Thanks for your suggestions. I think Bushi is right with the number of pipes. I will check how it looks with a cylinder on the wrist, like brschmidt sayd. The model will receive also a panel with swith and LED's for Oil, Fuel, Coolingfluid and so on. This would be placed behind the wrist. I think this is the best place for the ergonomy of the left hand/arm. For me the trickyest thing would be the texture, especially at the zone where the normal skin goes over in the more mechanical zone. Thanks again for your help. SHARKEY