Lead Screw Thread Inspection

Customer Need

A medical device company was experiencing a high failure rate on a component of their handheld electronic devices. The reason for the failure was due to damage on the tread of the lead screw. Prior to assembling the product they wanted an application that would allow them to perform a test on it to determine if the part was damaged.


CSC designed and fabricated a benchtop system that used a combination linear/rotary voice coil actuator to thread the male screw into a female threaded fixture while detecting small differences in rotary motion that indicate damaged threads. A torque sensor is also incorporated to independently measure the torque during threading.

Using a force feedback linear actuator, a custom application brings a threaded rod down to contact the nut under test. The actuator then matches the thread start up, and then spins through the test part. The reactive force is recorded and analyzed to determine if and where the test torque exceeds specification.

System Components

  • Intel Atom PC
  • SMAC Linear & Rotary Actuator
  • SMAC Dual Axis Controller
  • Keyence Power Supply


The system was successfully delivered to the customer on time and on budget. The implementation resulted in them being able to prevent damaged parts to be used in the assembly process which led to fewer repairs and an increase in profit.