3D Printed Cycloidal Actuator
ฝัง
- เผยแพร่เมื่อ 17 ก.พ. 2021
- I have designed yet another cycloidal drive! This one is different, though. Unlike most of my projects, it is strictly 3D printed. No CNC required. The cycloidal mechanism is also "inside-out". The cycloidal discs do not rotate, they only wobble, transmitting rotation to the output. This was also designed to maybe be used in a modular robot arm. It's also a 25:1 gear reduction.
Gain access to project files and support my work directly - / levijanssen
Follow me on Instagram - / leviajanssen
NEMA 17 Stepper Motor - amzn.to/3bnO9qn
Large Outer Bearings - amzn.to/3bkebL0
Eccentrically Mounted Bearings - amzn.to/3sh0fbF
Disclaimer: I may earn an affiliate commission when items are bought through this link. - วิทยาศาสตร์และเทคโนโลยี
I tried to “cut the fat” for this video. More time went into editing, and I actually kinda enjoyed the process! Hopefully it made it more enjoyable to watch. Thoughts on a robotics arm using something like this design?
Would love to see some section analysis or parts coloring in Fusion, to really make clear the mechanics. But you struck a good balance here imo!
Maybe for orienting a small solar panel also using a second one? Or a mirror which shines sunlight indoors ;)
It does make the video better! Your older material about coilgun design were a bit too verbose, but this vide was much faster and more engaging.
I'd be interested in seeing a SCARA plotter with this design!
Absolutely love it~! My first thought was you could add some gas support struts/springs to the side between the two arms to help take up some of those forces while it's extended out? Just a thought~ Keep up the amazing work man!
Very nice quality in content, video, audio and editing!
Bucket of water is a fairly accurate weight. If you don't have a scale, you can measure volume and use density to get a weight.
But wouldn't you have a problem with, that if the arm isn't completely steady the water would 'splash' around in the bucket
I cant imagine doing this in imperial units
Remember to account for temperature.
@@Philip_J Bottles FULL of water taped together.
@@aeiou75 How much does that matter between 1-99 degrees?
This is awesome! I'm keeping my fingers crossed that this stays exciting enough for you that you keep devoloping it into something even more awesome and useful!
Very cool design, and I love how you scrolled through the whole code to explain it as you went. Also, totally interested in seeing a robot arm made of these!
Awesome work , I'm looking to finish a five year project of my own and you have definitely helped me to understand several things that I need to take care of . You gained a subscriber .
This is just awesome!
I really appreciate your extremely well done videos and your objective way of looking at your own creations! Go on mate! Cheers!
I find the cycloidal drives extremely interesting :D
You should look at Paul Goulds cycloidal design , it's what Levi has copied
th-cam.com/video/FplpyZD1i1M/w-d-xo.html
Superb project! I had the same problems with squashed circles before I've tightened elastic belts of the printer.
dude! awesome work! looking forward, would like to see the next stage!! :)
This is so cool! Goes to show how much someone with a creative mind and relatively cheap tools can make...
Actually the design was copied fro Paul Gould
th-cam.com/video/puZUKE_Wu8g/w-d-xo.html
@@anonymouscoward9459 completely different design. all that it has in common is that they're both cycloidal drives.
The design of this thing is great! Amazing work!
Just discovered your channel. Informative and well made which makes this an awesome video! Good job and hope seeing more 👍
Nice one!!! 😊
I did an inside out version of a Cycloidal Drive with a BLDC... it reduces noise and weight, while increasing torque and speed...but at the cost of needing an extra encoder and expensive mcu, so using available and cost effective stepper motors is of course a very good choice in this scenario too!!
Great job. Yes make the robotic arm as that would just be fun to see and for you to do. A new printer even a cheep one sounds like a good idea.
Really cool! I´d definetly like to see a finished arm using those actuators!
Hell yeah! the Monoprice mini V2 my favorite of my 3d printers.
Awesome! I've gone through a few iterations of a harmonic drive but I have not been happy enough with it to publish yet.
Great project. Thanks for converting to metric units as well 👍
Awesome Design Levi!
I have the same problem with my MP Mini. On my MP Ultimate (Wanhauo Duplicator 6) circles are perfect. What a great project, cant wait to see what you do next with that.
Thanks for sharing! Cool project!!!
There's no proper word for the amount of joy that came up when i saw that this was printed on an MPSM
I'd give a pankake stepper a try... would make the build more streamlined. Brilliant idea by the way, looks very promising!!
