ROBOTICS | Measuring repeatability of a strain wave gear from Harmonic Drive

A high gear ratio with no backlash in a very compact size - is what makes the strain wave gear a key component for precision industrial robots. The strain wave transmission (also known as a harmonic drive) was invented in the fifties and has not changed since then. Moreover, it's difficult to find better alternatives to this day. Thanks to the strain wave gears, industrial robots are known to be extremely repeatable. The repeatability of modern industrial robots can reach a few micrometers over thousands of cyclic operations. For comparison, a human red blood cell has a diameter of approximately 5-10 micrometers. As an example, this video shows the repeatability test of a single-axis robot that uses the strain wave gear from ‪@HarmonicDriveLLC‬. The measured repeatability is less than 1 micrometer (0.001 mm).
Special thanks to ‪@tinymovr‬ for developing a compact high-performance BLDC controller.
Instagram: / olekstepanenko
• Project idea
• Design
• Programming
• Filming
• Music
by Oleksandr Stepanenko
#robotics #precision #automation
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Created by Oleksandr Stepanenko
CZcams: / oleksandrstepanenko
LinkedIn: / olekstepanenko
Instagram: / olekstepanenko
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[@FlashDrive356]

It's insane how precise motors can be these days. Great work as usual!

[@OleksandrStepanenko]

Thanks!

[@stevenmcculloch5727]

The lighting is so good it looks like like a render

[@OleksandrStepanenko]

Thank you!

[@gatoninja4387]

is un model 3d???

[@stevenguevara3252]

Lmao for real… almost feels like it is.
😂

[@williamluong7743]

I don't think it's the lighting, I think it just looks too perfect lol

[@navid9852]

Great demonstration. The music is pretty synched!

[@OleksandrStepanenko]

Thanks!

[@williamforbes6919]

This video is a phenomenal demonstration

[@OleksandrStepanenko]

Thank you so much, Matthew!

[@tooba6290]

Accidentally read it as phenomenal destruction 😬😂

[@lucianolizana446]

impresive

[@OleksandrStepanenko]

Thanks!

[@evanbarnes9984]

I just realized the indicator is reading micrometers rather than thousands of an inch, and my mind was even more fully exploded

[@OleksandrStepanenko]

Yes, that's truly mind-blowing precision!

[@tinymovr]

Amazing work as usual!

[@OleksandrStepanenko]

Thank you so much!!! 😊

[@abdullahcakan]

eXcellent !!

[@OriginalJetForMe]

Wow!!

[@lordmemester8798]

i can't stop watching the last 8 seconds of the video

[@OleksandrStepanenko]

It really looks pretty good, thanks for sharing!

[@kentvandervelden]

Maximum overshoot vs approach speed could demonstrate stiffness. Doesn't isolate the gear though.

[@DianiAmine]

Nice work, and your video is epic

[@OleksandrStepanenko]

Thank you, Diani!

[@Scrogan]

Now come at the same location from the opposite direction so we can see the backlash! I imagine these gearboxes can have really low backlash, but seeing is believing.
The other critical thing is how heavy they wear.

[@MrRedBuilder]

Being a harmonic drive, they have nearly none. With how they are built, the rotor attached to the motor actually completely locks the output in place

[@valdaszs]

Just load end effector with compression and tension spring and you see all beauty :)

[@Derpuwolf]

Impressive stuff here.

[@OleksandrStepanenko]

Thanks!

[@jnn01972]

Maybe you can expand on how is the motor controlled with a computer/microcontroller...

[@anthonywalker6168]

With a mechanical efficiency sub 90%, that’s their downfall in becoming the way, as opposed to an option amongst many.

[@user-hg8qg1nb3o]

amazing

[@OleksandrStepanenko]

Thanks!

[@jakobholzner]

just gorgeous

[@OleksandrStepanenko]

Thank you, Jakob!

[@dashs2597]

Definitely have to experiment more with harmonic drives. What did you think about cycloidal drives?

[@OleksandrStepanenko]

Never tried it, but I have a feeling that the strain wave gear is the only way to go...

[@cry-wr4wt]

Jokes on you 'cause that micrometer doesn't go below 0 :D
Jk, love your videos

[@OleksandrStepanenko]

Thanks!

[@SusumoKakinotane]

What are the tech specs of the motor? do you have a link?

[@devanshgarg31]

His videos are so Professional!!

[@OleksandrStepanenko]

Thank you, Devansh!

[@i-make-robots]

what's the model number of the strain wave gearbox?

[@leonordin3052]

If only u did the other direction as well. Going into minus then back, stop at zero and to the start. For backlash measurment.

[@OleksandrStepanenko]

there is no backlash by design:)

[@leonordin3052]

How do you guys make these parts so good then. Is it lathe work mainly? ​@@OleksandrStepanenko

[@OleksandrStepanenko]

@@leonordin3052 those are Japanese gearheads, these guys know how to make them right:)

[@smd9600]

What types of motors are used ????

[@OleksandrStepanenko]

BLDC

[@localhawk1]

Gravity might help here a litte bit ;). A confirmation on a vertical position would be interesting.

[@capnthepeafarmer]

I can't remember, but are harmonic drives backlash free?

[@OleksandrStepanenko]

Yes

[@ponlokhom6863]

what type of motor do you use? Sir

[@OleksandrStepanenko]

bldc

[@gerryakbar]

But how about the gauge's repeatability

[@hillstudios]

way more repeatable than the motor

[@shroomatic]

OMG.

[@gatoninja4387]

hooooo presicion imposible

[@santiagosalinasuy]

ok

[@Chris-bg8mk]

Microns?

[@OleksandrStepanenko]

Yes.