhart2653]

Nice, but your labour materials and equipment use seem to add up to a LOT more than the price of the lower cost arm you showed.

[@3DprintedLife]

@@jbarnhart2653 well labor for me yes, it's way more. But I'm doing all the hard work and releasing as open sourced so others don't have to. Materials and assembly time will be significantly under even the lower priced arm I showed (which btw that is the price of raw parts, you still have to build that arm yourself too)

[@jbarnhart2653]

@@3DprintedLife Yes but open source for people who have all the same equipment that you do. More expense. I've done a ton of 3D printing and fabrication and even the best looking, most popular and in my opinion well thought out projects and stl's require "tweaking", in other words a lot of the work you did, in this video. How much do you "pay yourself"? When I'm asked to look at stuff like this, it's at least $40 an hour. Price goes up the more tech and skill needed...only way down is by making a bunch at once...(no) but even then, I don't think that except as a "challenge" project that it would be economic. "Build your own..." usual involves love of the work or better quality, rather than saving money or time.

[@erikziak1249]

Brilliant design! Also, I really like that you do everything by yourself. I believe the experience you gain and all those things you learn when doing this is super valuable and the best thing is that noone can take it from you. I also applaud that you share with the rest of the world here. A true passionate inventor/tinkerer, enjoying the process.

[@3DprintedLife]

I learned a while back that I'm gonna end up spending more and taking longer by doing everything myself, but the experience and knowledge gained more than makes up for it. Usually. Sometimes I go too far down the rabbit hole and never finish projects

[@erikziak1249]

@@3DprintedLife I know. Have been down that rabbit hole way too many times.

[@michaelrechtin]

This is very well done! The testing with the load cell is genius.

[@3DprintedLife]

Thank you! Btw I've been following you for a few months now, really enjoying your content and can't wait for more! You deserve way more subs!

[@OfficialJervin]

@@3DprintedLife mentioning that you subbed to this seemly random cool guy earned you AND him a new sub

[@vishal01mehra]

So glad to find your channel. Love your work. Keep up!

[@londonnight937]

Outstanding performance from your harmonic drive design! I would be proud of it!

[@3DprintedLife]

Thank you!

[@jupiter909]

Fantastic video, all the best for your projects; Keep up the great work!

[@3DprintedLife]

Thank you!

[@sabtvg]

Incredible! Congratulations! And thank you!

[@longboarderebright]

excited to see the full robot arm in action! i always wanted one of those automotive car building robo arms!

[@3DprintedLife]

I am too! :D

[@totallyrandomlocksandpicks1213]

Awesome video and thorougher explanation of the thoughts behind design process.

[@3DprintedLife]

Glad you liked it!

[@AllAmericanBeaner68]

Never even heard of strain wave motors until this video, great stuff and just subscribed!

[@willfiguex1]

Good job! You have good production and good content, the work will payout. Keep it up!

[@3DprintedLife]

Thanks, will do!

[@raymonroe1983]

That's pretty epic 😍. Didn't even know that existed until now.

[@PhG1961]

Excellent video, very entertaining and also very well explained ! Really cool stuff !

[@3DprintedLife]

Thank you!

[@solutionhacker]

Subbed! Your design, demo, and open source mindset is amazing!

[@3DprintedLife]

Thanks I appreciate that!

[@gordon6029]

Looking forward to this build

[@deplorablesecuritydevices]

Exactly what I needed thank you!

[@christopherhurtle7167]

This is the first time I've seen your channel great video subscribed!

[@3DprintedLife]

Awesome, thank you and welcome to the channel!

[@3d_davej]

Wow! That was super fun and enjoyable to watch

[@3DprintedLife]

Glad you enjoyed it!

[@nickcox2481]

I JUST watched Tenet last night! Your intro was awesome!

[@3DprintedLife]

Thanks glad you liked it! I was definitely inspired by Tenet for that one

[@robgoodsight6216]

🤣🤣🤣❤👍...watched already twice! And thought exactly the same!

[@THESLlCK]

@@3DprintedLife that movie was fantastic

[@impuls60]

You should design in stabilizing rollers at 90 degrees to the main bearings. That would function as a limiter for oscillations at high rpm.

[@3DprintedLife]

Ahh good tip, I was wondering why some other designs had those bearings. thanks!

[@locomotioncreations]

Great video man

[@MrDayTwo]

Really enjoyed the video, thank you. You are a real engineer.

[@3DprintedLife]

Thanks!

[@MrDj200]

Very good video. I'm looking forward to seeing updates on the arm :)

[@3DprintedLife]

Thanks!

