Floating Work Plate:
No I have not really worked out all the details on this, but ...
Rather than putting the work plate up on springs and bolts, why not use gravity? Hang the work plate below the mid plate. No crazy 900 lb springs. Gravity is fairly reliable. Suspend the work plate on three screws. Tweak them as needed to do first order leveling.
I suspect the sunken work plate idea will be a bit less popular with hot ends that have fans on them ....
Bearings on drive shafts:
The nutty metric dimensioned 3/4" bearings fit ok on the shafts. They have less radial play than the nuts. With something thin, you could shim them to be a tight fit.
No I have not really worked out all the details on this, but ...
Rather than putting the work plate up on springs and bolts, why not use gravity? Hang the work plate below the mid plate. No crazy 900 lb springs. Gravity is fairly reliable. Suspend the work plate on three screws. Tweak them as needed to do first order leveling.
I suspect the sunken work plate idea will be a bit less popular with hot ends that have fans on them ....
Bearings on drive shafts:
The nutty metric dimensioned 3/4" bearings fit ok on the shafts. They have less radial play than the nuts. With something thin, you could shim them to be a tight fit.