A method of constructing an electric linear displacement motor (20) for use in a testing device (12) includes providing a stator (22) having as stator housing (28) with internal coils (23) and a through bore extending from a first end (34) of the stator housing (28) to the second end (36) of the housing (28). First and second end supports (54 and 56) are connected to the first and second ends (34 and 36) of the stator housing (28). An armature (24) having magnets retained therein is inserted into the stator housing (28) such of the armature (24) is supported by the first end support (54) and the second end support (56). A plurality of set screws (60) are inserted into threaded openings (32) proximate both the first end and the second end (34 and 36) of the housing(28). The set screws (60) then support and retain the armature (24) such that there is an annular gap between the armature (24) and the coils (23).