608 bearing version of Actuator
The thrust bearings replaced with the more common 608 bearing. Not most 608s aren't designed for thrust, some are. That said even if they aren't designed for thrust at least now you can print and use this with bearings you probably already have. Note deep groove 608s have a fair thrust rating. For example: http://www.vxb.com/page/bearings/PROD/kit8780
If you decide to use an M8 threaded rod for your leadscrew you'll need: http://www.thingiverse.com/thing:34826
Proof of concept video here: https://www.youtube.com/watch?v=Qap55vV6yhM