Floor cleaner - part 2

A somewhat underwhelming result from a few days of designing the drive chain for the dust rollers. Gears that roll nicely when held together in your hands behave completely different when driven in their final location.

The main problems appear to be:
1 - Gears twisting because they are supported only on one side.
2 - Screws do not properly align parts as I assume the thread digs into the hole sides asymmetrically.
3 - A lack of rigidity holding the gear train in place. A millimetre makes the difference between gears slipping and them moving smoothly.

So back to the design phase. Not sure if my printed gears will work - they look like they could do the job. The next iteration should tell.