USING MILLING TECHNIQUES

Question 1

Engineering info on a drawing (5)

Answer 1

• Dimensions
• Scale
• Tolerance
• Material
• Designers name

Question 2

Factors effecting speeds & feeds when milling (4)

Answer 2

• cutting fluid
• material
• Required surface finish
• Machine power

Question 3

Types of work holding equipment (4)

Answer 3

• Vice
• Direct clamp
• Rotary table
• Fixture

Question 4

Requirement for leaving milling machine (3)

Answer 4

• Remove work from holding device
• Remove swarf and clean down machine
• Return surplus material to store

Question 5

DTI plunger type gauge (2)

Answer 5

• Plunger range is 0-12 mm

* 1mm = 1 rev on dial

Question 6

Properties of high speed steel (3)

Answer 6

• Wear resistance
• hardness retention - even at red heat
• Toughness

Question 7

Applications for HSS (2)

Answer 7

• Drills, taps, saw blades

* Wood-turning

Question 8

Procedure for selecting a cutter (2)

Answer 8

• Select tool with correct diameter

* Check teeth are not damaged

Question 9

Checks when assembling a tool for milling a pocket (3)

Answer 9

• Choose a slot drill
• Check cutter and collet is in good condition
• The shank of the cutter and collet match

Question 10

Calculations for cutter RPM (1)

Answer 10

•N = 1000* V/ π*D

• V = surface speed (m/min)
• D = diameter (mm)
• N = speed in rpm

Question 11

Classes of fit (2)

Answer 11

• Clearance fit - the shaft is always smaller than the hole it needs to go into
• interference fit - the shaft is always bigger than the hole it needs to go into

Question 12

Types of milling cutter (2)

Answer 12

• Face mill - for creating a large flat area with a good surface finish
• End mill - for milling the end of a block, outsife profile, or cutting a thin slot or internal pocket

Question 13

Dividing head (1)

Answer 13

•W = R*H/D

• R = ratio
• H = number of holes
• D = number of divisions required
• W = whole number