Homemade biped robot

[jeffmorris]

I built a biped robot but I found out that the servos that came with the EZ-Robot kit are not strong enough. The hip servos can't lift the legs up. Any suggestions for stronger servos?

[RPCoyle]

The EZ-Robot kit web site advertizes a Heavy Duty Servo... you might try that. I'm not sure what servos are used in the kit.

[Funky Diver]

http://www.servocity.com/

Those guys are pretty switched on, and will ave anything you might need.

[packocrayons]

Servocity would be the best choice.
If you're cheap, go to hobbyking.com, they have plenty of servos at cheap prices (10Kg/cm for 5$)

[jeffmorris]

I connected my homemade biped robot to Arduino UNO board and it worked better than when connected to EZ-Robot board.

[oric_dan]

You didn't mention what the servos are, and the ez-robot site only says standard servos.

http://www.ez-robot.com/Shop/

Likely those are just the plain old 44 oz-in servos, which really don't have enough torque for
most walkers, except maybe a small hexapod where the load is shared between 6 servos at
a time. You need servos with maybe 5X the torque for a biped.

I would go to the lynxmotion.com site and see what they are using on their walkers.

[jeffmorris]

I replaced the servos that came with the EZ-Robot kit with HD servos from Polou. I thought that the EZ-Board was bad but I found out that it worked better on my newer home computer than my older computer at the program for mentally handicapped people.

[jeffmorris]

I put "roller skate" wheels on the biped robot. How do I have the wheels turn in one direction only? The wheels are not connected to motors. The wheels came from Lego Technics building sets.

[packocrayons]

What do you mean by one direction only? Unless you reverse the polarity (assuming it's not PWM controlled), they should never turn the other way.

[jeffmorris]

I need one-way clutch or similar device to have the wheels roll forwards only. My robot moves its legs back and forth. The wheels should lock when the legs move backwards.

[packocrayons]

Google one way bearing, without looking at the robot it would be hard to show you exactly how to use them, but it should make sense.

[oric_dan]

I should think a little mechanical foot/stop would be easiest, mounted behind the wheel so it
comes down and binds the floor when the foot moves backwards, but slides freely when the foot
goes forwards.