High Torque Cycloidal Drive (NEMA 23 Motor)
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- Опубликовано: 4 окт 2020
- I design and assemble a cycloidal actuator based around a NEMA 23 stepper motor. Hopefully, this design will eventually be used in a robotic arm.
Gain access to CAD files and support my work - / levijanssen
The motor I used in this project - amzn.to/2GonCgU
Disclaimer: I may earn an affiliate commission when items are bought through this link. 
Наука
Removing pins may remove overall friction, but having more pins will have more surfaces for load distribution
Instablaster
doesn't make a difference if it can't move at all ;)
Cool project. Honestly its always a success when your part doesn't end up smoking, or melting, or breaking.. You get my meaning.
You made your own driver for the stepper, then designed a rugged metal pin and delrin based cycloidal drive and made it work!! What makes you think there is something you can not do? So well done. Keep it up 👍👍👍
Saw another video on Cycloidal drives where small bearings were used on all the contact surfaces - they demonstrated the design _is_ back-driveable.
yeah, James Bruton I think ;)
Looks so neat man... Im being mesmerized by all the different implementations of your idea!
Oh, this is a very streamlined design, I like it.
When designing for 3D printing, keep in mind that every measurement in Z has to be a multiple of your 3D printer's Z step size. If it isn't, your parts will be off by whatever amount is necessary to bring the height to the nearest z-step. Also, use machinist's feeler gauges to get your bed dead nuts accurate.
Yeah but you have to think about the first layer too. Because for adhesion you squish it most of the time
For simplicity i stick to all dimension being 1/10th of a mm tolerance and use that as layer size
@@BrosBrothersLP There is the elephants foot setting for that to compensate the overextrusion in the first layer.
@@FreeOfFantasy the elephant's foot setting just adjusts the xy expansion of the first layer I think @BrosBrothers is talking about the not perfectly defined hight of the first layer ;)
Adaptive layers solves this issue to a great degree.
Dude, your work is so incredibly inspiring 🦾
Dude , just the preview of the video is astonishing . I subscribed !
You need a second disc to offset the vibrations for when the 1 disc hits the pins.
Yep, with the cams for each cycloid disc set at 180 deg to each other.
@@owenjones9608 I see... That's beautiful
Your output shaft can only do circular motion, however your gear moves in a wave form around your motor axis. Pining these two together creates a lot of friction. Using long holes towards the center of your output shaft would allow for the wave motion of the pins and no sticking.
nice job,and especially done with your own design and realization. Congrats
This is a really smart gear box. Loved it
I was surprised to see you had just 4k subs. I was expecting around 2 million subs. For such amazing and original content, you are underra
ted. Good job lad.
Wow! That was fun to watch! I would ABSOLUTELY want to see pulling a car with this! What an amazing device! :-)
...though some hammers are more hammer-like than others. Love the Adam Savage quote. And, I too have found that particular style of pliers to make a really good hammer on many occasions.
You made a stepper driver...my world just got rocked.
Beautiful idea an pretty promising mechanism
Very compact and nice 👍🏻 I was thinking to 3D print one but after seeing this I think I’ll go the laser cutting a Delrin sheet instead. Thanks for sharing 👍🏼
It is a realy good proyect. Actualy, it look prety profesional and in the same line of the clasical way stepper motors look.
Wauw! Cool project. Little tip: don’t mess up clearance and tolerance... 😉
Wow, really great video! Love it 😍
I think you drilled out the wrong holes. You need to allow eccentric motion between the output drive pins and the white cycloidal gear.
Yeah I don't know how it would even be able to turn without that, interesting
Right, that is why it doesn't have a contineous and smooth rotation as the acrylic is being smashed by the 4 Pin (from output shaft).
Good job! I tried bearings instead of pins for the roller and got smooth running.
If your system is similar to mine, how did you ensure the straightness of the output pins? I think this is my primary issue.
@@LeviJanssen I had the same problem so I used a second disk/plate on the other side of the lobe. My gearboxes, though, are pulley driven so I can assemble them from both sides - I don't have to stack parts on top of a motor - www.franksworkshop.com.au/wordpress/2018/03/04/3d-printed-hypocycloidic-gearboxes-iii/
Awesome job, like the use of those pins, brill
Just a note regarding attaching the NEMA23 motor to the black plastic. The screws are intended to be inserted from the back of the motor toward the face of the motor. Epic job btw. I'm going to try building one with a brushless motor. Might might a good servo motor.
3:24 tape the hole up first I know there is a bearing, but metal shavings/dust+ magnets are just something that will give you a head ache.
would be pretty cool too see you test this baby out, maybe puts some weights on a pulley and see when it cant pull anymore ?
I think some grease will help smooth out the motion. It's common to use things like white lithium grease in airsoft gearboxes that have high torque and plastic/metal components, can hear a difference when properly applied.
good work mate! love it.
Great design, interesting.
Thank you
Completely off-topic from the video, but what camera are you running to record?
Great ingenuity !
I think most cycloidal reduction drives have two sets of gears with 180 degree offset lobes. That may reduce your backlash somewhat
The offset lobes won’t reduce backlash. The purpose of the 2nd lobe is to eliminate vibration. Any mechanism which includes an eccentric rotator will have vibration. The 180 degree out of phase counter-rotator cancels it out.
As for backlash, if a cycloid is manufactured with the correct tolerances, there will be zero backlash. All teeth are simultaneously engaged. The lack of backlash is why cycloids and harmonic drives are used in robotic arms. Without the lack of backlash, repeatable, precise positioning is not possible.
Cool video. I would like to see a test on the torque. Thanks for posting.
Have you tried a full 3d print version of this build? I suspect it'd be more challenging to get the right tolerances.
looks really cool, I would buy this if I had a use for it
Mist have been great to put the whole thing together
Liked your video. Good job for the equipment you're using. Would've liked to see a test of a 1ft-lbs. winding lift or until stall for maximin force.
great job
Hey Levi, cool vid. How did you get your measurements to make this actuator? I am trying to design parts of a tape recorder atm, referencing old tape players, but am having trouble recreating the gear mechanisms exactly.
impressive design :)
nice design!!
Very good attempt
Great job
Ounce inches?
Burger pattys per hot dog...
Metric is the answer
My reaction was pretty similar xD
My cursor instantly hovered frantically above the "thumbs down" icon ... imperial "units" gives me the creeps :-/
@@jorgenskyt I know,
So complicated and frightening.
Unicorn turds per full moon
Also I wonder how this thing turns at all, considering the "wobbly" wheel seems to be directly connected to a fixed output. But maybe I overlooked something.
And the whole project should take about 15,6/31 metric light yards of time to complete :).
From your stepper motor specs (and your input power settings), what is the expected torque?
design a direct drive 3d print head using a very small stepper motor and this concept.
Second that :) I only found one project using a cycloidal gear for an extruder. Wonder what's the reason we don't see this more often for extruders.
@@neur303 There is too much slop in the mechanisms as well as too much friction. Therefore it would have horrible backlash in an extruder, and would extrude inconsistently. Planetary gears are superior in just about every way to this. Of course this does allow a bigger gear ratio in a small form factor, but the negatives aren't worth it.
@@Chris-hn4lp I read quite the opposite. That they minimze backlash in comparison to other gears.
@@Chris-hn4lp It seems planetary gears offer more torque per volume. Which would be quite reasonable for a direct drive as lower volume should also equal lower weight.
But I still believe there's more to it. Like you wouldn't be able to use a planetary gear with plastic gears. And the cycloidal gear should be a lot easier to manufacture.
www.machinedesign.com/news/article/21829580/comparing-cycloidal-and-planetary-gearboxes
@@Chris-hn4lp yeah this a one of the few designs without backlash, not that it is an issue for the extruded as it can be correct with extra restart on retract ...
If you need pins to go thru 2 or more plates, place the plates together and then push the pins thru all of them. Otherwise, when you are pushing the second plate onto the pins that are already inserted into the first, any imbalance will try to bend your pins or wallow the holes they are mounted into.
nice work, but I think pins on shafts greatly weaken the shaft by subtracting up to 40% at a crosssection. Grinding a flat spot is much better IMO.
Hey boss, what about the coilgun ?
A little hint for making those full depth cuts through metal, use cyanoacrylate glue to bond to a metal base that acts as a heat sink and cut all the way through your thickness of stock to be cut. If the metal stays cool enough (by keeping your depth of cut small enough) the glue will hold throughout machining for thin parts like you fabricated. When the stock your cutting gets too thick, the side of your cutting tool will grab and toss the part with this technique with full length cutting flutes, but you can cut thicker stock by adding a draft angle to just keep the tip of your tool engaged with the part when cutting deep. To release, heat the metals and the CA glue will fail avoiding warpage and dinging from manually shearing the joint (a little acetone soak works well too, but takes longer). This and some of the other good machining tips I see in the comments will really improve your finished parts.
Doesn't the cycloidal disk push against the pins such that you're relying on the pin frame not to deflect?
Genius!!! Curious for the lifetime ... Can you run it loaded for a few weeks?
Awesome achievement.
Holy shit, this is amazing.
I'd love to know more about your 3 axis mill, i've got a little 3018 and its just not enough, along with just being too damn small
Not the cycloidal great design I was looking for, but still very interesting. I guess I was looking for harmonic gears
3:30 this is why I have nightmares at night lol
We're you cutting steel with your cnc router? Could we get a tour of your machine?
The wobbly vid was funny at first but got to be an eye strain. Being a person working with mechanical devices, might want to find a camera mounting with some isolation from the work table.
As a side note, having recently been to the dentist, I was a bit fascinated with the ceiling mount for the work light, with it being totally free within it's range of motion and total isolation from everything else (except maybe the floor above). This won't cover all needs though, which is why it's just a side note.
Thanks for sharing.
do you have any indication about the wear of the cycloid disc against the steel pins?
Oz/Inch? Please use Nm 😎
If you need reliable and good stepper drives, I recommend Trinamic.
Great job! I think not continuous (not smooth) rotation of the output shaft is caused by step rotation of the step-motor multiplied to gear ratio (x20).
divided, not multiplied.....
