I have made Powerful and Cheap, 3D printed robot actuator

Check out Fantom Wallet at: store.fantomwallet.com/ and use coupon code 'SKYENTIFIC' for 10% off.
High reduction ratio robotics joint for only 32$! This is the stepper version of my compound planetary gearbox. It has high reduction ratio (1:84). I plan to improve this version with the 3D printed slew bearing. And after I will design a complete robot arm with such actuators.
All 3D printable files are available for my 10 USD/month (and higher) Patrons ( / skyentific
).
Special thanks to my special Patrons: RobotDigg Shanghai, Shounak Bhattacharya, M. Aali, Matthew Harrison and Vikas Marwaha!
Please subscribe. This will help me to develop other projects like this, to bring the bright future closer!
One time donation:
www.paypal.me/Skyentific
If you want to help this channel, please support me on Patreon:
/ skyentific
Instagram: / skyentificinsta
Facebook: / skyentificface
Twitter: / skyentifictweet
#DIY #Actuator #Robotics

[@Skyentific]

Please put the like to this video. It cost nothing for you, and it helps me a lot to accelerate the robot revolution!

[@MrEngineer_]

OfCourse 😍

[@coco805]

Always looking big forward to your updates, this stuff is amazing!

[@Skyentific]

@@coco805 thank you!

[@lesto12321]

I wander if you could put the stepper in the shaft hole, i think there would still space for cables AND it looks like the gear assembly is as tall as the stepper, so you would half its height!

[@togowack]

You are right, Gear down for What has answered a big question, I am about finished a 6 axis robot based on his 149:1 plastic gear ratio which greatly reduces the cost of building such a robot at scale. This video is vindication that the math is right, though I haven't publicized anything yet. I encourage you to continue... plastic gears are a different ball game and sort of untried.

[@johnyoungquist6540]

Expand your tight plastic parts with a little heat to improve fit. Print over your captive nuts to lock them in and hide them. I always print a few layers over embedded nuts. Great design, nice job.

[@DaveInPA2010]

I would be interested to see if you run it for an hour or two in both directions to “break it in” and see how it sounds/runs, then post a short results video

[@omaraissani6255]

Yes, i would be interested too

[@Scott_C]

When James Bruton put his drive on the end of a pole and used it to push him on a skateboard for a few miles it did wonders for the smooth operation of his version.

[@morkovija]

That's what I call "democratisation of tech" the industrial robot based on those actuators would be so cool

[@jameshughes3014]

wow. just wow. at that price, building a robot arm is actually affordable. this is pretty amazing stuff

[@g.s.3389]

You are very good in designing gears in fusion360, it would be nice if you could make a video where you explain how you design a simple gearbox and the tollerances you use for 3d printing. thx

[@togowack]

The tolerances don't really matter, there will be backlash and elasticity. Either your software is up to the task or you focused on the wrong thing. My 6 axis robot is just about done and driven by high torque plastic gears same as this guy.

[@PhG1961]

Awesome video and what a great product. Excellent craftmansship and great ingenuity !

[@CrankyCoder]

I LOVE the cable pass thru!! Very cool that the backlash was so little.

[@Winallmoney]

This is probably the smoothest, quietest, 3d printed gearbox I've seen on youtube yet. Great work, thank you for sharing! Here's a like.

[@Scott_C]

Nice! Looking forward to the next iteration. Been subbed for a while, keeps getting better and better.

[@AA-gl1dr]

Amazing work. I can’t wait to find the time to eventually build a lab robot from all of this. Thank you for sharing your brilliant design with the world

[@antonwinter630]

great outcome. looking forward to see how much torque it has

[@andrewpusey6339]

Thanks for sharing this. Looks like a good design. I am thinking that flipping the stepper around and placing it off to one side of the gearbox so the whole depth of the unit is reduced ? Also close up the gap between the two halves of the gearbox and maybe place a thin PTFE sheet between them. Keep up the good work.

