Drilling And Tapping

Question 1

Is there any specific personal equipment needed when drilling?

Answer 1

Eye protection

Hair net/ tie for long hair

Question 2

What is required nearby when drilling magnesium and titanium alloys?

Answer 2

Fire extinguisher

Question 3

What should be done when setting up the drill to ensure the operation on aircraft is safe?

Answer 3

Remove chuck key and leave it somewhere safe
Warn other on the opposite side of the structure
Ensure the drill motor is suitable for the job

Question 4

What is required from the drill bit when drilling safely?

Answer 4

Use shortest bit possible
Never use a bent bit
Ensure the bit is sharp and at the right point angle
Use a drill guard when using extended bits

Question 5

Why would a drill stop be used on an aircraft?

Answer 5

To protect the skin from any unnecessary damage when drilling

Question 6

What is the max speed for a 3 inch drill bit and what could affect this value?

Answer 6

6000 rpm

Could be affected by material or SRM requirements.

Question 7

What are the two types of pillar drill transmission systems?

Answer 7

Belt and gear

Question 8

How does a belt transmission work for a pillar drill?

Answer 8

Two stacks of V pulleys are used vary the size of the belt as it moves up or down the pulley, depending on how the pulleys are arranged.
As the belt changes size the motor speed ratio changes with it.

Question 9

Can tapered shank drill bits be used on a pillar drill?

Answer 9

Yes, though the chuck may need to be removed to fit larger ones, unless it is designed to hold taper shanks

Question 10

Why would a pillar drill be used over a hand drill?

Answer 10

To achieve precision drilling

Question 11

What other precaution should be done when using a pillar drill?

Answer 11

Clamp the work down

Question 12

What is the pillar drilling sequence?

Answer 12

Select speed and adjust on control panel
Select drill bit and secure into the chuck
Clamp work to the table
Eye protection on
Start the drill motor
Press drill down with feed lever
Swarf forms
Material cut away and hole formed
Turn off drill and remove work

Question 13

What is a threading die?

Answer 13

A circular block with a hole and three or more cutting faces used to cut external threads on to material

Question 14

What is the stock?

Answer 14

The mount for the die, similar to a tapping wrench.

Question 15

What is a tapping wrench?

Answer 15

The mount used to turn the taps

Question 16

What is a tap?

Answer 16

A tool used to cut threads into holes, usually this takes multiple types of taps to build up the cut.

Question 17

What are the channels used for on a tap?

Answer 17

To remove the material that has been cut.

Question 18

What are the 3 types of taps and are all of them required for each threading operation?

Answer 18

Taper tap
Intermediate tap
Bottoming tap
Not always, since some tap kits combine the intermediate and bottoming tap in to one.

Question 19

What could happen if the hole was too small for the tap?

Answer 19

The threads or the tap could break

Question 20

What could happen if the hole being tapped was not fully round?

Answer 20

The tap could break

Question 21

Which diameter of the tap should be the same size as the hole?

Answer 21

Minor diameter

Question 22

Where could you find the tables and recommendations for tap sizes?

Answer 22

Engineering handbooks or manufacturer for tables

Question 23

How many turns should be done to position the tap?

Answer 23

2 turns

Question 24

How many turns should be done before backing off?

Answer 24

Until resistance is felt (usually 2 turns)

Question 25

How should chips be removed from a tap?

Answer 25

With a brush