1. Apparatus wherein a tool is moved through a three-dimensional space and along a predetermined path in response to signals and in which the tool is also movable to an extended position so that the tool can perform work on an object comprising: (a) a fixed base; (b) a plurality of interconnected elements having one end connected to said base and terminating at another end; (c) means responsive to said signals to move said interconnected elements and to move said another end through three dimensions to a desired location; (d) a tool assembly attached to said another end; (e) a tool holder attached to said tool assembly; (f) a tool mounted in said tool holder; (g) means responsive to said signals to move said tool assembly to adjust a first angular relationship between said tool and said object; (h) means responsive to said signals to move said tool holder to adjust a second angular relationship between said tool and said object; (i) extending means connected to said tool assembly for permitting extended movement of said tool wherein said extending means includes a first position in which said first and second angular relationships are adjusted and a second position in which said tool is moved to an extended position in order to access a relatively more remote work area; (j) arm means operably connected to said extending means; and (k) shaft means connected to said arm means, said shaft means being at a fixed, predetermined angle relative to said arm means, said angle being selected to optimize the extension of said tool when said extending means is in said second position.