The CRK series from Oriental Motor USA Corp (Torrance, CA) combines a five-phase stepping motor with a compact, low-vibration microstepping driver. In microstep operating mode, the driver provides 25 preset angle selections up to a capability of 250 microsteps per full step. The basic angle can be adjusted to match a two-phase stepping motor's step angle. The series is available in four frame sizes: 20 mm, 28 mm, 42 mm, and 60 mm. Motors are available with step motor holding torques ranging from 3.2 oz-in to 230 oz-in.
The standard tapered hob TH gear type has gear ratios from 3.6:1 to 30:1, with a maximum backlash of 60 arc-minutes. The planetary PN gear type possesses gear ratios from 5:1 to 50:1, with a maximum backlash of 3 arc-minutes. The harmonic HG gear type provides gear ratios of 50:1 and 100:1 with no backlash.