I did it (but my way....
http://www.iceinspace.com.au/forum/s...ad.php?t=43823).
The outcome was smaller PE (by almost 50% smaller) and reduced backlash, but noisier motors (because original gearbox uses plastic helicoidal gear on motor shaft, and mine is brass spur gear.. maybe I needed to apply gooier lubricant here).
Right now I am planning another one, basically I want to get rid of transfer 47-teeth gears (they are adding too much high frequency noise to overall PE) and replacing them with timing belts, and I want all this to be inside the mount (perhaps outside belts are quite OK as per Avandonk's mount but I do not want them exposed to un-intentional abuse).
All this will eventually pave the way to good and reliable guiding, planned for sometimes later.