Linear motion from a motor

[duste83]

What is the best way in using a motor for linear motion and adding torque?  I need something simple and easy.  Any ideas would be greatly appreciated.

[Soeren]

Hi,

What is the best way in using a motor for linear motion and adding torque? 

That depends... What length should the move be, how fast, how much torque?

[duste83]

I am building a life sized R2-D2.  This is for the third (center) leg.  It will need to go about a foot in about 2-3 secounds and will need to hold most of the weight of the robot.  A great start for my first robot.

[Soeren]

[...] and will need to hold most of the weight of the robot.  A great start for my first robot.

A great start would be supplying the parameters needed:
So, 12", 2..3 seconds, ?N/m.
And what is it gonna weigh?

[nottoooily]

- threaded rod
- wire and pulleys
- crankshaft - needs to have a gearmotor that can't be reverse driven.
- pneumatic - how about a bicycle pump for a cylinder??

I like crankshaft best because if you don't mind some front/back angling of the leg you can do it without any moment-supporting sliding channels to guide the leg through.

But really the choice depends on loads of information that only you know. Certainly no single best way.

[duste83]

This is what I need.  Different ways of creating linear motion.  I've searched the internet several different ways and I'm still not coming up with something that would satisfy my imagination on how I'm going to do this.  Thanks for your input.  I will look into all of your suggestions.