To obtain optimum performance of Nook precision ball screws, it is required that the ball screws machined in their case hardened state. When annealing is applied to the end of the ball screw for machining purposes, the lead accuracy is distorted causing the ball nut to lock or jam on the ball screw.
Nook precision ball screw and nut assemblies provide ease of application without the need to machine or anneal the ball screw, as all that is required is installation. Nook precision assemblies offer turnkey solutions that only require a power source (hand operation or motor). All of the elements are available for quick delivery from shelf stock.
When loading an SSN or PRN style ball nuts on an XPR ball screw, depending on the length of the ball screw, the preload condition may vary. The fit between the ball nut and ball screw will range from a slight clearance (~.0005") to no-lash clearance throughout the travel, which may cause a minimal variation in tare drag torque. If a full preload is required select an SGT ground ball screw instead.