[Rimrock]

Hi, welcome. It's not a secret that scratch building functional RC models of metal in many cases demands quite some specialised tools, as lathe, mill, and specialized skills. Some whoever just use basic tools, on the 'angle grinder level', and are able to create working models. Many people who scratch build stuff, first of all have a great interest in metal crafts and mechanics in general, and love the planning and building process. Then you got the majority within the hobby who first of all wants to operate the equipment, and spend as little time as possible building stuff. There are several suppliers of excavators these days, most are pre assembled, but some are partly assembled and un-painted.