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20:1 Precision Compound Planetary

by Gear_Down_For_What Nov 23, 2018
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Hi, It is very impressive its back drivability with this high reduction ratio. I have question here what is the key to make it back drivable? I have printed out your model, but it only can back drive sometimes, not always as your video.

the second question is from the listed material, there is second sun gear, but I didn't see it from you CAD model? Thanks.

Happy Holidays!

So for back driving, you need it to be efficient, to make it more efficient you must spin It under load for a while, that will wear in the proper clearances to achieve the efficiency that you need for it to be back drivable.

as for the second sun gear, it's not there because its not really needed, it's just an idler, and in this case the gear set has bearings. so I left it out. if you wanted to, you could make room for it and add it in there.

Comments deleted.

Thanks for response. I did running the gear for a while before Christmas.Understood about the sun gear, actually now I found it can back driven. I guess after a while printing material stress is released but it has a little backlash too. is this material related?

Are these gear designed with tooth shift factors?

And have you tried higher ratio like 50:1?100:1?

Love this design! Any chance of plans for a single stage "non-compound" version?

I should really do that. It wouldn’t be that hard actually I could just chop a stage out of the existing fusion project.

Thanks for the reply! Yea that would definitely be awesome and open up the project for more applications. I'd modify the gear set myself but my knowledge of planetary gear design is still limited, ( the tutorial you made on YouTube is fantastic by the way), and it would be cool to have something to prototype with that I know works because you designed it XD. - Cheers!

In the video, we can see you adding some balls inside. Do you have the spec ? diameter ?

Thanks, and gratz for the great works !

I guess times have changed -- these bearings are much cheaper than I expected. Good to know I might not have to limit myself to 608's anymore. This really opens up a lot of possibilities.

Now I just need to find that keyhole saw that cuts easily through steel... What do they call it? A jump cut saw?

Should i add a Sheetrock saw, camera, video editing program, and precut shaft to the parts list?

What would one use this for?

robotics most likely