Life-size (?) Humanoid Robot for about $3000. ??????

[Thomas Messerschmidt]

I just saw this robot biped humanoid life-size(?) robot on AliExpress for about $3K, shipping directly from China. (Alan, I don't think you would be interested, though.)

"Biped humanoid robot AI intelligent machine human robot dog reinforcement learning training embodied intelligent millet motor"

A "millet" motor? I've never heard of one of those. 

Unfortunately, there are no real specifications, only a few really bad photos. I'm not sure how tall it is. Below is the link

https://www.aliexpress.us/item/3256809253994751.html

Anyway, you can get it in about a week. Still, I'm not sure if it can deliver what it (doesn't?) promise. I'm going to see if I am able to contact the seller for more info. I don't have $3K to spare though, so I will pass on it. 

Thomas

[Chris Albertson]

It's a biped walking robot, not quite humanoid, but still, it seems to stand and walk on two legs.

I count six degrees of freedom. 6 motors for $3,000 seems about right, given the speed and power required for walking.  You just can ot do it with servoes or cheaper motors

This looks to be about the lowest cost biped possible, ideal for someone who wants to learn about walking on two legs.

That said, we don’t know anything at all about the company except that they are quite unskilled when it comes to writing product descriptions.

The round ball-like feet mean that it does not need to have ankles.    It also lacks arms, which means it can’t do much more than walk, good for someone who only wants to study walking.

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[Thomas Messerschmidt]

I found another vendor selling the same item. There’s a video posted on this listing. Apparently the robot is about 31 inches tall. 

https://a.aliexpress.com/_m0T4JJX

Thomas

On Aug 15, 2025, at 1:33 PM, Chris Albertson <alberts...@gmail.com> wrote:

It's a biped walking robot, not quite humanoid, but still, it seems to stand and walk on two legs.

[Chris Albertson]

What you have here is one half of the typical robo-dog.     Robo dogs all have a 2-axis shoulder and a 1-axis knee.  The 3-DOF design allows them to place their foot anywhere in (x,y,z) space, but not able to control the orientation of the foot.   So they all use ball-feet, because spheres are the same at any rotation angle.

If you think about the kinematics, the two shoulder motors control the direction vector from the shoulder to the center of the foot.  The knees control the length of that vector.    Motion is easy to control if you think in terms of a spherical coordinate system.    The innovation here is applying this to bipedal walking, balance is harder than. with flat feet and ankles, but the cost is greatly reduced and the software is simpler.

So what you have here is a dog walking on two feet.   In theory, it should cost about half what a similarly performing dog costs.

But what would anyone do with this thing, except for walking research?

[Thomas Messerschmidt]

good point