Machine Shop Home  
  Introduction  |  Safety  |   Milling Machines  |  Speeds/Feeds  |  Cutting Tools  |  Broaching |  Projects  |  Tests

milling.jpg (4974 bytes)

"Horizontal Milling Machine"
Machine Construction

Mill Home
The main parts of the horizontal mill are the; base, column, knee, saddle, table, spindle, overarm and arbor supports. Below you will find illustrations of a horizontal milling machines and it’s parts. Study these parts and be ready to answer questions concerning their names locations and uses.
Figure 1 Horizontal Milling Machine

Column-The column of the milling machine, along with the base, are the major structural components. They hold, align, and support the rest of the machine.

Table-Holds and secures the workpiece for machining.

Saddle-The saddle is attached to the knee. The saddle provides the in and out, or Y axis table travel.

Knee-The knee supports the saddle and the table. The knee can be moved up and down for workpiece positioning.

Base- The base of the milling machine, along with the column, are the major structural components. They hold, align, and support the rest of the machine.

Spindle-The spindle holds the tool and provides the actual tool rotation.

Spindle Reverse Lever-The position of this lever determines the spindle direction. The three positions of the handle are; In, Middle, and Out. The middle position is the neutral position. Never move the spindle reverse lever when the spindle is turning.

Spindle Speed Selection Lever-The spindle speed selection lever is used to change the spindle R.P.M. setting. This type of machine has a geared head so the spindle speed can only be changed when the spindle is stopped.

Spindle Clutch Lever-The spindle clutch lever engages the spindle clutch to the motor. By manipulating the spindle clutch lever the operator can start and stop the spindle.

Feed Rate Selection Lever-The feed rate selection lever is used to change the feed rate setting. The feed rate settings are expressed in inches per minute.

Motor Start and Stop Buttons- The motor start and stop buttons control the power to the main motor for the machine.


Figure 2 Horizontal Milling Machine Components

Clamps- The knee, table and saddle all come equipped with clamps. The clamps are used to maintain the position of their respective components. All of the clamps should be locked when machining, except the clamp for the axis that is moving.

Handles-The table and saddle handles are used to manually position the part with respect to the tool.

Knee Crank-The knee crank is used to raise and lower the knee.

Table Feed Directional Lever- The table feed directional lever establishes the direction of table feed. When the table feed directional lever is positioned to the left or right, the table will feed in that direction at the selected feed rate or at a rapid traverse rate when using the rapid traverse lever.

Saddle Feed Directional Lever- The saddle feed directional lever establishes the direction of in and out feed. When the saddle feed directional lever is positioned to the left or right, the table will feed in or out at the selected feed rate or at a rapid traverse rate when using the rapid traverse lever.


Figure 3 Horizontal Milling Machine Components

       Fast/Slow Speed Range

Lever- This lever is used to put the spindle in the Fast/Slow gear range. The Fast/Slow gear range lever allows the operator to select the speed range from which to set the R.P.M. setting from. Turn the spindle by hand while engaging this lever. This will help mesh the gears.

Draw In Bolt-The arbor draw in bolt draws the tool holder into the spindle. The arbor draw bolt is equipped with a jam nut to keep the draw in bolt from loosening up during operation.

Rapid Traverse Lever- The rapid traverse lever engages the rapid traverse gear on the feed motor. The rapid traverse is used for rapid table positioning. The appropriate feed direction lever must be engaged in order for the rapid traverse lever to be used.

Oil Flow Sight Gage-The oil flow sight gage assures to the operator that while the spindle is turning it is being properly lubricated. When the spindle clutch is engaged a steady flow of oil should be visible in this sight gage.

Oil Level Sight Gage-The oil level sight gage indicates the oil reservoir level. The oil level in this sight gage should be visible at all times.


Figure 4 Arbor Support Components

Arbor Support-The arbor support supports the end of the arbor that is opposite the spindle. The arbor support is attached to the overarms bars.

Arbor Support Lock Nut-The arbor support lock nut fastens the arbor support to the overarm bars.

Overarm Bars-The Overarm bars align and support the arbor support.

Oil Reservoir-The oil reservoir holds and distributes oil to the overarm support bushing and arbor bearing collar. Proper lubrication and fit between the arbor bearing collar and the arbor support bushing are crucial.

Arbor Support Bushing Adaptor-The bushing adaptor comes in various sizes. The bushing adaptor allows the operator to use different size arbor support bushings in the same arbor support and also allows for slight adjustments for fit between the bushing and the collar.

Top  |  Next