Scanning for Ideas: Compact stepper-motor actuator fills the bill
The Digit, a stepper-motor actuator from Ultra Motion, Cutchogue, N.Y., is based on an in-line design that couples the motor directly to the leadscrew. This makes for a compact package, one that measures 5.4-in. long when equipped with a NEMA-176 motor and about 6.6-in. long when a NEMA-23 stepper motor is used. Coupling the motor to the leadscrew with an Acme or ball nut gives the actuator more accuracy and a longer life.
Repeatability of the Digit is ±0.00004 in., and resolution is 0.00004 in./step. The device can exert up to 400 lb of force and move at up to 15 ips.