Compact WiFi/BLE enabled 4WD robot platform

A very compact 4WD robot platform which can be controlled with WiFi or Bluetooth using the smartphone or any else WiFi/BLE enabled device. The description of the entire electronic as the assembly instructions are on https://hackaday.io/project/25430-mini-wifible-4wd-robot-platform. (Please visit the site)
The robot platform mechanics is entirely 3D printed with the exception of the axles, the ball bearings and of course the nuts and bolts. All the gear in printed as m=1 with a fish bone structure for a self-fixing arrangement. The wheels are printed with a dual extrusion printer, the “tries with a soft” PLA and the inner part with ABS. With its 3:1 transition the robot is pretty fast but doesn’t finds any grip with all ABS printed wheels.