@@fabricioleinat Right. My mistake
You should use tabs for holding your workpiece when cutting aluminum, you get a much better-cutting line and not such a cleanup hassle.
I recently decided to design a 3D printed cycloidal gearbox and throw it on top of a 2300kv brushless motor... After a lot of fiddling, I actually got it to work. I think the ratio was 29:1
It ran for 10 glorious seconds. Then the motor windings burned and the magic smoke came out of the ESC. I think my problem was that the main gear was sitting right on top of the housing. Even though I put some grease in between them the friction was still too high. I was planning on putting some ball bearing between them but I just don't have the time.
They are a bitch to design and manufacture but it's wild how such a compact gearbox can produce 30:1 ratio.
Very interesting👍
What is the play angle of the output element?
How much actual torque can it produce?
Very nice! What 3d design program do you use?
What is the reduction ratio of this gearbox?
how about some grease inside ? that should help
sir, hayırlı olsun birader, hindistandan selamlar
Hey, I really like your build. What kind of aluminium is that? It looks like you should go for higher feeds, the chips are way too tiny.
This way the end mill produces enormous amounts of heat, because it mostly rubs over the surface. It will definitely die sooner than later :)
Also it might make sense to go for holding bridges, which are easier to remove. Just my two cents. Did you make progress with the uneven rotation speed of the gear? How would you consider to fix it? Best
The hole in the square black piece that sits on the motor should have the exact same size as the pilot sticking out of the motor. It's going to be a standard size for any motor of that NEMA 23 size.
Just watched your video and want to say good job. Looks clean and efficient. I'm just getting into fabrication and still learning which tools do what and their names. I'm curious to what the machine you used to carve out parts is called, is it another type of cnc machine? Lol sorry for the noob question.
Hope all is well
Thanks,
Jesse
Also any recommendations on a decent affordable 3d printer?
How is the backlash on this puppy?
If you ever do such a project again think about using the tmc 2209 drivers they will remove all noise and are controllable over a single wire. Cool mechanism tho
what length were the Ø4 pins and what size bearing did you use?
I would reccomend using a much shorter endmill on your router, like only a couple mm longer than the thickness of your material. That'll improve the cut quality and reduce chatter
10:31 what if put bearing instead of pins? that reduce friction but i dont know if still add torque.
i admit im a picky person n have n eye for problems but this was a pretty dam good video man u dont have a bunch of sophisticated tools, but youve made aLOT work with what u have i respect the hell out of that if u keep makin videos like this youll do good for sure i hope u have more like this minus the mandatory ads :p jp
Awesome! Did you shave down the bolts before drilling out the pins? (Maybe those bolts were the only problem?)
Great results! So few people have discovered cycloidals.
Can this be made using only a cnc? Or would it have to be bigger (using a 3mm bit).
I did grind down those screws. This certainly can be made with only a CNC. I would have done that had I had thicker plastic to cut out the base. The only thing you’d have trouble with would be the hexagonal holes in the plastic bearing spacer. I used a 1/8 inch bit.
@@LeviJanssen oh I meant: did you test it with ONLY grinding down the bolts (without having drilled out the pins)?
An easier setting for your nema23 might be an arduino with a cncshield, a drv8825 or better stepper driver and estlcam as control software. Much easier to set up and vary.
I only made a custom drive because I didn't have one lying around. A proper shield/circuit would have been desirable, yes.
@@LeviJanssen it's just the arduino with a "cncshield" for about 10 bucks at aliexpress and a stepper driver like a drv8825 or a tmc2208.
Try to design for a 1:10 ratio if you plan to use in robotics. Also the pins inside should be able to rotate as the eccentric wheel pushes and leans on them (not rattle though)... maybe have them on tiny bearings? Also, maybe lubricate the inside of the mechanism...
You can fix a non constant rotation speed in software if its repeatable/regular.
The clamping on the cnc router gave me chest pains. Great video though 👍
Was looking for this comment.
I have a question: would it be possible to make a functional, useful cycloidal drive on a 28BYJ-48 stepper?
Good Question!
Sure. Its only a matter of construction techniques.
@@maxhouseman3129 I wonder if the decrease in size would make it bind....
@@odinata If the whole construction is smaller, than it should work.
NICE MODIFICATION ,, I HAVE A QUESTION , ON REST WITHOUT POWER SUPLLY HOW MUCH IS RESTING TORQUE OF THAT MOTOR , WILL YOU ABLE TO MOVE MANUALLY ON RESTING SRATE & WITHOUT POWER SUPLY
I have noticed that you never put any grease or lubricants in your gear systems you would greatly reduce friction and increase produced torque values if you used some grease...
Based on your wasteboard, I see someone's been making some ear savers.
Hmmm what is it does it get BBC I player
Those ridges that are supposed to keep things precisely in place should be deburred and cleaned up.
A perfectly round shaft? What do they expect you to do with that?
I don't get it. How does it work?
14:33 the motor has laggy internet connection
Which 3d printer ?
As other people mentioned, you drilled out the wrong holes. The holes in the white piece needed to be bigger
I am jealous bro. Of your tools.
Can i have your drawings to try on my cnc ??? Ty and nice video