key words for lathe bed inspection

Question 1

where to clean out after removing the chuck

Answer 1

draw tube

Question 2

where to place dti

Answer 2

cross slide

Question 3

the layout of gears in headstock

Answer 3

a gear selector is used which is connected to a selector ba, thrust bearing help with load

Question 4

why is the headstock arranged in a geometric progression

Answer 4

this allows for a range of speeds to be selected for the spindle

Question 5

drilling

Answer 5

after using a centre bit a pilot bit must be used to avoid larger drill bits from rubbing against the material.

Question 6

ways of producing a taper

Answer 6

offset tailstock, taper turning attachment, setting over the compound slide

Question 7

how does offsetting the tailstock produce a taper

Answer 7

adjusting the tailstock laterally offsets the tailstock this inclines the axis of the workpiece relative to the cutting tools path
the full length of the bed can be used

only small angles can be cut
damage to the centre holes may occur
only apply to work that can be placed between centres

Question 8

compound slide

Answer 8

setting over the compound slide inclines the tool path relative to the workpiece axis, this is done by using the compound slides protractor base calibrated in degrees
very easy setting over a wide range of angles only short lengths can be cut
and only hand traveresed

Question 9

what is a brazed tip cutting tool

Answer 9

this indexable tip is shaped like a diamond with a hole in the middle to allow it to be screwed in place, made from tungsten carbide and has a 55-degree cutting angle.

Question 10

oblique single point cutting tool name and explain 3

Answer 10

rake angle amount of resistance that is put onto the tool
back rake angle
clearance angle the amount of heat transfer the tool takes

Question 11

state four reasons for chatter marks

Answer 11

1. Spindle speed too high for the material
2. Feed rate too low for the material
3. Work piece isn’t tightened enough in the jaws
4. Too much pressure placed on the tool

Question 12

what will affect the outcome of your turned work

Answer 12

if we didn’t have a fixed steady it would start to flex
deflection
clamping stops
alignment of fixtures

Question 13

• Describe in detail how the lead screw is driven from the headstock spindle.

Answer 13

The lead screw can be connected to the driven gear which revolves at the same speed as the main spindle, so when automatic travel is engaged the lead screw is connected to the driven gear.

Question 14

3. Describe 5 typed of work holding devices used on a centre lathe.

Answer 14

3 jaw chuck
These are self-centring. Used to centre cylindrical or hexagonal shaped pieces

4 jaw chuck
This allows more eccentric shapes to be held but does not self-centre, so you’ll have to do that manually.

Magnetic chuck
Holds the piece without the need for clamping it down

Collet chuck
Allows the user to work on small/long pieces of work

Face plates
Are used to hold heavy and irregular shapes that might not be easy to do held between centres,

Question 15

what are thrust bearings

Answer 15

thrust bearings allows us to put load on it

Question 16

what bearings allow for heavy load

Answer 16

thrust bearing

Question 17

• Describe how to perform safety checks on a lathe

Answer 17

Make sure the machine is equipped with safety guards and emergency stops/brakes and is not showing clear signs of damage.
Operator should use all necessary safety equipment.
Before starting the machine make sure the material is secured and positioned properly. When in operation the machine should be set to the appropriate speed and feed with enough coolant.

Question 18

3. State four reasons for inconsistency of product shape during turning.

Answer 18

Deflection: workpiece could deflect cutting if not rigid enough
Clamping: over tightening of the work holding device will affect the work piece
Stops: stopping travel of the tool bit at a weird angle
Alignment of fixtures: being out of alignment might affect tolerances