I like your experimental & fun approach to designing new things. Your 3D printer is a nice tool to have, allowing you to _"extrude ideas from your brain 🧠"_ 🤔
Super cool! Robotic arm would be fun.
Well done Levi!
This is incredible, subbed, thank you
You can scale the 3D model in the slicer by a very small amount (e.g., 1%), independently for X, Y, and Z.
The OVAL PROBLEM in a 3D printer occurs because of one of the belts being stretched permanently. I faced the same issue b4, got it right by using a new belt
+1 for this, also the belt tensioners on the MP Select Minis aren't great since they're literally springs and can flex. I'd check out the USWaterRockets 6mm belt tensioners on Thingiverse.
If you tie a string on the end of your square tube and on the end of that tie a empty milk jug, you can apply a range of test torques by adding measured amounts of water to the jug.
6:45 what I did is buy a 8l water bottle, with that you can just fill it with water and use a kitchen scale to get the exact weight you need, its great for testing torque capacity at any possible weight
Been a while since I've seen somebody use one of those dual H bridge drivers on a stepper, had almost forgot there was an alternative to the little stepper drive ICs, especially the Trinamic magic ones.
Wow, crazy that it's back drivable! I mean, not super smooth, but not talking worm gears.
Cool stuff 😎
That's a great design. I'd like to see you do a whole arm.
I have a mini v1 and was able to fix an oval printing issue by tightening the belts. You should also ensure that the stepping values in the firmware are the factory settings. If they are not your scaling will not be consistent across all sizes of prints.
Great work
Going forward you may want to check Trinamic motor drivers, they drive motors with much more control that h bridges, and you they have evaluation boards that are affordable. Amazing work by the way!
Seconded.
wow, the quality of the video is much better :D
Nice job
Can't wait to try this on my resin printer
I'm happy I just discovered this channel.
Maybe a resin UV printer would make more accurate gears for this?
really interested in the refined open source version!
Nice information, thanks :)
very cool
Nice work - I have a similar project underway
You should get a smaller glass bed for your printer. (Or even better, a PEI flexplate) That extra weight is sure to introduce more ringing than necessary.
i think you could attach the potent to someone arm and be a sort of exoskeleton , maybe to help those having minimal arm issues
Nice project man! Although, don't get mad, the final result looks cooler than it performs: lots of play and it doesn't actually work like a servo (it is not positioning aware)
Perfect 👏
Nicely done. Cycloidal gears are something I’ve always found interesting.
If you wanted more precision and torque, you could use a worm gear system in a similar space.
a worm gear is a non-ideal solution for a robot actuator, because there's a lot of play or friction, and worm gears are necessarily non-backdrivable
Amazing design!
Cycloidal drives are cool, but you have to know it's the reason you can't move the arm anywhere near the max holding torque. By the time you get an actuator on the end of the arm, you'll be close to your 2.5 lb limit. Increasing the teeth per inch will help a little, but a planetary gear will be needed at the shoulder.
Very impressive. Well done.
T'es un génie 👍bravo 👏
Absolutely do more
Thanks for the metric torque!
Everyone's ragging on me for even thinking to mention imperial, I appreciate the thanks for the metric!
Great job !
Check different supplyers for printer stepper drivers, sometimes ( in 5 packs ) they can be cheaper than dual H-Bridge and cuts code to pulses ( steps ) and direction outputs making it easy instead of having a step table.
Cool project! May I ask how you expanded the build volume of your printer? Did you follow any guides or anything? I also have an mp select mini I’d like to see if I can upgrade.
Wait a second you're not Tom Stanton
GREAT!!
To the people who keep harassing him about his choice of units of measurement: Just stop. Use your own choice and respect his right to his choice. Nobody needs or wants your abusive expressions of your opinions whether they're overt, or transparently "subtle" like Mister "Accept The Scientific Language" down below. Grow up.
Hmm, maybe having seperate drive and position detection motors would be a good next step, to minimize the effects of stress and strain on the little plastic bits.
5:06 [insert me when X -joke here]
Hello. Could you please explain, what are the advantages of those BLDC actuators in small robot arms, compared to RC servos? Conventional servos seem to have higher power-to-weight ratio, while also being cheaper.
2:00 Here you were talking about the pwm signal caused by the stall torque or something. I'm currently doing a project and I am trying to find the best way of detecting the stall in a simple nema17 stepper motor. Do you have any suggestions what the best way of doing this would be?
