Here is the basic process I used to create my digger.
I began by setting up image planes of the front, back and side views.
I then made a simple block out of the larger components of my digger.
The first section I added detail to was the cab and the rear section.
I then added detail to the arm sections, the joint and the base. The final bit i made was the undercarriage.
Here is my almost finished model.
