The PIC16F88 has built in PWM. You can use that for the motor control.

What you may want to consider, is stepper motors. Stepper motors can be moved one "step" at at time, giving you greater control over your movements. You can also "micro-step" the motors to get even more control over your arm.

They are rated in holding-strength. That is how much weight they can hold still.

Yeah some friends told me same, but i need to use DC.

 

It is DC. What made you think otherwise?

 

1. Yeah at first without controller it worked perfectly. (used 5V for motors directly)

If motors are rated for 2.4 volts, and you ran them directly on 5, did they heat up at all??

B. Morse

 

Great pictures. As a wild guess- arm is operating at about 15 to 1 mechanical disadvantage, so lead screw needs to pull about 15 kg. If replacein motor try for 5 to 10 watt motor with 30:1 gear reductoin.

 

It is DC. What made you think otherwise?

you know what i mean. My project head just told me to do it.

If motors are rated for 2.4 volts, and you ran them directly on 5, did they heat up at all??

B. Morse

Nope they didin't

Great pictures. As a wild guess- arm is operating at about 15 to 1 mechanical disadvantage, so lead screw needs to pull about 15 kg. If replacein motor try for 5 to 10 watt motor with 30:1 gear reductoin.

Thank You i will consult about it :]

 

Darn so it's something new this time... i reassembled gears and tested again. So with +5V it works perfectly now... (without controller). And i tested it with controller... it didn't worked. So i measured. Motor eats 0.8A current without load, and i was shocked when i measured voltage, it was only 0.7-1V and why it's i don't know. i checked what's Vdrop of L298 and it's 1.8-3.8V when current is 1A and 4.9V when current is 2A. i don't get it why my motors can't get enough voltage :/