[@JasonLooseArrowAlso]

Thank you for this video. I appreciate seeing how it takes time and many iterations to develop something. It helps me to see this because you know a lot more than me and are way smarter than me and, while my projects are far simpler, I have to keep revising my designs over and over. They just keep coming out not-quite-right. Or, just wrong. I keep thinking smarter people just make things perfect right away and I'm doomed to fail because I keep making mistakes. It's good to see that nobody is perfect, but you keep doing awesome things and making awesome progress. Thank you again!

[@3DprintedLife]

No one is perfect, even though I try! Just wait until my next video, there is going to be a lot of pain and a lot of failure in it :D

[@JasonLooseArrowAlso]

@@3DprintedLife I'm going to be in it??? LOL **weeping**

[@dernicolas6281]

Great design and development. Well done.

[@3DprintedLife]

Thank you very much!

[@patricklaqua5590]

Nice work!

[@patricioruiz-tagle9706]

Wowowowowowow. Awesome engineering work

[@patkirk960]

Excellent work. very helpful to see so many destructive test also

[@3DprintedLife]

Breaking things is my favorite!

[@matijavinazza9861]

I'm making a robot arm for a school project and will probably also go with the steppers. This might come very useful. Thank you for making it open source.

[@costaliberta5969]

worthy of a subscription! hope you finish it, eventually! ty

[@3DprintedLife]

Thank you, and welcome!

[@simonmerrett]

Great video. Still appreciate seeing the progression, rather than skipping to the finished version. I'm sure by the time you have printed 6 you will have refined the design much more and need to reprint the first one! Don't forget that while the single design is attractive from a scalability perspective, your robot arm will thank you for making lighter gears near the effector and beefier ones near the shoulder. And with your parts being printed tooling = free so CAD time is your only real excuse not to have a couple or few sizes.

[@3DprintedLife]

Yeah all good points! I'm only planning on using this gearbox on the two main hinge joints for exactly that reason. I'm still figuring out how I'll handle wrist motion and the rotary platform, but I expect I'll go with a simpler reduction technique like just using belts.

[@sirukin7849]

This is insanely cool!

[@MauricioHernandez-de8is]

hi bro, that´s a lot of hard work!! thank for sharing your knowledge

[@3DprintedLife]

Thanks glad you enjoyed!

[@Furzkampfbomber]

I have zero idea about the math, I would not know where to even begin when I had to make something like this and then I would fail again when it comes to the software controlling the arm. And yet here I am, watching and marvelling at all this expertise and at the fact that people are actually making things like this at home. I mean, I have a 3D printer, I am sooo proud about the first thing I've made in Tinkercad myself, a soap holder, and then I see this guy... :D

[@willozfam]

Good job! Enjoyed your tongue-in-cheek style. Fits your fellow engineers very well. 😉

[@fonwoolridge]

Impressive work!

[@wejzu8516]

Amazing project well done

[@starkosaure7833]

Thank you for sharing!

[@laveenkumar5737]

Clear Explanation and detailing

[@3DprintedLife]

Thank you!

[@ghostyFPV]

your willingness to embrace so many failures is what makes you a goat

[@joshgray1331]

Excellent work!!!

[@3DprintedLife]

Thank you! Cheers!

[@soronemus8815]

Impressive work my dude!

[@3DprintedLife]

Appreciate it!

[@gerarddantel5931]

I enjoyed this video more than I planned on. Kudos for the cinematography. I enjoyed it all. You actually finally gave me an excuse to start working on a robot arm. Although I had been trying to stay away from the trials and tribulations that is a 3D printer, I'm at least thinking about it now. I love the narration, the troubleshooting, the production. I'm so impressed with all your skills. Keep it up.

[@3DprintedLife]

Thanks so much I really appreciate it, glad you enjoyed! :)

[@Grinstopher]

random reminder that CNC mills also exist

[@kpatrickm]

Haven't the slightest clue about any of that BUT really well made and explained video. New subscriber UnLocked.

[@3DprintedLife]

Glad you enjoyed it, welcome! :)

[@Bastanien]

In my experience Taulman Bridge is an absolute nightmare to print with, you need very high temperature enclosure to prevent warping. I switched to Polymaker CoPA and PA6-CF, both of which prints almost as easy as PLA, sticks perfectly to glue stick, doesn't warp, etc. As long as you keep the filament dry and your printer hotend can handle the temperature.