[@haenselundgretel654]

Reaaaaally good video! Really good gear system! Love it!

[@Morberis]

You did it again! Wonderful vid.

[@jcugnoni]

Very cool design ! Congrats

[@gadget2622]

I wanted a robot arm for some automation projects but was put off by the cost. This is brilliant!

[@btCharlie_]

Would be super cool if you could test the maximum direct load of the stepper motor and then test it again with the gearbox to have some numbers! I'm thinking of motorizing my standing desk and using a cheap motor would be spectacular, even with the large gearbox.

[@nilscarstensen3844]

This is the content i subscribed for! Good job!

[@martylawson1638]

Nice gear-box. Really looks like it can move heavy loads. I think you'll be able to improve efficiency and max load by adding a cage for the planets. This type of planetary drive puts a lot of "twisting" torque on the planets that try to skew them. The cage then helps keep the planets aligned so they work better.

[@Skyentific]

Thank you for advice! I will think, how to do this without additional bearings.

[@martylawson1638]

@@Skyentific Even without ball bearings, a 4-5mm diameter steel pin in the center of each planet will provide a lower friction path for the twisting force on the planets.

[@togowack]

It needs to be much thicker to handle high loads. No real problem though. The question is the end goal.

[@forrestfrank1470]

I think the weak link is the connection to the motor shaft. The solution is actually simple. Amazon has a shaft sleeve that has a D shape female and a square key male. It was loose but the remedy is to shim the flat part of the shaft to remove the slop. It works very well.

[@kingcheese3795]

Perhaps an idea on all these actuators is to increase the outer ring gear thickness, to further support and strengthen the external connection, the output performance is always very good but I feel the week point is the connection to the item to be actuated, maybe to bring it in line with the total output torque of all the internal gears, maybe it would allow for better performance, as this seems to be the weakest link in the chain I apologies in advance if this has been addressed.

[@tomdgr9767]

This is incredible !

[@malachilandis9542]

I like seeing you modify designs to take advantage of or mitigate the shortcomings of 3D printing. Definitely would recommend these videos to mechanical designers who are just starting to use 3D printing at work and need to adjust their design philosophy accordingly.

[@barrettdent405]

Amazing work

[@learnMax]

amazing work! I hope to build a motion-controlled camera arm one day for stop motion animation work and this would be perfect (especially considering the price!)

[@Meccanokinematics]

Well done!

[@manyirons]

Now we're talking! This is excellent!

[@andresolaresjurado]

sooo good, great video as always! :D

[@muskku]

thaaanks!1 in love with your works!

[@Vancha112]

I would love to see a very cheap but good 6dof robotic arm made with this. Sounds like an amazing idea for an open source arm!

[@klausnielsen1537]

Great advance. I like it and see gret things ahead for this

[@statorworksrobotics9838]

Fantastic, a more realistic lower price. I'm sure it can take a much larger stepper too. I've been playing with worm gear wiper and and window motors too, some of them you can even back drive. And can't beat the price for the punch.

[@stefanguiton]

Excellent!

[@aarondcmedia9585]

Fantastic!

[@NielsNL68]

nice work

[@Big3dprinter]

Awesome video.

[@ezurakuro]

This is a very good innovation from brushless motor to stepper motor since brushless motor is overpriced in the place I lived in. Probably will also try these to be intergrated with other type of actuators. Nice job mate!

[@Wol333]

Really appreciate the low cost design!

[@marioacjr]

Awesome!

[@MatterLabz]

Beautiful! I continue to be impressed by your Fusion design skills. I'd love to see you do a video series on your process. That could be as simple as a screen recording as you design something. It would be long but people would watch it. With a little more investment in time you could speed up the video a bit and narrate over it. Or you could go all in and sell a video course showing the design of a couple of gear boxes and some extra parts. I'd certainly pay for it. I realize this would distract you from robot to R&D but you would expand the community with more people who can get involved in what you are doing.

[@DaveInPA2010]

Design idea: What about instead of motor hanging off the side, you folded it in on itself, and put the motor on the inside (180 degree opposite orientation from current)? Then you mount connection points/flanges using outside rings? Yes you lose cable feedthru in the center but for an elbow or knee joint, or a non continuous rotation (

[@BrianBoniMakes]

Robot people want the hole in the middle but I'm building a large winch and the hole in the middle could be a large shaft that would support double bearings on both the input and output. The motor on the outside also allows room for multiple inexpensive motors to drive even higher loads.

[@DaveInPA2010]

@@BrianBoniMakes *Some* robot people want the hole in the middle. I definitely admit there’s times I run cable through the coaxial shaft of a normal motor, vacuum feedthru, even a rotary pneumatic coupling. But I’m building a mech, and pancake drives on either side of hinge joints like elbows and knees are a favorable option. Something like a large Kollmorgen ServoDisk pancake motor with a surrounding orbital planetary gearset.

[@BrianBoniMakes]

We're living in the golden age for sure. Sounds like a nice project, you should show it off.

[@GearDownForWhat]

Thanks for the shoutout!

[@garysimmons1631]

Nice job I really enjoy your videos.

[@lumotroph]

Brilliant

[@Jamichen88]

Amazing content as always! Just curious about the actual noise produced as I am looking at utilizing a similar system but am trying to reduce vibration and noise as much as possible. Do you have a decibel measurement or comparison? Are you running micro steps for the stepper? Also how does this compare to the BLDC version in terms of sound? Sorry for all the questions lol

[@viniciusnoyoutube]

Amazing.

[@ralfsobe5529]

A design only as an articulated axis, enables many alternate rotating rings with a full zylinder wall of these rolls !

[@eelcohoogendoorn8044]

If going for a lower planet count (I think 5 is a nice number), it becomes easier to build some elasticity into the planets, and print them with a slight negative clearance, so you can really drive backlash to practically zero I think. I have a python script to generate all possible imaginable gears of this type that allows you to search for gear ratio and optimize various other things, I can try to put that in a usable state online if you care. Here is a nice setup with gear ratio of about 50: ((23, 22, 67), (18, 22, 62), 5). You can create almost any gear ratio up to 1k, though im not sure its always best; internal friction increasing with external load like pinching probably gets worse if you do. Internal friction is also a great reason to copy the triple-ring structure of GDFW; with only two rings each planet gets skewed in place when the unit supports a torque which increases internal friction a lot; whereas with three rings this mode of distortion is supported a lot better.

[@eelcohoogendoorn8044]

@TheShneedle Its a little bit more than just a standalone script; it makes use of this python library of mine. So to use it you should clone that whole repo, create a conda environment, and then you should be able to run the test in that file as entry points into various pieces of functionality. I tried cleaning it up and documenting a little but it still isnt the best. You can use it just to find interesting gear ratios and plot those configs, but there is also a bit of functionality to export to STL for printing.

[@eelcohoogendoorn8044]

@TheShneedle Note that it will compute gear ratios or any config; [r1, s1, r2] means ring1 is the motor stator and mechanical input, sun1 the motor rotor, and ring2 the mechanical output. Any such combination is supported, though this classic config (or with 1 and 2 swapped around) is generally the most interesting one, producing the highest ratios.

[@eelcohoogendoorn8044]

​@TheShneedle Also note that it does not do any involute gear generation, but rather uses cycloidal profiles. While I havnt tested this in practice yet, I feel that the cycloidals are preferable since they are meant to be printed anyway, and they form a nice and continuous printable contour. But more importantly these gear teeth should be fine bearing substantial normal load, whereas a typical gear profile with its more inclined pressure angles really does not take kindly to that. With these teeth it can act kinda like the Archimedes drive; relying on elastic deformation of the gears to generate a preload and eliminate backlash. EDIT: youtube seems to be deleting any links I post as well as any new entries to this thread in general; perhaps this edit will work, but look for pycomplex on github; then look for a file called test_compound.

