Thanks a lot for your response the battery have a flat head and I think it was not correctly in contact nyble now walk a little bit but I have not yet screw the part so I will try to recalibrate screw it and make a new test I will let you know it was good :)

Thanks, when I send "kwkF" the cat perform well a periodic walking pattern but when I put it on the desk nybble do not walk video And when I turn on the gyro the motion decelerate Unfortunately, I can't measure the voltage of the batterie I don't have a Multimeter

Hello, yes when I hold nybble in the air legs can move. this is the battery photo: