Hello Alexander
The shop cutting disc and
motor seem well dimensionned and a coherent set, so I just use 2. Furthermore, building a mechanically correct belt transmission is not so easy, as I do not have any machining possibility.
On the attached picture, you can see the 2 cutting discs arrangement which made a 42 cm cutting width. Having such a width with only 1 disc would oblige to build a big and heavy robot with a powerful
motor because of the inertia of such a disc, proportional to the square of its radius.
Seen from front the discs are turning toward the center. There is a few millimeters high difference between the 2 discs to avoid the blades to touch each other. The whole cutting system can shift to each side (see pictures), so it will be possible tu cut along a wall or around a tree slightly touching it without being stopped by the bumper and with neither damage for the mower nor for the wall or tree.
Anyway, as I have not finished to build it, this is just what is expected, I cannot tell if it mows correctly, not yet
Jacques
Attachment:
https://forum.ardumower.de/data/media/kunena/attachments/2809/UnderMower.jpg/
