Mistake 1: Only verifying the static load rating while neglecting peak impact loads caused by screw inertia and load acceleration/deceleration during operation. Frequent start-stop cycles will result in plastic deformation of the support block.
Mistake 2: Equating the tensile resistance of the support block to the material tensile strength, without considering preload decay of fastening bolts. Frictional slip at connecting interfaces often becomes the weakest link.
Mistake 3: Focusing merely on the basic dynamic axial load of thrust bearings or angular contact bearings. Improper internal bearing layouts will reduce resistance to reverse tension and cause premature fatigue spalling.
Mistake 4: Believing higher rigidity means better tensile performance. Excessive axial rigidity magnifies additional bending moments from misalignment, triggering local yielding on the loaded side.
Mistake 5: Selecting parts directly from empirical tables based on screw diameter and pitch, without checking load transmission paths. Poor structural design causes interrupted force flow and stress concentration.
Mistake 6: Overlooking the difference in linear expansion coefficients between the support block and lead screw under temperature changes. Normal clearance may turn into interference fit and generate extra axial resistance at high temperatures.