I want to thank you for sharing this knowledge with us, as you can see I am not the only one who wanted to have this knowledge more digestible. I once had a full-time engineer trying to make one and we couldn't do it. Thank you very much.
Only the one axial bearing for the output won't be enough, you'll need a second ball or tapered roller bearing to account for radial and angular loads. Your design won't be able to stay on axis and have a lot of friction and deflection with radial and angular loads.
Thanks for the great job. It was confusing a bit for me how this mechanism works! But the version that you are presenting here is much simpler than others. For example ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-OsS9-FzKN6s.html&ab_channel=HowToMechatronics presents another version! How different is yours than his? Would be happy to see your explanation.
This 3d printed drive with all the expensive hardware in it (giant thrust bearings etc) will end up costing more than an all-metal simple planetary, and close to as much as a metal professional cycloidal. Unless the expensive metal bearing components can be reduced, these things are basically fun but pointless.
I have built a very similar functional robot using fully custom designed parts (servos, cycloidals, pcbs, gears, programs, ...everything). Would you be interested in taking a look at it? I'd be very curious to know your thoughts and see if you come up with possible improvements. Thanks
Hi techer , Thanks for your guide. I have question, in section 'Design the Cycloidal Disk' step 2, 31/49=0.632, but in your guide set value to 0.622, could you please tell me why ?
@@thewhiteowls1320 Hi Techer, I cannot refer your guide to redreaw the "Cycloidal Disk" on Solidworks , I always hung on step 7, Solidworks cannot offset profile on parameter 1.5mm , maxmium value is 0.7 , however same parameter can be set on Fusion 360, but profile cannot closed, cannot extrute to a cube. Clould you please share a guide on solidworks? Thanks and Best Regards.
Any indication of the efficiency? A similar design in youtube with steel pins instead of bearings has an efficiency of 35% which sounds like a lot of waste. Also do you have any ideas if the wear on cycloid discs would be acceptable? Thanks
I should read your post before apply steel pins to my design instead of bearing. Using PLA as gear material is not a good idea, too soft and friction too large. My gearbox efficiency is 34.9%, which makes my motor can only operate at very low velocity. After I switched to bearing I got 86.5% efficiency, but because I use it to lift heavy load, my gear wear immediately and causing huge backlash.
mathematically, the cycloidal disk does not slide against the pin but roll over it instead, very much like spur gear. It gave me the confidence to stick to dowel pin as long as i am able to manufacture the cycloidal disk as close to the calculated profile as much as possible.
How is the durability? Plastic gear over roller pins is probably ok with some grease, but the plastic over plastic output pins could wear out. Really nice design btw.
the secondary lines are for drawing the cycloidal profile. In actual mathematics, the cycloidal profile is created by a smaller circle rotating around a bigger circle so the secondary are formed by a small circle rotating around bigger circle.
Hi niyas, the ratio in cycloidal drive are selected based on torque requirement. And also, we try to select numbers that 360 deg can easily divide. for example 360 divide by 30 is 12deg per pin and 360 divide by 48 is 7.5 deg per pin. weird number like 19 complicates calculations
hi man, very cool design! I'm trying building one from your stl with PLA but i'm having the problem that the cycloidal disk can't move because of lack of enough space from 3mm pins. The disk is stuck. I notice with multiple prints that maybe the holes for the pins are a little too small resulting in bad positioning of pins. Do you have any suggestions? Thankyou!
Hi thanks for liking the design. typically a printed part is slightly oversized around 0.1mm extra on each side. You have to try print some simple sample and measure if the actual size match the designed size and apply offset to your 3dprinter accordingly. My Prusa does it for my automatically so i have no issues, i am not sure about other printer. And in another video of mine, i drilled the hole through 3mm drill bits to ensure it has enough clearance for the pins. hope it helps!
@@thewhiteowls1320 I got the same problem as davidenardi536 experienced. It seems the set of 'cover & disk casing' and 'gear & disk casing' are not matched. cover and gear are unexpectedly lardge and disk casing is small. Thus, i decided to fix the size of the disk casing but, it might be able to affect the whole reducer in a negative way. I am worried but I will also try to fix it :)
@@익명-n5d I increased the size of pins holes and I increased the circle's diameter where they are generated and after several prints I managed to obtain a very good zero backlash result. I think that this could be the best 3d printable drive for NEMA 17 on youtube. I also tried very a promising harmonic drive solution (ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-DlZzknQdTlU.html&ab_channel=FlexibleBlade) but it is more exprensive because of bearings and more fragile.
It's unbelivable. I was trying to find or build the cycloidal drvies for my robotic arm. But, this is the best cycloidal drvie ever i have seen. Perfect. Thank you for your kind explanation and free publishing
Yes harmonic drives are the gold standards in robotics but they need specialized equipment to manufacture. I am just a home based hobbyist so cycloidal drives is the best I can come out with. I am glad you are back with robotics!
Yes that will be quite helpful. Currently, I am going at rather slow speed so vibration has yet to be significant. I guess i will need to implement your suggestions when I am doing high speed rotation. Currently, having a single disk seems to distort the torque pin quite badly and lead to significant backlash, i am guess that a second disk would help balance out the forces.
Thanks for kind words. It took me several attempts to get to this final design and I learnt alot. I try to document what i learn on my website. Feel free to drop by!
