demestav

Hello. I am doing a project which a part of it is about controlling small robots. I am at the point where i am looking for components, actually the motors.

Questions:

(1) for the movement of the whole robot, the most appropriate (i think) is a dc motor. No greate accuracy needed just power, forward and reverse. Does anyone know where to buy small dc motors in UK? I looked RS electronics but i cant find any. (small and cheap)

(2) What are the appropriate motors to use for simple movements on the robots. For example moving a small arm. I am a bit confused between servo and stepper motors.

Please keep in mind that the robots will be contructed using LEGO parts and will be approx. 15-25cm long.

Thank you for reading.

Nigel Goodwin

RS Components do some cheap model makers motors, they also do VERY expensive professional motors!.

A servo (usually) only turns a limited number of degrees, but it does this as an absolute position - i.e. you tell it a position to go to, and it goes there. Because it's a geared DC motor, it's small and powerful.

A stepper motor only provides relative positioning, you can tell it to move a number of steps from it's current position, either clockwise or anti-clockwise, but you have no way of knowing where it was in the first place. Steppers are generally expensive and fairly low powered - as they aren't normally geared.

If you're using Lego parts, why not use the Lego motors?.

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demestav

hello nigel and thnx for the reply.

That is because LEGO motors are very very overpriced ( in my opinion ).

Nigel Goodwin

All lego parts are 8)

As far as the motors go, the ease of use will help to compensate for the cost.

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PIC programmer software, and PIC Tutorials at:
http://www.winpicprog.co.uk

Juglenaut

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