Cycloidal Reducer 40:1

Mickey666Maus

Germany
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This is a WIP of a cycloidal gearbox with a reduction ratio of 40:1. It is driven by a Tarot 4108 brushless motor, in theory it should have almost zero backlash...

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#1  

Awsome. Looking forward to your progress on this. Do you know what your final torque will be when you on complete?

#2  

There is a lot of math behind it that I really do not understand. But I guess from kv value of your brushless motor, you can calculate the torque constant.

https://www.fxsolver.com/solve/

So the Tarot S 4108 should have a torque constant of 0.02512 Nm/A

Also you can calculate the revolutions per volt applied...  The Tarot S 4108 has 380 rpm/volt or 39.79(rad/sec)/volt There is an online converter for this! https://lucidar.me/en/unit-converter/rad-per-second-to-revolution-per-minute/

So once the gearbox is working I will need to measure the amps the motor draws under load, but lets consider 2.5Amps... 0.029 * 2.5 = 0.0628Nm

By multiplying a gear ratio of 40, the ideal torque on the output is 0.0628*40 = 2.512Nm

But I really don't know much about all this...so please if anyone here knows better correct me before I blow up the next Power Supply!!:D

#3  

Interesting I tried the Chinese to english translator but it didn't work.   WTF:p

#4  

Great job and that looks like mine. I have some bearings on order because I has to use ones that were 'closeish' on my first prototype. Interested to see how this goes. If you don't mind I will plop a few pics in this thread. Just an interesting side note here. I had a college prof ask me about how much torque a Newton meter is. I had no idea. He told me that a newton was equal to an apple. So imagine holding an apple on a 1 meter weightless stick. Remembered that all these years.

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Synthiam
#5  

Have you guys ever seen this from James Bruton? I’ve seen real commercial products of elastic actuators recently and they’re really great.

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Synthiam
#6   — Edited

Something like this can be 3d printed and use 2 springs. One on either side... I got it from this document: prismatic-sea-paine.pdf

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#7   — Edited

@Perry_S yes please!!!:D

Actually I thought, I'll just throw my actuator in this thread to start the discussion!!

I got it working now, but the vibration is really heavy...lets see if I can reduce it some more!

What were your issues?

I will put together some links for Cycloidal Gearboxes that I used to build mine...

Which CAD software are you using?

I will upload all the .stl files once I got that gearbox ready!:)

@DJSures that looks great!! I am also following quiet a few quadrupets, James Bruton has two versions that he is currently working on...seems like elastic actuators are a big deal, when it comes to building a walking robot!! Super interesting!!!

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Synthiam
#8  

Well - yes, walking robots can benefit from elastic actuators. However, I can see how they can be used for al joints and replace servo motors. I can envision a modular design that can replace a servo using an elastic actuator with a spring for the force measurement.