@Danger! Thanks for the pictures of the waist mechanism. It gave me some ideas

@robotmaker

I like your RAD 4.0 robot. He's cool! I would like to use this kind of setup for my robot arm. Would you be willing to sell me a h-bridge rated for 30 amps connected to a FUTABA S3003 BOARD so I can control my dc gear motor like a servo? I would like to test one first then if it works out I would buy more from you.

here is one rated at 30 amps ,there are others 30 amp h-bridge i know i have one somewhere for a lower price

here is one cheaper rated at 30 amps

low cost 30 amp h bridge

and dual 50 amp bridge

dual 50 amp h bridge

I mean do you have an H-Bridge already connected to a FUTABA S3003 Board that I could buy that is ready to hook up to a motor?

Also, does it have to be a FUTABA S3003 or can any servo work?

most use t he futaba S3003 because it has schematic for it and pins easy to connect mine are in robots

I'm.going.to come back.and read this after I've had sleep. I have the wrist motors and claws and maybe a shoulder that runs off 3 to 6v motors I need to interface with ezb.

they will work perfect with FUTABA 3003 servo,and istead of the feedback pot can use two 2.6 k or 2.4 k resistors in series and use the center or use a trim pot and adjust the pulse width,in my design looking to use a servo motor way you asdust it is set it for 1.5ms and adujst pot till motors dont move,mostly near center value of pot witch is 2.5 k ,same with 2 resistors 5.2k divided by 2 = 2.6k or using 2.4 k 's mostle need to stay near 5k value when selecting two same resistors ,another name its called is 'dead center"