The latest bleeding edge build lets you make gearboxes with as much reduction as you can make the space for. 1000:1 should be no problem if you stack three 10:1 gear sets.
I've been a tad nervous about the idea of trying the bleeding edge builds for the sake of my large number of robots, but I'll back them up and have a go.
Fair enough! It is probably worth following the RR2 thread on GTM to see if anyone is having problems with each bleeding edge build before trying it.
I've tried it, putting the forks on two gearboxes. The first at 10-0.1 and the second at 10-0.5. The forks move at the right speed, but they're completely useless.
If I try to lift them with any weight on them, they just go limp and fall back to the floor after about half a second.