TPC 327

Question 1

You will probably use the dividing head most often to machine?

Answer 1

Shapes, like gear teeth

Question 2

What machining method relies on the index holes around the spindle?

Answer 2

Direct indexing

Question 3

With a gear ratio of 40:1 how many times must you turn the worm gear and spindle to complete one 360 degree rotation?

Answer 3

40 turns

Question 4

Indexing fractions of a turn formula

Answer 4

T= 40/N

Question 5

In simple angular indexing one crank turn produces?

Answer 5

360/40 or 9 degrees

Question 6

For simple angular indexing use any circle in the index plate with a total number of holes that can be divided by?

Answer 6

Nine, for example 27,36,45, or 54

Question 7

one turn of the crank moves the spindle how many degrees?

Answer 7

9 degrees

Question 8

In compound indexing, you first turn the crank, as in simple indexing. Next….

Answer 8

You turn the index plate itself to provide the final index

Question 9

Differential indexing is similar to, but more accurate than?

Answer 9

Compound indexing

Question 10

How does a universal dividing head differ from a plain dividing head?

Answer 10

The spindle nose can be rotated 90 degrees from parallel with the tabletop to a perpendicular position

Question 11

Workpieces can be held between the center in the spindle nose and the center in the?

Answer 11

Foot stock

Question 12

The power flow moves from the dividing head spindle to the driver, from the driver to the dog, and then from the dog to the…?

Answer 12

Workpiece

Question 13

How do you support a workpiece in a dividing head chuck?

Answer 13

With the footstock center or a steady rest

Question 14

If you straddle mill a hexagonal bolt head how many cuts are needed?

Answer 14

Only three

Question 15

How to prevent chips from falling into the spindle while the nose is pointing upward?

Answer 15

By inserting a specifically made cap over the spindle opening

Question 16

What indexing method does not count for the hole it was in ( the zero hole )

Answer 16

Direct indexing method

Question 17

How do you use the plain indexing method?

Answer 17

By leaving the worm and worm gear in the engaged position

Question 18

Make your rough and finish cuts to mill the first side of the hexagon. Retract the pin and turn the crank clockwise six full revolutions and then continue until the pin reaches?

Answer 18

The hole indicated by the second sector arm. This is for plain indexing

Question 19

Straddle milling a hexagon

Answer 19

You will mill two sides at a time and need only position the workpiece 3 times

Question 20

When will you find the dividing head useful?

Answer 20

Whenever you must drill or bore a series of holes in a circle

Question 21

Cutting the teeth in spur gears is a type of form milling. That is the work is done with?

Answer 21

Special profile cutters which form the sides of the teeth in a gear blank

Question 22

Spur gear OD formula

Answer 22

OD = number of teeth + 2
————————-
Diametral pitch

Question 23

Several things affect cutter selection when you mill gear teeth, they are?

Answer 23

Diametral pitch of the gear
Number of teeth
Material of the gear blank

Question 24

The tooth spaces in a small gear have a different size and shape than those in a larger gear with the same?

Answer 24

Diametral pitch

Question 25

A series of how many cutters has been developed to suit the different number of gear teeth?

Answer 25

Eight cutters

Question 26

Many gear blanks are too large to be mounted on a dividing head. In such cases they are mounted on a?

Answer 26

Rotary table

Question 27

Use a micrometer to check?

Answer 27

The dimension over pins

Question 28

Gear tooth vernier calipers are used to check?

Answer 28

Tooth thickness at the gears pitch circle

Question 29

The AB line is called?

Answer 29

The lead of the helix

Question 30

What is pitch?

Answer 30

Pitch is another term used in describing a helix. Pitch is the distance between adjacent helices that are wound on a common cylinder

Question 31

The milling machine lead determines?

Answer 31

The lead of the helix it will produce

Question 32

You use a system of gearing called _____ between the lead screw of the milling machine and the worm shaft of the dividing head.

Answer 32

Change gears

Question 33

Lm = milling machine lead Lh = lead of the helix to be cut Tg = number of teeth in the dividing head Tn = number of teeth in the driven gears

Answer 33

Lm = Tg — — Lh Tn

Question 34

The worm shaft of the dividing head is meant to utilize how many gears?

Answer 34

Four gears

Question 35

To expand fractions what do you do?

Answer 35

Multiply the numerators and denominators of both fractions by a number which produces figures to match the numbers of teeth on the change gears

Question 36

Drive systems with three gears can be used to cut both right hand or a left hand helix by reversing the direction of gear rotation of the?

Answer 36

Dividing head spindle

Question 37

To determine how far apart the 15 teeth are on the circumference of the work piece what do you do?

Answer 37

Divide 360 by 15

Question 38

You must swivel the table 12 degrees in order to?

Answer 38

Cut the 12 degree helix angle

Question 39

If you draw the cutter back through the work what could happen?

Answer 39

You could damage the critical features of the tooth surfaces

Question 40

Normal diametral pitch is a measurement you will use when describing?

Answer 40

The proportions of helical gear teeth. This differs from the circular pitch used to describe tooth dimensions in spur gears

Question 41

After you mill each tooth why should you lower the table?

Answer 41

So you do not drag the cutter back through the newly cut tooth space

Question 42

What do cams do?

Answer 42

They change the direction of motion of machine parts

Question 43

Although the cam forces the follower upward, the system depends on what to bring the follower back down to its starting position.

Answer 43

It depends on gravity, a spring, or some other force

Question 44

What is cam rise?

Answer 44

Rise is the distance that one lobe moves the follower from its starting point

Question 45

What is cam lead?

Answer 45

Lead of the cam is the total distance that a lobe on a uniform-rise cam would move the follower if the lobe extended a full 360

Question 46

How do you mill a uniform rise cam

Answer 46

You do this by holding the workpiece in a dividing head whose spindle is geared to the milling machine lead screw. You must use a vertical milling attachment for this setup

Question 47

The axis of the dividing head spindle and the axis of the cutter must always be?

Answer 47

Parallel, they must also be at some angle other than horizontal when milling plate cams

Question 48

Assume the rise of each lobe in the cam is?

Answer 48

.160 in.

Question 49

L = R x 36 —— C

Answer 49

R = lobe rise C = degrees of circumference that the lobe occupies

Question 50

The incremental cut method is most often used to mill cams having?

Answer 50

A non uniform rise