LawnBot (unfinished)

Synchro drive bot that was supposed to mow the lawn for me. A small part of that at least.
Only LEGO® standard parts were used. Spring suspended wheel platforms.

Platforms are connected by chain. RCX and motor components are missing
completely:

ZNAP parts were used for the frame and as sliding bearings for the platforms.
I wouldn't do the frame again this way. The VacBot's frame is much stronger. I didn't
want to repeat that though (VacBot was first).

There was no way to construct a linear bearing of this small size other than using
the ZNAP parts. There are four sliding bearings per wheel platform:

A propeller was supposed to mow. It is driven by two old (and fast) technic motors.
The transmission ratio can be seen in the pic, the prop shaft carries the smallest
gear available. It was really fast. I never tried it on grass though. Three identical
wheel platforms with differential to make in-place turning possible. There are better
wheels for a lawn mower but I had these anyway:

Working suspension. Chassis is pushed back up by a large shock absorber which - at the same time - acts
as the drive shaft. This is how the motor power is transferred over variable distance in a tight space.
See VacBot for explanation on differential and general difficulties with a two-wheeled synchro platform.
ZNAP linear bearings. Suspension travel is limited by the shock absorber. The frame almost touches the wheel:

Spring travel must be linear. With a swing arm for ex. the wheels would be moved off center. That would
make it impossible to turn on the spot. I tried several parallelogram versions but couldn't find a version
that would actually work in that small space.