Tutorial 6 Car + P-ROB3 Arm Project: Kid Grade Self-Learner Needs Help After After a Week of Trying

[zbn4]

Hi everyone, I’m an 8th-grade student teaching myself Webots. I’m stuck on Tutorial 6 where a small car and a P-ROB3 arm should work together. I dragged the whole P-ROB3 into the car’s children and turned OFF physics (no boundingObject) on every arm link. While the car moves, the arm looks fine and follows along. But when the car reaches the target and the arm should pick up the object, the arm suddenly “breaks in two”: the base stays on the car, while all upper joints jump back to the world origin and do the pick-and-place there, so it can’t reach the object on the car. I’ve tried many things for weeks and still can’t connect the two devices properly. Could someone please guide me step-by-step as if I’m eight years old and help me fix this?