Friday, October 9, 2015

Walking "Humanoid" Robot found on eBay part 3 with 9, 13, and 17 DOF

After not having a lot of success with a more complex robot I went backwards and built a 9 DOF humanoid robot.  Here is a picture of that robot.

Here is the video of him walking.


Up next is the 13 DOF humanoid robot.

Here is his video.


Here is his servo array to make him walk forward.

int walkf[6][6] = {
// 0    1    2    3    4    5
{ 80,  80,  80,  85,  90,  90}, // Left Ankle
{ 90,  80,  70,  70,  70,  80}, // Knee
{ 90,  80,  70,  70,  70,  80}, // Hip
{100, 100, 100,  95,  90,  85}, // Right Ankle
{ 90,  90,  80,  70,  70,  80}, // Knee
{ 90,  90,  80,  70,  70,  80}, // Hip
};

I still cannot get a 17 DOF robot to work very well.  My servos are too weak for the weight! Do not buy the MG995 or MG945 servos except for the arms (or for a 9-13 DOF robot). I have burned some up trying to power the 17DOF robots legs. I am thinking of trying the MG958. Anyone know if that servo has enough power?

Here is some more Information that I have discovered about servos and robots.

Be sure the servo that you buy is not a cheap imitation.  This can be detected by the seller hiding the manufacturer name or misspelling the manufacturer name.  A common example would be “Tower Pro” (real) or “Towerd Pro” (fake).

This is my new rule of thumb for making humanoid, as in 2 legged robots.  The problem is that the more the servos (and their connecting hardware) the more the robot weighs. 

The leg servos of a 5-9 DOF Humanoid robot should handle 100 oz. inches of torque. 
The leg servos of a 10-15 DOF Humanoid robot should handle 150 oz. inches of torque.
The leg servos of a 16-20 DOF Humanoid robot should handle 200 oz. inches of torque.
Here is the video of the 17 DOF humanoid robot.


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