The speed range on the mills or lathes should be set before the machine is turned on.

• A. True
• B. False
• C. Not specified
• D. Depends on operation

Answer: (A)

Setting the spindle speed range before energizing the machine is essential for a safe and successful start. The appropriate speed depends on the tool diameter, material, and the operation you’re performing. If the machine starts at an incorrect speed, the tool can grab the workpiece, chatter, or break, risking injury and damaging the part or tool. By selecting the correct belt/gears (or CNC speed) while the machine is off, you ensure a controlled ramp to the intended speed and a safer, smoother kickoff. Once the setting is verified, power up and begin the cut at that speed.