[@JoeWayne84]

Wow man nice job

[@NathanBuildsRobots]

If you're doing a lot of structural prints I'd recommend upgrading to a direct drive extruder. Even after calibrating my ESTEPS my bowden setups always have a tiny amount of underextrusion at the start of a tool path. This introduces a bunch of weak spots for a failures to occur, which will be even more significant under cyclic loading due to the way fatigue cracks form. I like the animated CAD visuals keep up the good work!

[@3DprintedLife]

Yeah, good point. I've spent a lot of time tuning to correct for this, but going direct drive would make everything a lot easier and stronger. Maybe one day :) And thank you!

[@R3d_8]

For anyone else with the same problem, esteps won't fix it, but linear advance will. You can also reduce speed and acceleration.

[@dersebbler9452]

Very interesting Video, love your stile. Subscribed!

[@3DprintedLife]

Awesome, thank you!

[@jsquirre]

I've printed with bridge.. make sure to put it and a heated dryer for ideal printing. I put the heating unit of a food dehydrator in a box with my filament overnight. I would use a more aggressive tooth pattern as well. The bridge nylon can either smooth the surface enough to become a bushing or with the friction weld moving parts into stationary parts.

[@aerball]

I create 3d printed torque sockets for capping bottles at work and using a 3/8 inch drive, we are regularly able to place 60 in'lb of force on them without any problems. They obviously wear after a while but we were really surprised at how much they could take for as long as they can take it.

[@dave_jones]

Awesome, the video with the finished arm is going to be insane!

[@3DprintedLife]

Thanks, I'm very excited for it! And thanks so much for the support on Patreon!

[@dave_jones]

@@3DprintedLife Glad to give what little support I can :)

[@formfunction3d247]

Use either a filled nylon like nylonX (carbon fiber) or nylonG (glass fiber) to reduce warping when you do decide to print the new flex spline. It will also add rigidity

[@narpat007]

great, want to see further progress.

[@ChrisMcNeely]

Mad skills there

[@Tormasan]

the Greatest video i ever seen please keep doing this project i want to build the same thing

[@3DprintedLife]

Thank you, don't worry I'm not stopping!

[@VLena_art]

This has been my dream project for so long!

[@3DprintedLife]

Well it's open sourced! Play around with it, make it better, or make your own from scratch. Don't let your dreams be dreams! github.com/DDeGonge/OS-ARM/tree/main/cad/HarmonicDrive75mm

[@VLena_art]

@@3DprintedLife I know! Thank you so much!

[@alphonsobutlakiv789]

Built a robotic hand when I was like thirteen, back in like 2008 maybe. It was all wood, with programmable tumblers with a live control override set up like a piano. It's glue didn't hold up to humidity long, so literally just fell apart over a wet summer. It used pull strings and springs, and later bands, very close to how a real human hand works. Can just copy the human body and only run a single moter to bring it to life with this method. To add a computerized element, the tumbler spokes can just be raised and lowered, still powered of the single moter. I wouldn't be surprised if someone else is already building something like it.

[@TurrentWolf]

Working with gear boxes daily i never thought to see them made out of plastic. I've never heard of harmonic drives in my field of gearboxes. The design principle is very similar to cycloidal drive gearbox. neat work!

[@3DprintedLife]

Thank you!

[@GMC997]

Subscribed! Very helpful information here buddy. Especially if you are on a very tight budget and want to build a robot.

[@3DprintedLife]

Thanks for the sub, and that's the goal!

[@you2709]

epic part my guy, about time someone solved the flex spline issues. Im definitely printing this- after i struggle with solidworks long enough to get the inventor files working :)

[@3DprintedLife]

Awesome, and oh no haha. I'll upload an assembly step file tonight!

[@you2709]

@@3DprintedLife Awesome, thanks a bunch.

[@Jackjan4]

Great video!

[@3DprintedLife]

Glad you enjoyed it!

[@Sixfeetund3r]

You make great videos! Keep it up and i bet you'll get way more subscribers

[@3DprintedLife]

Thanks! It's probably not realistic but I'm shooting for that silver play button by the end of the year 🖖

[@rowbearpucklebuck2331]

I am an old cannon cobbler and pocket watch tinkerer, so this is outside my interests but as an engineer and novice 3d printer, this is wonderful!

[@sKuNKdoSE]

First time here! Really cool video man! I scrolled down and expected more subs than 11.8k! lol ...Here's another one! 👍

[@3DprintedLife]

Oh don't worry, it's at 11.801k now! :D welcome!

[@BitSmythe]

This guy: designs, iterates, builds and programs complete, strong robot arm. Me: happy my vase turned out. You go, guy, kudos, cheers and congrats!!

[@3DprintedLife]

Thank you!

