[protopete]

I got this Arduino bot for $70. Has its own battery for sufficient power. The motor gearing is a bit fast, so it's better to use PWM to slow down the motors, except the default pinout disables PWM on the drive gpios when the servo is enabled. The build quality is ok, except there are no spacers for the bolts between the PCBs and acrylic base, so I worry about damaging the PCB during assembly.

https://www.amazon.com/Elegoo-Four-wheel-Ultrasonic-Intellig...

[geppetto]

Li-ion battery is much better but I don't need an Arduino board nor sensors - we've plenty of - and I don't get the 4 motors design... more problems and no particular gains.

Al these kits and chassis look like a different mix of the same - not so good - parts.