There is some existing solutions for something like this, if I didn't misunderstand you. It's a small circuit board that attaches to the back of the stepper motor, and senses the motor position with a Hall sensor. Google "closed loop stepper motor" :)
@@OMGWTFBBQSHEEP yes I know those kinds of closed feedback loop stepper motors. Tho I can't seem to find any information stating that you can actually detect the stall instead of compensating for it. Do these boards have pins which allow you to check for stall?
8:05 You need your printer tuned in really precise for minimal gaps.
Yes!
Zig-zag a chain of them paired in a scissor formation all receiving the same signal acting a massive linear actuator.
Cool.
Amazing work! However do not confuse a potentiometer with a cheap trimmer. Trimmers (like your blue one) are supposed to be used just for infrequent adjustments.
nice
Yes, the ovals are probably from your x and y steps not being calibrated. Search for e step calibration
I am curious to see a robotic arm made from this cycloidal actuator. Can it be used for precision work like motion control, welding etc.
Is there any industrial part/mechanism that uses this reverse (inside out) form?
very interesting, go ahead please !!!
It seems to me those inner cycloidal gears could be rotating slightly and that might be producing most of the play in the mechanism.
That's very cool! where did you get those bearings?
hello, definitively interested in a full robotic arm. before changing your printer better tuneup your pulse per mm/inch to get real circle. a second printer is always handy also...
I have built a robotic arm with a similar cycloidal drive design, but one of the significant shortcomings of this mechanism is it cannot transfer a higher amount of torque, as shown in the video; when you try to move at higher loads, it starts slipping in the same way. @LEVI Janssen, do you have any solution for overcoming this slipping issue? It cannot be done by using a motor of higher torque as the current motor I am using has high torque, but the gearbox starts skipping at half of the motor's rated torque.
Good job,thank you for sharing ,if you cosider practicality/ease/aesthetic you get good grade for it ,need to work on precision/backlash
this is amazing
Great design Levi ✅✅✅
The robot/motor community is so divisive about which units to use for torque. I believe that SI units are superior to imperial units, but kg cm make the most sense in the usual armature lengths we deal with rather than meters and usually thinking of loads in terms of weight rather than newtons. Anyways, team kg*cm ftw
CNC'd metal parts and a stronger stepper and I think you have reasonably compact and robust design.
Is there are reason why you went for the justified but ancient L298, rather than a more modern Step-Stick A4988/TMC2208 or similar?
Micro-stepping should help smooth out motion and reduce noise. The TMC range of drivers also offer silent operation.
For robotics, you'll need some positional feedback, especially with steppers. A potentiometer at the very least. Optical encoders are better. There's a quadrature optical sensor available on a break-out board for around $3-5, and you can print your own encoder onto OHP slides or photopaper.
Hi guy, its ok? I have a question, how do you make the redution? What calculo did you do? I have a motor nema 17, what the better redution for this? Thank you man.
I wonder if you'll consider to show in detail the procedure to mount & connect that L298 have the same one but never managed to get it to work like you.... all or any help you give would be greatly appreciated....
Neat, looks awesome. Some of the play could very well be due to tolerances between the metal tubing and the screws. Threading on screws should never be used to center a smooth hole, only to clamp stuff together by lock into other threads. Maybe try shoulder bolts?
On this note, another option might be to use layered concentricity by fastening the bolts in question into threaded holes or through threaded inserts then surrounding those inserts or some form of hole posts with the hollow rod you decided to use for its stiffness and durability.
How about a worm gear? It would make the system a while lot stable when the worm on the motor drives the arm. The printed worm may collapse but a aluminium would be a good option.
Looks like a perfect chicken coop door opener/closer. 🤔
Very sleek design, it will be interesting to see the complete arm.
Is the "action" while moving under 5# load a function of the slack in the 3d printing ... Or something else?
It's backdriveable but it sends current backwards when it moves right? You can move it but you need to make sure that you have a capacitor or a power supply that can handle current going in the wrong direction
Seems like a great place to start from for a cheap-ish welding positioner??
It is pretty compact. what is the equivalent gear ratio?
What happens if you don't have the bearing but instead try some kind of greased sliding surface? I'm guessing the bearing is the most expensive, heavy and hard to find part. If a bearing free solution would work, it would make the design even more accessible!
My Project for my BS in Engineering Physics is focused on the development of a 3d printed actuator. I've chosen a cycloidal drive for my design as well, they're great! If anyone one is interested I'd be happy to share my work!
4:00 Yeah ... the bottom and top part aren't really designed for 3D printing. If they were, they would forgo the size reduction. (brought to my attention from the rough surface which would be the side on the print bed if designed correctly)
What 3d printer is that you have? Looks nice