servo motor for a quad robots (4x4)

Forum 2005-2010 (read only) Hardware Interfacing
1

Hi,
I would like to create a robot quad with 4 independent wheels.
I would like to get something like this but less expensive ::slight_smile:
http://cswww.essex.ac.uk/staff/lucas/roborace/roborace.html

I try to find a continuous rotation servomotor. I only find this one:
http://www.active-robots.com/products/motorsandwheels/servo-motors.shtml. The others Hitec, futaba need to be modified for the 360 rotation :-/

  1. Do you think these servomotors are enough to bring a laptop on the quad ?
  2. How many servomotor like this, I can control with the arduino ?? 13 ??
  3. I would like as know the difference a servomotor and a digital servomotor ? Is it the same connection with the arduino?
  4. Pwm is for dc motor ?

Promise, I sent you some pictures of the quad when is finished...

2

hi

Hi,
I try to find a continuous rotation servomotor. I only find this one:
http://www.active-robots.com/products/motorsandwheels/servo-motors.shtml. The others Hitec, futaba need to be modified for the 360 rotation :-/

Modifying servos for continuous rotation is easy. Check around on the net, there are lots of pages.

  1. Do you think these servomotors are enough to bring a laptop on the quad ?

Probably not. You'll have to carry the laptop and a big battery for the servos too.

  1. How many servomotor like this, I can control with the arduino ?? 13 ??

There is a library in the Playground ( for the Atmega8) that lets you control many, i think up to 10.

  1. I would like as know the difference a servomotor and a digital servomotor ? Is it the same connection with the arduino?

for R/C servos, there's no difference.

  1. Pwm is for dc motor ?

PWM is a series of pulses in varying widths. R/C servos use PWM at a set frequency to control the servo position. You could also send PWM from an Arduino to control a motor driver chip like the L298.

D

3

I started to make a diagram for my quad robot. I am not an expert. So, I would like to know, if there is a problem in my diagram. Do you think the 6v battery is enough for the 5 servos and the arduino ? Also, I don't know if I need resistances.

The diagram:
http://www.irit.fr/~Nicolas.Lassabe/diagram.jpg

The page of my quad robot:
http://www.irit.fr/~Nicolas.Lassabe/robot.php