The HV and LV 34 frame stepper motors come standard with a double flat output shaft. The double flat output shaft has two flats machined 90 degrees apart on the end of the output shaft. This type of shaft is NOT recommended for use with a standard Parker Bayside gearheads which use a collar clamp to clamp the motor shaft to the input of the gearhead. The collar clamp input is designed for a smooth round shaft, which maximizes the surface area of the motor shaft to be clamped. The double flat reduces this surface area almost half, and furthermore, full clamping force cannot be attained because the shaft diameter is effectively reduced by the double flat.
More info on shaft features and Parker Gearheads can be found here: Motor Shaft Features and Parker Gearhead Mounting
To address this problem, Parker has added new standard part numbers which allow a round shaft output on the HV and LV 34 stepper motors. Below are the part numbers which should be ordered when using these motors with a Parker gearhead:
LV34x-03-yy (single shaft, round option)
HV34x-03-yy (single shaft, round option)
LV34x-04-yy (double shaft, round option)
HV34x-04-yy (double shaft, round option)