CNC Milling 19 May Mock Test

The factor that will affect the selection of spindle speed on a milling operation is

• size of workpiece

• diameter of cutter

• shape of workpiece

• type of machine used

A diameter 20 mm slot drill is used to mill a slot with a cutting speed of 70 m/min. Determine the spindle speed of the CNC machining centre.

• 1014 rpm

• 1114 rpm

• 1214 rpm

• 1314 rpm

Determine the spindle speed to cut a mild steel work piece using diameter 20 mm end mill. Cutting speed for mild steel is 33 m/min.

• 205 rpm

• 525 rpm

• 605 rpm

• 1000 rpm

Determine the actual feedrate of the machine when Rapid Override is set at 60% on the machine controller if the machine maximum feedrate is 20 m/min.

• 11 m/min

• 12 m/min

• 13 m/min

• 14 m/min

If the feedrate is 0.15 mm/rev of the cutter and the spindle speed is 1500 rpm, calculate the feed in mm/min.

• 200 mm/min

• 225 mm/min

• 250 mm/min

• 275 mm/min

A diameter 65 mm shell end mill carbide tool is used to face a mild steel work piece using a cutting speed of 56 m/min. Determine the spindle speed of the CNC machining centre.

• 220 rpm

• 274 rpm

• 320 rpm

• 354 rpm

The formula to determine table feedrate for CNC milling machine is F = S × Sz × N. Identify N.

• Number of cutter

• Number of rotations

• Number of machines

• Number of cutter's teeth

Identify a factor which does not affect the CNC machine table feed rate.

• Coolant

• Brand new cutter

• Material to be cut

• Depth and width of cut

A diameter 50 mm carbide face mill is used to mill a mild steel workpiece at a cutting speed of 30 m/min. Calculate the spindle speed in rpm. Π = 3.142.

• 76 rpm

• 190 rpm

• 530 rpm

• 600 rpm

The spindle speed used for countersink operation should be at

• any spindle speed

• spindle speed with lower range

• spindle speed with higher range

• spindle speed with extremely high range