• Single, fractional, or multi-revolution indexing
  • Torque capacity up to 20 lb·in
  • Indexing accuracy ±5º
  • Non-cumulative indexing error
  • Available for CW or CCW operation
  • Voltage: 24 VDC standard, 12 VDC optional
  • Optional 2-pin male connector
  • Low drag idling
  • Input load carried by input module ball bearing
  • Optional clamp for infinite phasing of output
  • Output anti-overrun option
  • Copying machines
  • Document handlers
  • Medical/diagnostic equipment
Unit of Measure


A – Diameter + .002 in/+ .050 mm

N/A .2500 in

Additional Information

Input module
Input modules are available for driving the clutch input, Gearbelt pulleys (1/5" pitch) for the 3/8" belt width are standard. Other pulley styles and/ or sizes, gears, or sprockets are also available as specials. An important feature of the input modules is that they are supported by an integral ball bearing which will efficiently sustain high bearing loads caused by belt tension, thus protecting the clutch.


The SP-1611 is an electromagnetically actuated, unidirectional, spring wrapped clutch. It is designed for use in cyclic or random stepping applications. One, two, or four steps/revolution are standard. The basic clutch consists of an input drum, output drum, clutch spring, control collar and an electromagnetic actuator. In operation, the clutch input is continuously rotating, and the output is stationary whenever the solenoid is deenergized.

However, when an short electrical pulse is impressed on the coil, the clapper is pulled away from the control collar. The release of the control collar frees the spring to wind down on the input drum and to accelerate the stationary output to the speed of the input. The duration of the pulse is shorter than the time interval required for the indexing step. As the pulse voltage goes to zero, the actuator clapper returns under the influence of two return springs, to stop the control collar decouple the clutch spring from the input, and to bring the output to rest.


1. Engage the fixed anti-rotation pin with the clutch's anti-rotation slot.
2. Line up the input pulley and belt with the drive pulley and lock it in place.
3. Couple the input module pulley to the clutch's input by engaging the module's three drive pins.
4. Install phasing clamp engaging the slot on the clutch output. Phase the output shaft and lock it in place.
5. Install the shaft output retainers.