[@swannschilling474]

I subscribed for this project!! Since I am building an arm using Cycloidal Gearboxes...but always enger to learn! 😍

[@3DprintedLife]

Awesome, welcome aboard!

[@swannschilling474]

@@3DprintedLife Hope you'll make more on this one...I would really like to try to build one of these too! 😊

[@g.stefanstoica]

Instant subscribe, such a good content

[@3DprintedLife]

Thanks, welcome!

[@ChadKovac]

This would make a great gate opener!

[@tec4303]

Looks great

[@waynenewberry1032]

Very Nice! Most will never realize the amount of work and talent it took to do this. Hopefully some sponsors will see this and drown you with new toys.

[@TeraVoltLabs]

Great work! Much more eloquent of a design than my Lobster Claw Arm :)

[@lio1234234]

Simply Amazing!

[@3DprintedLife]

Thank you! Cheers!

[@tablatronix]

I didn't even know these drives existed, fascinating

[@DIYPlace_Create_your_World]

mmmmmm Cool Project. Have Fun with it!

[@3DprintedLife]

Oh I will, thank you!

[@Quork]

If you got delamination problems you can bake prints on the printed. Just cover the print with something (a box/aluminium foil) and set the bed to 80°C then leave it for 30 minutes. I do not know how much this increases strength, but on a basic make 2 parts and try to break both basis it makes a noticeable difference

[@sukhrajhothi1542]

beautifully told design story! :)

[@3DprintedLife]

Thank you! 🙂

[@aspitofmud6257]

Patterns Mom and Dad. Priceless!

[@Mike-tq9cg]

I just got a harmonic drive from harmonic drive. Without measuring (they are tiny), the teeth do look involute. The drawing and 3d model they gave me doesn't include any info on them, I suspect its their secret. Nice work on this, very impressive to come up with your own new design on something this complicated.

[@3DprintedLife]

Ah awesome, good to have some insider info haha thanks for sharing that!

[@muggzzzzz]

You could use an ordinary timing belt turned inside out, as a flexible gear ring. You could match two timing belts with slightly different number of teeth to match your gear ratio.

[@sfkjbg]

Amazing video

[@3DprintedLife]

Thank you, glad you enjoyed!

[@Bianchi77]

Nice video, thanks :)

[@3DprintedLife]

Glad you enjoyed!

[@uku4171]

I made a wooden robotic camera arm for a school project using DC motors from old power tools (18V and 12V I think). Very powerful, but loud and not very precise. For the gearing I just used a nut and a threaded rod at the end of the tool's gearbox. The threaded rod was good because it also stopped the arm from moving up or down by itself. The arm was pretty bad as the wooden structure was very unstable. It was also very unprecise, but I think that could easily be fixed with a few sensors and software. It cost me about 300$ (including the Arduino and everything else).

[@grahammcnally4799]

Wow. Very nice.

[@Simon_Rafferty]

Commercial boxes often use an eliptical bearing instead of rollers, which increases the number of theeth in contact. But, where do you get an eliptical bearing? You take a thin section bearing and squash it a bit in a vice! 3D Print an eliptical boss to fit tightly in the centre of the bearing to stop it returning to circular. With this approach, you can go back to your original toothed belt design, as the belt is stretched over the bearing, which removes (most of) the backlash. The combination of the two significantly increase the overall strength.

[@bootlegcaesar7481]

Looks very promising, incredible how much 3d printed parts actually endure before failure

[@3DprintedLife]

It really is, the tech has come a long way!

[@shashvatverma5673]

@@3DprintedLife Bro this is such a sick project love your work

[@takodragionextream3625]

I like that you show your own failures and go for a lower budget range ,most channels like this try and do it by whatever means possible

[@zydawn]

great work

[@3DprintedLife]

Thanks!

[@marcdraco2189]

Hugely impressive young man, you give far too much credit to others.

[@3DprintedLife]

I appreciate it, but I really couldn't have done this without building off of what other's have done!

[@jasonwilliam2125]

Nerd. Subbed. Awesome vid with fantastic entertaining narration.

[@3DprintedLife]

Glad you enjoyed!

[@oscarsorensen210]

Nylon isn't too bad! Just dry it and it'll print quite nice. Loves to warp though, I found printing draft shield helps, an enclosure would be better.

[@kylebrake1806]

I love your videos!

[@fishemrock]

hey ! great work. Nylon isn't really hard to print. I recently printed Taulman's alloy 910 Nylon on Ender3 v2 using stock glass bed and elmer's purple glue stick. It stuck pretty well without warping. The sample was flat on its long side, a 1 cm by 1cm profile that was extruded for 15cm.