[cyanf]

For legged, you want high torque and backdriveability (for shock absorption).

Agricultural drone motors like the eaglepower 8308 are ideal.

They’re cost effective, (~$80 from aliexpress) & you can pair them with a 3d printed cycloidal drive to fulfill both requirements.

Industry actuators are an order of magnitude more expensive than this.

Extra: If you go down this path, you’ll need a driver. The Xdrive is frequently recommended, but there’s a clone that’s significantly cheaper: https://makerbase3d.com/product/makerbase-xdrive-mini-high-p...

[lastdong]

This is pretty cool, thanks for sharing. I wish there was a (mostly) 3d printable Cara mini, but I’ll start with Cara.

[regularfry]

The layout is doable with hobby servos, but you'd need to patch in current sensing for that bit of the feedback. It's not terribly difficult conceptually but it's an extra complication that most servo power distribution boards don't give you.

You can also strap a capstan to the servo axle, if that's your thing. I've prototyped that myself in the past. You can go surprisingly far with an FDM printer, an SG90, and some dyneema bowstring. One thing I haven't tried is modding one for continuout rotation to get around the way the capstan drive limits the output angle you can achieve - I was happy reducing from ~180deg to ~45deg for what I was doing - but that's relatively well-trodden ground. Might pull that project out of the storage box it's languishing in at some point.

[Animats]

> The layout is doable with hobby servos

Mostly we're past that. Robotics with hobby servos sucks. Been there, done that, robot arm is in electronics recycling bin right now.

[regularfry]

I agree it's not great but for scale and convenience it's good. If this was going to just get scaled down, what motors would you pick?

[cyanf]

Motor: https://www.aliexpress.us/item/3256804897857573.html?gateway...

The 90KV version is what you want.

[JKCalhoun]

"The 90KV version is what you want."

You mean the "KV90 color" of course, ha ha.

That we live in an age where "agricultural drone" is even a word pairing…

[coolvision]

thanks for the Xdrive pointer, I just got samples of tinymovr and odrive controllers (with FOC), they seem nice but are more expensive.