A linear motor comprising a DC magnetic field of alternating polarity arranged in a longitudinal axis, a coil assembly located substantially in a plane parallel to and immersed in the alternating magnetic field, said coil assembly containing individual coil loops of essentially rectangular shape and having end turn areas arranged parallel to said longitudinal axis of the magnet field and coil side areas being perpendicular to said longitudinal axis of the magnetic field with each coil side having a coil side width (CSW) and each coil loop having a coil outside width (COW) and coil inside width (CIW) such that COW=CIW+(2.times.CSW) wherein the coils have a coil outside length (COL), forming a coil assembly area (CAA) approximately equal to COW.times.COL and said coil assembly has a coil assembly thickness (CAT) in a direction creating acoil assembly volume (CAV) approximately equal to the coil assembly area (CAA) times the coil assembly thickness (CAT) pursuant to the following equation: CAV.apprxeq.CAT.times.COW.times.COL. wherein said assembly is formed with a plurality of phases each formed in the manner of the first phase, each phase uniformly and sequentially offset from adjacent phases and means for switching current successively between the phases thereby alternating the magnetic fields within the coil assembly sequentially, said plurality of offset phases substantially filling the coil inside width (CIW) of the first phase, such that CIW=CSW.times.(#.phi.-1). The above coil assembly optimally includes a longitudinal opening along the end turn areas within the coil assembly volume allowing non-magnetic metallic members for heat dissipation and structural strength, including a mounting bracket on one end turn area, and a heat sink cap enclosing the opposite end turn area.