I've spent quite the considerable amount of time trying to figure out how to properly design a cycloidal disk/gear. Hopefully this can be a helpful resource for others like me. Check out my new MOSFET modules: www.ebay.com/i...
When I heard you say it took you 2 years to arrive at this point it made me feel better because that's the amount of time I estimated just to get to this point myself. Thank you for your hard work.
I think this equation will produce the same curve without having to go through the process of setting up the circles and plotting points one by one: x = R * cos(t) + e * cos(N * t) y = R * sin(t) + e * sin(N * t) R = ring radius N = number of pins e = eccentricity t = 0...2pi Then offset by pin radius, same as in the video around 9:00.
I ended up using: x(t) = (bR + sR)*cos(t) - sR*cos((sR + bR)*(t/sR)) y(t) = (bR + sR)*sin(t) - sR*sin((sR + bR)*(t/sR)) z(t) = 0 where: bR = radius of larger circle on which the smaller spins sR = radius of smaller circle (pin radius) t = 0 to 2*PI
I just finished this tutorial and got it printing. I’m excited about the possibilities with this gear reduction. Thank you very much for teaching what you have learned.
Thank you, thank you, thank you for making this video! I like to build robots myself and I have a 3D printer on order. A cycloidal gear system is one of the things I want to try to build. This video should help a lot.
Man, right after yours utube shows a tutorial for same thing but in solidworks. Theirs is twice longer and not understandable at all. Just a video of someone silently designing something for unclear reason. So, great work! Thanks for sharing, it's very useful indeed :)
the 'point' tool is in the sketch>create menu. I also found I had to draw the lines and dimensions in the exact order and start/end point as he did, or my model did not react. Got there in the end, thank you
I just followed your method and it worked. On the points that looked too far apart I just added a few more points between the ones that were there to make it look smoother. It was nice to find this tutorial but all the deleting of constrains is a recipe for errors. I want to experiment making more cycloidal gearboxes in Fusion 360 but there must be a better way, there should be some way to do this automatically like the parametric function in Solidworks where you just plug in the trigonometric function and it plots the line. Keep up the interesting work, I subscribed!
I don’t think fusion 360 has any of those fancy functions, I’ve looked pretty thoroughly, but I guess it’s possible. I guess I’ve grown used to the tedium of this design method. it’s great to hear that someone found this useful!
@@LeviJanssen Got it. You can add a SCRIPT that will plot the points, here's a demo and it's already pretty close to what we need. capolight.wordpress.com/2018/07/02/how-to-sketch-equation-curves-in-fusion-360/
@@LeviJanssen There is a cool software, its called Gearotic Motion. It can generate several types of gears, including cycloidal gears. All you need is just to choose some main parameters and gear ratios. You can find demonstration videos of it on youtube.
I saw videos where there is a cycloid on the outside instead of pins, and where the output pins are kept in place. How do you design the outer cycloid relative to the inner one in that case?
I just started learning fusion this is my first project. Im not able to select multiple curves for offset, it is showing cannot offset a curve. Please help me guys.
I can draw and assemble all the part for the cycloidal drive, and get the cycloidal disk to turn right. How do you get the Output rollers and shaft to turn with the cycloidal disk?
@@FeartheLess Yes I did. I used this www.tec-science.com/mechanical-power-transmission/planetary-gear/construction-of-the-cycloidal-disc/ To set the inner pins to turn with the cycloidal disk, set your joints, go to edit feature first angle set at 360, Second set at 36
Would the little edge that appeared at the transition point between the semicircle and the curve after doing the negative offset disappear if you'd have traced the points in smaller increments?
Hello. Great job explaining the procedure! It sure isn't easy to convey something like this without confusion. I am wondering (and mind you it might be a premature question given I didn't go the trouble studying the cycloidal gears very much) concerns that sharp edge where the offset cycloid curve meets the circular arc at each side of the lobe. Doesn't it prevent a smooth action? Isn't it likely that this edge is going to get ground off by the time, increasing the gaps in the fit? I did browse through some images of cycloidal discs and most of them seem to have a smooth curve, though they might be approximations.
Some cycloids have these points, some don’t. If you simulate a continuous input rotation and a directly proportional slower rotation on the cycloidal disk, you can see that the point naturally follows the edge of the pin perfectly. No matter what position it’s in, the disk will never try to push through a pin. Additionally, load should be balanced on all of the lobes, so the points shouldn’t take any more strain. It’s quite the fascinating thing.
@@LeviJanssen Right, it definitely looks proper in motion. The thing is, or at least my vague idea is, that in the end it's supposed to transmit torque. So there will be forces on either side of the lobe pushing it against the pin (or vice versa). And there my concern is that even though the theoretical motion is ideal, with the torque it will have the tendency to smooth out that ridge. But it really could be a negligible effect - I was just curious about your insight in this. Did you by any chance see the recent installment by NYC CNC about cycloidal gear? ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-Eds48L4cJjM.html They share the gearbox file, but I have no idea what method they used to design their discs and/or whether they are theoretically correct like yours. They seem to avoid the ridges, though.
Hello Levi, the content is great on this channel. You got a new subscriber. How would you alter the dimensions for the tolerances of 3d printing? Do you simply use offset on the entire boundry of the cycloidal gear?
Hi, I don't think it's a 10:1 reduction ratio. Because you have 11 pins and therefore each revolution moves the cycloidal plate by one tooth. So you need to rotate the shaft 11 times to get the plate to the starting position.
You're wrong, its 10:1. Each time the disk moves one peg, 1/11th of a turn, the input shaft doesn't make a full rotation, it makes 10/11th of a rotation from the previous peg for that same tooth on the disk. That means every time the disk has moved around all 11 pins, one full revolution, the input shaft has rotated (10/11) * 11pins = 10 times. 10 turns of the input for 1 turn of the output = 10:1
Hey I am trying to follow this but when it comes to offsetting the splines, fusion won't let me select more than one spline. What am I doing wrong? great video BTW!
16:02 but still not get it.if all pin need contanct it allways. well there it is. do it. let it it spin and then boolean. it forms it? it will be perfect if it wobble correct ammount
Wouldn't it be better to use a proper gear-creation tool? The scientific reason for the shapes of the teeth in gears is that there is no friction. Your design will rub and heat/wear ...