[@albyboy4278]

Awesome 😁

[@alexmair3613]

Sir the force is definately with you!

[@shecterelectric432]

I would love to see a video of you programming this. Its nice that it works, but how would you do it if you want it to move an specific radial distance? or how can you let know the encoder at what position it is?

[@GuilhermeRochaFast]

You rock!

[@yukit119]

3:32 Coop Card ^^

[@Skyentific]

Yes! There is also Migros card there :)

[@yukit119]

@Skyentific 😜

[@arnaudherault9168]

you are the best skyentific

[@beefsand419]

Nice

[@mosiyukvasil]

I'm expecting that using a general brushed DC motor (i.e. motors used in cheap cordless drills) instead of any brushless or stepper one will make final actuator price lower but torque will be bigger

[@sukhrajhothi1542]

i love all your videos, could you please show more 3D CAD clips to better illustrate motion :)

[@user-rd3lj4gn4s]

Обалденно!!! Ты настоящий мастер.

[@rusrus4524]

акцент русский ----рашэн эмигрант ))))

[@user-rd3lj4gn4s]

@@rusrus4524 а может сербский

[@TheNamelessOne12357]

You promised to do torque test. Hope you'll do it in the next video. And you should also print it in Nylon PA6 or PA66 and test it's durability under load. Don't forget about shrinkage.

[@HarvardYoung]

AMAZING! Do commercial actuators (in articulated robot arms) have built in limit switches? Or is that function usually separate? I would think a "home/reset" feature would make movements repeatable.

[@davidnilsson5721]

Does this perform better than cycloidal drive that has bearings? E.g. backlash. Thanks for great content!

[@adisworld3255]

Can you explain how you drive the stepper motors in this manner?

[@pcinfor2010]

Hello, I loved this solution, are you available to download this piece to modify or print?

[@SergeiSugaroverdoseShuykov]

if i remember it correctly, half of genesis robotics idea for plastic gears was in preloading of planet gears so they wouldn't have backlash.

[@andycrask3531]

Can you use a thrust bearing between the rings?

[@JM_Tushe]

That's an awesome double planetary gear. :o Which software did you use to make the inner gears? I know how to make the normals, spear gears, helical, herringbone gears, but i have no idea where nor how to design one helical internal, not even a spear internal gear. :(((

[@benjamin1832]

can you make a model with the stepper in the middle or in in that hole, to be the same dimension in outside? I don’t know if explained well 😅!

[@dhruvbose8294]

I legit got a deja vu at 10:33

[@rogerioalcantara5383]

Hello, I follow all your videos here in Brazil, I would like to know if the file is available for printing or if I can buy it?

[@zyxwvutsrqponmlkh]

I subbed when you had less than 100 subscribers, thought you had too few and still do.

[@openTaylorBot]

Would you be hard to add position feedback for this?

[@sezgincelik]

Harika iş.

[@husamwadi2635]

That sounds pretty good for 3d printed gears. What I expected: CRRRXXHHRRRRR What I heard: zzzzzzzzzz

[@Skyentific]

Exactly!!! :)

[@gordonpromish9218]

somehow I keep thinking that these printed part actuators would be best applied in making a larger and metal-capable CNC VMC that would then allow for relatively inexpensive fabrication of precise steel gears and aluminium frame elements - call it a bootstrapping method.

[@ozr2222]

can you tell me the name of your grease? I have been looking forever for a polymer grease... Nice video!

[@maca5800]

is it possible to make it spin faster?

[@abdullahcakan]

do you mind design a serial elastic actuator and pid control ?

