Small, low-powered linear actuators?

[Roowilliams]

Hello,

I am looking for a small, low-powered linear actuator to be used as a bolt for an internal lock. Around 4mm stroke would be enough. Doesn't have to be too sturdy, was planning to use a really small solenoid and then learned that they need a lot of current!

Any recommendations? 

Cheers

- Andrew

[Adrian Godwin]

The stepper motors used to move the carriage in floppy disc drives are
quite low power. Would probably need simple drivers to run from an
arduino but nothing high-powered, and they have screw threads that can
be used to move a bolt mechanism.

-adrian

[Peter "Sci" Turpin]

There's some stepper-based actuators that show up on ebay for about £10
each. I've been tempted to try them, but they only have about a 12 or
25mm stroke. Asside from that, love the design. You'd probably want to
add a hardened pin to the end of the shaft though.

http://www.ebay.co.uk/itm/38031788284