Welcome to: Engine Lathe - Basic Components and Operation.
In this learning activity, you'll explore the engine lathe,
its basic components, and you'll learn to
operate its machine controls.
Let's begin with the main components of the engine lathe.
The five main parts are the bed,
the headstock, the carriage, the tail stock, and the gearbox.
The bed is the large casting that
supports and aligns the components.
It's the backbone of the lathe.
The bed ways, or ways, are the precision machined surfaces
that sit on top of the bed.
These align all of the components.
It's critical to maintain the condition and accuracy of the bed ways.
The rack, or gear rack as it's sometimes referred to, attaches to the bed.
The rack links the pinion gear that's attached to the carriage hand wheel.
This makes the longitudinal movements of the carriage possible.
The headstock houses the spindle and the components that drive
the spindle and the feed gears.
The spindle holds and drives the workpiece.
The headstock also houses the change or end gears.
Power from the headstock to the
gearbox transmits through the end gear
train to the feed rod and the lead screw.
The size and positioning of the end gears
creates a ratio that controls the feed rate.
The feed rod transmits power from the headstock to the carriage for feeding operations.
The lead screw transmits power from the headstock to
the carriage for screw thread cutting operations.
On some lesser types of lathes,
the feed rod and the lead screw are used
for both the feed and the thread cutting
power transmission.
The carriage houses the saddle, the cross slide, and the apron.
The main function of the carriage is to position the tool along the lathe bed.
The saddle sits on top of the apron. It rides along the bed ways
and guides the apron and cross slide.
The apron houses the components to
control and drive the cross slide and the saddle.
The apron rides along the bed ways.
The cross slide controls the axis
direction opposite of the bed ways.
This axis is the x-axis.
It controls the diameter of your work.
The compound rest sits on top of the cross slide.
The tool is mounted in the compound rest.
It can be swiveled to any angle and it
typically cuts chamfers or tapers.
However, it must be used when cutting threads.
You can only feed the compound rest
by hand, because there is no power to it.
The cross slide hand wheel allows you to
manually position and/or hand feed the
compound rest in the x-axis.
The carriage hand wheel allows you to
manually position and/or hand feed the
carriage in the longitudinal or z-axis.
The tailstock supports the right end of the work.
The tailstock also holds tools
for machining operations such as
drilling, reaming, and tamping.
The tail stock is made up of a two-piece casting.
The lower part, the base, clamps to the ways.
You can adjust the upper part using the set screw.
Adjustments can be made to
turn slight tapers or for on-lining the
tail stock to the headstock.
The main power switch supplies
power to the machine.
The emergency stop button turns off the
power to the machine motor.
The motor start button starts the
electric drive motor for the machine.
While it doesn't control the spindle, it
does supply the power.
The spindle speed selector allows the
operator to adjust the machine's spindle speed.
The quick change gearbox provides
all of the thread and feed settings through a series of gears.
You can see the gear settings on the data plates.
These provide the lever settings and the
end gear combinations.
The spindle clutch and brake lever
controls the spindle rotation.
You can use this lever to control the spindle direction,
spindle on, and spindle off.
On some machines, a magnetic brake turns off the spindle.
To turn the spindle in the forward direction, push down on the spindle clutch.
To turn the spindle in the reverse direction, pull up on the spindle clutch.
Placing a spindle clutch in the middle position applies the brake.
Some lathe styles have a foot-operated brake.
The power feed lever controls the
automatic movement of the axes.
The two axes of movement associated with the
lathes are the z- and the x-axis.
The z-axis is the longitudinal axis while the
x-axis is the cross slide axis.
Feed access selector allows you to select the
axis to send the power to.
If you want to feed along the z-axis, push the selector all the way in.
If you wanted to power feed the cross slide, pull the selector all the way out.
Use the neutral, or middle, position for threading.
The feed direction lever, or feed reverse
lever, controls the direction of lead and feed screws.
To change the direction of the automatic
feed on the lathe, change the position of
the feed direction lever.
Pulling the saddle lubrication handle pressurizes
the lubrication system and pumps oil to
the longitudinal and cross slides.
The halfnut lever engages the carriage
directly to the lead screw.
It's only used for threading.
Also, the halfnut lever only engages when the feed is set
in the neutral position.
The thread chasing dial is used for threading.
It works off the lead screw and is used as
a tracking device.
The dial tells you when to engage the halfnut lever, so the
tool follows the same thread groove every time.
The carriage lock bolt tightens the carriage to
the bed of the machine.
It's typically used during facing, grooving, or parting operations.
The gib screw takes up clearance between
the gib and the dovetail.
This clearance occurs normally due to where most lathes
have similar control mechanisms and
operating handles; however, some machines
have entirely different driving mechanisms.
Before using any lathes, make sure you can correctly identify all of
the controls and understand how they work.
You've completed: Engine Lathe: Basic Components and Operation.