Quote Originally Posted by daliad100
Quote Originally Posted by Metal Demons
You want me to buy an actuator, take a hammer drill and some how use the hammer drill motor to power the actuator? And, even if this is what you suggest I do, please could you give me some tips on how to achieve it?
To answer your question, what was meant by using a hammer drill was to remove the motor (and gearbox) and coupling this to a threaded rod. A nut on this threaded rod will travel up and down it when the motor is turned on.

If you look at a nut and bolt being tightened or the insides of a glue stick (a twist one) then you should see what I mean properly. However, for it to work you will need to make sure that only the nut or rod is turning.

http://robowars.org/teams/rotwang/blade/

Take a look at some of these pictures. They contain the same mechanism as above.

Finally, wikipedia is your friend the animation should help if you still don't get it

http://en.wikipedia.org/wiki/Linear_actuator
Yeah, that's pretty much it. Use the guts of an existing linear actuator combined with a bigger motor in order to give you more speed and lifting force - I'd say pick up a lower ratio (high speed) actuator and just put the new motor on it, junking the attached gearbox. I suggested the cordless hammerdrill motor as they're relatively powerful and commonly used in robots - a Speed 900 or something would be ideal too.