par glnc222 » Ven 1 Sep 2017 22:21
I gave that side brush mod to a German user. I do not think anyone else has tried it. The Vorwerk and Botvac brushes use a belt driven brush better than the small gear motor which can fit in the XV. More hardware for shaft coupling and altered interior of the case would be needed for a belt drive. F_Robot modified the case for putting in the gear motor a little differently. He is very skilled with epoxy etc., engineer, and rebuilds it anyway he wants. The belt drives might use a motor similar to the lidar. I never examined the Botvac motor.
The Vorwerk VR200 has the side brush in the front corner, maybe better. F_Robot thought they then miss furniture legs. They would seem to be better in corners.
An important point of adding a motor is that PWM rpm control is not available, and the motor can burn out if stalled from high current load if not protected, besides stopping the robot. So the polyfuse was used for this case. A motor control board could be made, but more work and expense. Motors sort of short out when stalled, with the coils engaged continuously instead of pulsed by the commutator. A brush looks like something which can be stalled by obstacles. There have been failures of Botvac brushes. The magnetic coupling can allow the brush to be separated in some severe incidents for safety, but then sometimes fall off to easily.
Note the motor drive current, which can be tapped on the vacuum fan line, comes on when the Test Mode is enabled over USB, for testing. Motors turn only under RPM control. When cleaning, the side brush goes on and off with the fan and other motors, as the robot switches on.
By tapping the Wall Sensor output the side brush can be turned on only when against a wall. I saw such control mentioned in some newer cheap robot specs, maybe the Xiaomi. The Botvac and Vorwerk run the side brush constantly.
The XV's are so old, it may be more attractive just to get a Botvac.
I do not like the side brushes myself, finding they wear out and even break against sharp edges of furniture, pull wires out from the wall, and do not clean carpets.
One Samsung model 9051 has the best side brushes, with bristles pointing down at the floor. Most Powerbots have no side brushes, more to my taste.
par 
