The GATE Grind

GATE 2021 ME (ME1) – Question 19

Computer Aided Manufacturing and Automation · NC/CNC machines and CNC programming · 1 mark · Multiple choice

In modern CNC machine tools, the backlash has been eliminated by

  1. Preloaded ballscrews
  2. Rack and pinion
  3. Ratchet and pinion
  4. Slider-crank mechanism

Practise this question in The GATE Grind →

Show answer and explanation

Correct answer: (A) Preloaded ballscrews

Explanation

Preloading the ball nut removes axial clearance between the screw and nut by maintaining contact on opposing load paths. Reversal therefore does not require taking up free play.

The intended mechanism is **preloaded ballscrews (A)**. The other mechanisms alone do not ensure backlash elimination.