Customised stepper motors with a sealed front shaft are available from Astrosyn International Technology. Originally intended for the telecoms market for external use in mobile phone masts, the motors were designed to be weather resistant and to operate at low temperatures. These high torque models draw a low current and have special bearings to enable operation over a wide range of temperatures from +70 to -40 deg C.
An unusual feature of the motors is that the front face where the shaft enters the unit is sealed against moisture, unlike most other motors where it is more usual for the rear end to be sealed.
Available in NEMA frame sizes 17, 23 and 34, and with all standard electrical and performance specifications, the motors are ideal for applications in demanding environments where water, oil or dust is likely to be present.