Excvavator as used in my Inverse Kinematics program available on Udemy. Are you struggling with IK and need assistance in figuring out how it works? I have a course available here! (Use coupon code: 896402CEBED802BB3AC5 if sale on Udemy is not on. Valid until 25 June)
The excavator is designed to be easily controlled using one bone. Use the bone 'CO: Bucket' to adjust the arm and bucket itself. The excavator cabin/vehicle itself will always track to this bone correctly. If you need to rotate the bucket, you simply rotate it on X axis.