Time to ask for some advice again lol !!!

I have been playing with my linear actuator trying to get it to extend/retract as quick as possible. So far I have managed to get it upto 45mm/sec (measured approx).
But this is still not fast enough for my needs, so any advice would be appreciated.
I don't really want to go to pneumatics at the moment as don't have enough knowledge (safety).

Thanks