hexapod motors

[benji]

hey guys , actually in trying to make a hexapod i should use servo pwms but the problem is that i cant get them ..
someone told me why not use steppers ,as long as i have 12 ones, but still im not sure about the TORQUE ,,,, i read that the servo most hexapods use is with a torque of 3kg.cm
i checked some steppers and it is no more than 10 gF.cm holding torque ,,,im not sure if i can use a stepper....
latley i was thinking why not use dc motor,,and make it rotate half rotation, since that what i need only in the hexapod walk,,is there some way to break the dc motor after one half rotation?
i read a litl about the L298n,, still not sure,,,,help

[Admin]

You definitely want to be using servos for this.

i should use servo pwms but the problem is that i cant get them ..

Tell us about your setup/microcontroller and we will help you out.

[Ro-Bot-X]

Check this message: http://www.societyofrobots.com/robotforum/index.php?topic=2183.msg14598#msg14598

[Fredrik Andersson]

Yes, no question about it. You should use servos.

http://www.lynxmotion.com/Category.aspx?CategoryID=3

Read about these hexapods, it might give you some ideas.
You need pretty much power for a hexapod. I think you should go for at least 76oz-in. It's the minimum requirements at Lynxmotion and they sure know their thing.

[benji]

Tell us about your setup/microcontroller and we will help you out.

sorry i meant i cant get the pwm servos, not the pwms ,,by the way im using the atmega128 .

Check this message: http://www.societyofrobots.com/robotforum/index.php?topic=2183.msg14598#msg14598

yea i did check this earlier but i dont know how to break the dc motor at exactly 180 degrees .

You need pretty much power for a hexapod. I think you should go for at least 76oz-in.

the whole hexapod im tryin to build is 2.5 kg as weight . its alaminium. does it really need that 76oz-in

[Fredrik Andersson]

Tell us about your setup/microcontroller and we will help you out.

sorry i meant i cant get the pwm servos, not the pwms ,,by the way im using the atmega128 .

Check this message: http://www.societyofrobots.com/robotforum/index.php?topic=2183.msg14598#msg14598

yea i did check this earlier but i dont know how to break the dc motor at exactly 180 degrees .

You need pretty much power for a hexapod. I think you should go for at least 76oz-in.

the whole hexapod im tryin to build is 2.5 kg as weight . its alaminium. does it really need that 76oz-in

Have you checked the internet? I am pretty sure they sell servos out there somewhere.

2.5 kg, that's pretty much i think... is it with or without batteries?

Ah, just noticed you are using only 2DoF legs, so you could probably go easier on the torque then, but as your robot weight 2.5 kilos i really think you should go for the 76 oz-in ones.