solved problems on drilling machine calculations

SOLVED PROBLEMS ON DRILLING MACHINE CALCULATIONS

Problem 3.6

Calculate the spindle speed to drill a hole of 50 mm using the cutting speed as 25m/min.

Given data:

Diameter of hole, D = 50 mm

Cutting speed, V = 25 m/min

Solution:

Problem 3.7

Calculate the feed in mm/rev to drill a hole of 30 mm in one minute to a plate thickness of 40 mm and using a spindle speed of 500 rpm.

Given data:

Diameter of hole, D = 30 mm 

Machining time, t = 1 minute

Thickness of plate, tp = 40 mm

Spindle speed, N = 500 rpm

Solution:

Problem 3.8

Calculate the machining time required for making 15 holes on a MS plate of 30 mm thickness with the following data:

Drill diameter = 25 mm

Cutting speed = 20 m/min and

Feed = 0.13 mm/rev

Given data:

Number of holes to be drilled = 15 

Thickness of the plate, tp = 30 mm

Drill diameter, D =25 mm 

Cutting speed, N = 20 m/min 

Feed, f = 0.13 mm/rev

Solution:

Problem 3.9

A 40 mm HSS drill is used to drill a hole in a cast iron block of 80 mm thick. Determine the time required to drill the hole if the feed is 0.2 mm/rev. Assume an over travel of drill as 5 mm. The cutting speed is 22 m/min.

Given data:

Drill diameter, D = 40 mm

Thickness of CI block = 80 mm

Feed, f = 0.2 mm/rev

Over travel, S = 5mm

Cutting speed, V = 22 m/min

Solution:

Problem 3.10

Calculate the power required to drill 25 mm diameter hole in aluminium plate at a feed of 0.2 mm/rev and at a drill speed 400 rpm. Also determine the volume of metal removed per unit minute.

Given data:

Diameter of drill, D = 25 mm

Material: Aluminium

Feed, f = 0.2 mm/rev

Drill speed, N = 400 rpm

Solution: