Lathe construction features and functions

Lathe Machine consists of

• bed
• headstock
• tailstock
• carriage assembly
• quick change gearbox

Bed made out of gray or ductile cast iron or fabricated from steel by welding. Bed is divided to 2 types, first is the outer way and another one is the inner way.

In the Inner way, headstock and tailstock located in it. By the longitudinal movement for the carriage assembly and towards the centerline of the lather. The bed is needed to clean to avoid damaging to the machine.

Headstock

• mounted on the left side of the lathe machine.

• the function of the headstock is to turn the work piece and where it is suppost to hold the attachments mount.

• the spindle is mounted on the bearings on the headstock and it is hardened and specially ground to fit different type of devices. Spindle speed is controlled by varying the geometry of the drive train

• 3 jaw chucks, collets and centers can be held in the spindle

• To reverse the headstock movement, the lead screw and feed rod will change the direction of the movement of the carriage.

Tailstock

• support the end of the longer work piece
  

• holds cutting tools for internal machining operations

• spindle is graduated to control the depth of the drilling operations.

• fastened into the position by tailstock clamp

• the spindle in the tailstock can be adjusted longfitudinally by rotating hand wheel and locked by tailstock spindle lock

The figure above shows the adjustment for the tailstock and it is made in 2 parts

It allow the top part to move toward or backward from the operator

• For turning tapered parts or aligning the tailstock spindle true with headstock spindle.
• Must be realigned exactly on center when turning a cylindrical part

Carriage Assembly

• move along longitudinally

• H- shaped casting fitted on the outer set of ways

• cross slide mounted on the top of the saddle and moves the cutting tool laterally across the bed by cross feed hand wheel that has a micrometer collar that allows the cutting tools to remove metal.

• Compound Resta mounted on the cross slide and support the tool post and able to swiveled to any angle for taper turning or cross - feed hand wheel.

• Aprona mounted beneath the front of saddle and houses the carriage and cross - slide control mechanisms. The apron hand wheel is used to move the carriage assembly by rack and gears.

Gearbox

• Mounted on the left side of bed and below the headstock

• Houses gears and other mechanisms that transmit various feed rates from the headstock spindle to either of lead screw or feed rod

• Lead screw advances the carriage during threading operations, feed rod moves the carriage during turning, boring and facing operations.