View Full Version : hoap 2 leg configeration

07-12-2008, 02:15 PM

I was trying to download a pic of the leg configeration but the pic is in the wrong format. Anyways, they use a rubber band attched to the hip to a servo at the knee to control the hip and a band at the knee to the foot connects to the servo in the knee to move the foot.

I would like to know if anyone is familiar with this method and if there is any real benefit from it. I would assume that instead of a servo they might be using a stepper motor.

Here is a link to the intruction manual for the HOAP-2


If you goto page 75 it shows a few good pics on how the HOAP-2 legs are set up.

As a side note these robots sell for almost $50,000 USD and they do not seem all that advanced to me. With some modifications I am sure a Robonova can preform many of the same tasks.


07-13-2008, 10:44 AM
Those are timing belts though, not rubber bands. Looks to me like they use this configuration so they can put the motors on a different location than the actual joint, which would be an advantage if you want to have eg two joints perpendicular to each other without losing all the space the motor takes.

I think the price tag is mostly due to the materials used. Agreed, there's a lot of aluminium plate such as in the robonova or an SES system bot, but there are also quite a few milled parts visible in the pics.

Still a whole lot of money though..

07-13-2008, 01:09 PM
i looked at the intruction manual you uploaded and thats a nice robot. ive never seen it. where can you buy it

07-13-2008, 01:16 PM
i was thinking and the only thing i can see that would make this robot so expensive might be that when i looked at the servos they looked like the nicest servoes ive ever seen. they probably out perform my bioloid servos by far. i wonder if they say the torque on those things in the book. plus i noticed that they also talk about the intelligence of the robot. so im assuming that it probably has a lot of nice software in it letting you program it probably something like asimo if i had to guess. but i would guess a robot like that to cost about 5000 usa dollars. haha no 50,000. if i put 49,000 dollars into my bioloid it would be far better that this robot.

07-16-2008, 01:58 PM
That is just plain awesome.

*Begins to reverse engineer the damn thing in his head*