Quote Originally Posted by Relentless
Today I stuck a standard 10mm screw thread into a slightly discharged 12v cordless drill, with a nut on the thread, turned it on and I pushed down on the nut with all of my force. It didn't even slow down one bit. I later measured how much force I was pushing down with, and it was 30kg (I'm 15, don't laugh!).

A drill and screw thread, say a 12v motor at 18v, standard m10 bolt and nut, you will have something that could compete with a commercially bought actuator, for next to nothing. If it was a 12v drill at nominal voltage and it didn't even slow down for 30kgs, I reckon it could quite comfortably lift in the order of 100kg at 18v.

Fraction of the price, rather more powerful. Just something to think about.
You are probably better off using something a bit more robust and also from experience with Cylon when it had this type of actuator from a Bosch 35W the bearings at each end need to be good because the play is a real issue in terms of reliability.

That said when you buy a rover seat for the Bosch 35W motors you gets an abundance of really useful tried and tested linear actuators.

Andy