DIY Actuator for quadruped robot based on a ballscrew: Powerful!

We build and test a powerful robotic actuator based on a ballscrew, a brushless motor, an ODrive board and a magnetic encoder

[glasslinger]

The spring in the test fouls the accuracy of the measurement. The arm must LIFT the weights!

[LautaroOrdenes]

"Fabulous video, it's great to know that there's someone opening up this knowledge to the public."

[freakinccdevilleiv]

Excellent. You should have a lot more views.

[whitneydesignlabs]

Super cool. Do you intend to post any plans, drawings, or parts lists? This would be fun to recreate. It seems like this actuator could be strong and fast. Also the design seems like could be adapted to bipedal robots as legs or arms. Seems like it would be fast enough to handle balancing operations.

[dekutree]

Assuming that motor is similar to the one I tried, you can replace the bottom 8x22mm bearing with 10x22mm and stick the machined end of the ballscrew up into the motor so it's turned directly instead of needing all that coupler business.

[alttabby]

Great video! Are you going to share the 3d print files?

[amoghjain]

amazing job! thank youuuu for such a detailed explanation! learned a lot of new things 🙂

[Unmannedair]

It's a clean design. not how I would have designed it, but I'm curious to see how it works out. I suspect that you're going to have some difficulties when it comes to tuning the balancing over uneven terrain.

[dinoscheidt]

Crazy that it is back drivable…. Impressive

[mikegLXIVMM]

It looks well designed and robust.
Thanks for posting!

[abhinavt]

Very nicely explained. Thank you for this video.
I would like to learn more about this design. Is there a technical term for this actuator design? What terms can I use to search on Google?
Thanks in advance!

[critical_always]

Back-seat driver here. Looks like a great design. The only thing causing me to raise my eyebrows was the thin plate motor mount.

[jimj]

This must be perfect for a humanoid robot!

[jorgennorberg]

You use a 1 700W motor for each joint?

[SuperHaptics]

Awesome i like it. But the use of slotted screws should earn you some jail time 😂.

[H...]

Maybe I'm missing something, but the way you used that axial bearing confuses me. At best it only takes up load in one direction, in the other the motor bearings take all the load. But I can't see what the axial bearing is transferring the load to even in it's working direction if that aluminium bearing block is not fixed to the tube rigidly. Other notes, steel ball bearings on aluminium tube will wear and marr up the aluminium quite quickly, especially since the ball bearing can't actually roll against both at the same time, it will slip against one of them.There are off the shelf POM coated rollers that play nice with aluminium though.

[tadashi_hamada]

The actuator seems pretty noisy. Is it coming from the ball screw?

[makerslife]

Maybe extend the knee joint through the back and add a gas piston to give some assist.

[davef]

Solid and straight forward, good stuff. What's the cost per leg if you don't mind me asking?

[rodrigoruiz]

Nice!! which brushless motor are you using?