[@_HowHardCanItBe_]

I really liked the injection molded gearbox from genesis robotics. I'm not sure why people still use expensive harmonic drives

[@Skyentific]

Have you use it? I really want to try it!!! :)

[@ezurakuro]

the reason why people use harmonic drives because it can be used with high reduction ratio with zero-backlash while maintaining the small size (depending the reduction size also). Also HD is expensive due to its material (which is mostly metal)and the manufacturing cost.

[@_HowHardCanItBe_]

@@Skyentific I have not tried one. However, one of my coworkers tried one in Hannover, he was really impressed. They have promised a lot for a while now, and I’m not impressed by the progress… I guess they have some issues that are not clear from the demos. Injection molded gear boxes might sound too good to be true

[@_HowHardCanItBe_]

@@ezurakuro I know that, but Genesis Robotics promised all the same functionality for a fraction of the price. I was hoping for low cost injection molded gearboxes to be easily available by now...

[@BrusnickiRoberto]

From where do you get the bearings?

[@miguelangelsanchez9061]

A bearing with airsoft bb's in the middle would be really nice!

[@PranshuTople]

Did you calculate the torque it produces? If yes, then how much is it?

[@Skyentific]

I have not measured the torque. But I hope to have at least 30Nm

[@ulugbekhamidov2529]

CAD files will be available only for "some of patreons" 12:28 ? (((

[@rverm1000]

is the place to get the 3d print files to try it?

[@charleswatts1864]

Have you run one of these continuously to see how long they last?

[@bgrant1512]

Did you every solve the axial load issue?

[@DPTech_workroom]

👍

[@Dom1mus]

Ю ноу, ю ар пёрфект . Ай лайк йор ченел вэри матч. Эдюкейшен фор масс, инженеринг ар юзфул фор эвриван. Сэнкью ! А если без шуток ( давно наблюдаю за каналом и знаю что умники как я достали ) огромное спасибо вам за вашу работу . Очень вам благодарен, удачи в нелёгких начинаниях , лёгких съёмок и благодарной аудитории

[@Skyentific]

Спасибо большое за такой классный комментарий.

[@holski77]

POG

[@bnelsey]

How feasible would it be to make smaller versions of this? Would it be even cheaper or more expensive?

[@Skyentific]

It is possible to make it smaller, but not too much. In smaller version, you would need to use smaller teeth on gears, and 3D printer should have enough resolution to 3D print small teeth properly. I think it is possible to reduce the diameter to maybe 80mm or 70mm. I do plan to make smaller version. Ideally I would like to have three version: small, middle size, and this big one.

[@Skyentific]

Price-wise: smaller stepper motors are a little more expensive, but smaller bearings are cheaper. So I suppose one going to cancel another and the price will be more or less the same for small, middle and large version.

[@bnelsey]

Alright thanks, looking forward to those videos!

[@alistas35]

Hi. I am working on my own robot arm which is 6 axis. I used stepper motors and drivers. Mechanichal system is due to finish. I am designing the robot to package cases. So, i am going to use it as a case erector.My question is a about software. What software should i use? What is the best way to get the mechanism worked? Should i use a cnc controller card or something difference? My robot is 6 axis

[@imadesomething]

Did you make your own gearboxes?

[@Jkauppa]

diy 3d printed motor, true brushless dc, copper electromagnet or em + permanent magnets, solenoid coil ring + radial same polarity magnets, just add bearings, or use that planetary as the bearings, lorentz force based, non-touching, if more detail/instruction needed

[@Jkauppa]

external measurements for the position

[@megasqrt]

Hi, you build robot arm this chip gear?

[@hayoun3]

how did you calculated the gear ratio???

[@MakeitModitBreakit]

How many ft lbs of torque does this output?

[@nesbionics]

Hello, I don't understand what type of lubricant to use

[@moses5407]

I'm assuming this is not backdrivable?

[@steamcastle]

who much PLA did you use?

[@sylpisophia5612]

i love the accent ❤

[@odinata]

Anybody know where "DearDownForWhat" disappeared to? Also, 28BYJ-48 please.