Servos vs Motors

[Dudekiller]

I have a question about motors. I know that every servo is configured differently (even if their the same brand and model), but are all motors of the same brand and model configured differently, or are they configured the same way?

[airman00]

motors have different characteristics - number of windings , max amperage, thickness of wire windings ,etc.

[Dudekiller]

Do you have to configure motors like you have to do with servos?

[airman00]

DC motors need special drivers called H bridges

[emmannuel]

Do you have to configure motors like you have to do with servos?

I am not sure what you mean by configure.

If you mean control, no they are controlled in different ways.
Servos are controlled through a signal, where as motors are controlled through an H-Bridge circuit.

Servos are in general easier to control, specially if what you want to do is stuff like turn the motor shaft at 0 to 180 degree angles.

[Webbot]

Servos can be controlled directly from your microcontroller. However - you may notice that they perform slightly differently. This could be because you haven't 'modified' them identically but also because each servo can have slightly different characteristics.

DC Motors - you need some kind of hardware to convert the microcontroller signals into something with enough power - a servo has this circuitry built in. For a DC Motor this is called an 'H bridge' or 'Motor Controller'. See my tutorial at http://www.societyofrobots.com/member_tutorials/node/159. The motors themselves don't need to be 'configured' as there is nothing to twiddle with.

Either way - if you expect your robot to follow a straight line - you will be disappointed as each motor/servo behaves differently. This is when you need 'encoders' to tell you how fast a motor/servo is 'actually' moving so that you can adjust the signals so that each motor is doing what you want.

[Dudekiller]

SSo what tools do I need to make sure my servos for my robot move perfectly straight?

[airman00]

SSo what tools do I need to make sure my servos for my robot move perfectly straight?

modified servos have speed control , so you adjust the speed by each of the motors until the robot drives straight

the only tools you'll need is a programmer and some patience 

[Webbot]

Yeah - but be carefull. You may adjust the servos so that at 'full speed' they go in a straight line. But drive them at 'half speed' and they may no longer go in a straight line. ie the response of the servos may not be exactly linear over theor range. But, hey, this may not be a problem unless you're trying to build a robot that needs to have a 'sense of position' (ie maze solving, path finding etc). If you do need this - then search this forum and tutorials for 'encoders'.

For your average 'fun bot' then this is overkill.

Good luck

[Dudekiller]

thx guys! You've been a great help!

[Dudekiller]

Sorry! I found this today! http://www.servocity.com/html/servo_synchronizer.html

Will this do the job? If so, then how do I program it using a PICAXE development board?

[Admin]

You don't program the synchronizer.

You plug in the single plug on the left into your PICAXE. Then all the other servos, that you want to do the *exact* same thing, go on the bottom right.