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

milling.jpg (4974 bytes)

"Milling Machines"
Milling Machine Maintenance - Lubrication
Milling Home

Proper lubrication of machine tools is the responsibility of the operator. In order to insure that the machine runs properly and maintains its accuracy, regular lubrication is required.

Before operating the milling machine, make sure that all lubricants are at their proper levels. Being that all milling machines are different, it is impossible to cover the lubrication schedule for all of the types of mills found in the machine shop. Use the charts found below as a guide for the proper lubrication points found on most types of mills. Use the chart to find similar lubrication points and the types of lubrication needed for the machines in our shop. If you find that the machine that you are using is drastically different from the machine found in the illustration, ask an instructor for the lubrication schedule for your particular machine.


Figure 1 Horizontal Milling Machine Lubrication


Horizontal Milling Machine

There are individual lubrication systems for the moving parts of the column, the knee and head. Each system is provided with a sight gage to indicate the oil level. Section 1 in Figure 1 shows the left side view of the horizontal milling machine. In this view you will see the oil filter (Figure 2).

 

Rotate the handle of the oil filter twice each day.


Figure 2. Oil Filter.


Spindle Drive Lubrication  Top 

Check the oil level in the spindle reservoir by stopping the machine and checking the level on the oil level gage (Figure 3).


Figure 3. Spindle Drive Oil Level Gauge


Figure 4. Oil Flow Sight Gage.

After checking the reservoir level on the oil level gauge, start the spindle of the machine and check for lubrication flow on the oil flow gauge (Figure 4).
If needed, add oil to the spindle reservoir through the filler cap in the back of the machine (Figure 5). The reservoir holds the oil that lubricates the spindle drive, the spindle drive gearbox and the pulley bracket.


Figure 5. Spindle Reservoir Filler Cap.


Knee Lubrication  Top 

Section 2 in Figure 1 shows the left side view of the horizontal milling machine. In this view you will see the knee lubrication components. The knee lubrication system lubricates the knee drive, feed distribution box, feed and rapid traverse drive brackets, column and knee ways, and the elevating screw. The Filler Cap is located just above the level gauge (Figure 1).


Figure 6. Saddle Lubrication Filler Cap, Pump and Oil Level Gauge.

This filler cap is the cap for the knee reservoir. Check the oil level in the reservoir by stopping the machine and checking the level on the knee oil level gage.

Saddle Lubrication

Section 3 in Figure 1 shows the front view of the horizontal milling machine. In this view you will see the saddle and knee lubrication components. This system lubricates the saddle and table-drive mechanisms, knee and saddle ways and the saddle and table ways. The lubrication system consists of a hand-operated pump (Figure 6). The pump maintains constant pressure to the lubrication system. As the oil in the system gets used, the pump forces more oil to flow. The pump handle should be actuated initially until the handle no longer reaches the bottom of its stroke. As long as the machine is in operation the handle should not be allowed to bottom out. The reservoir can be filled through the filler cap on the saddle.

Arbor Support Lubrication

The arbor support shown as number 4 in Figure 1 needs to have oil visible in the sight glass whenever it is being used.

Miscellaneous Lubrication Points

There are many miscellaneous components on the horizontal milling machine which need to be oiled by hand using filler cups (Figure 7). Filler cups are positioned at numbers 5,6,7,8,9,10 in Figure 1. These filler cups need to be filled every day.


Figure 7. Oil Filler Cups.


Vertical Milling Machine  Top 

There are individual lubrication systems for the moving parts of the column, the knee and head of the vertical milling machine. Each system is provided with a sight gage to indicate the oil level.

Figure 8. Vertical Milling Machine Lubrication

Spindle Drive Lubrication

Section 1 in Figure 8 shows the left side view of the vertical milling machine. In this view you will see the Oil Filter. Rotate the handle of the oil filter twice each day. Check the oil level in the spindle reservoir by stopping the machine and checking the level on the oil level gage. After checking the reservoir level on the oil level gauge, start the spindle of the machine and check for lubrication flow on the oil flow gauge. If needed, add oil to the spindle reservoir through the filler cap in the back of the machine. The reservoir holds the oil that lubricates the spindle drive, the spindle drive gearbox and the pulley bracket.

Spindle Lubrication

Section 2 in Figure 8 shows the spindle head of the vertical milling machine. In this view you will see the spindle lubrication components. The spindle lubrication system lubricates the spindle and the head ways. The flow and level gauge is located on the side of the head (Figure 9). Check to make sure that oil is visible in the gauge.


Figure 9. Spindle Oil flow and Level Gauge.

Knee Lubrication

Section 3 in Figure 8 shows the left side view of the Vertical milling machine. In this view you will see the knee lubrication components. The knee lubrication system lubricates the knee drive, feed distribution box, feed and rapid traverse drive brackets, column and knee ways, and the elevating screw. The Filler Cap for the knee lubrication is located just above the level gauge. Check the oil level in the reservoir by stopping the machine and checking the level on the oil level gage.

Saddle Lubrication

Section 4 in Figure 8 shows the front view of the vertical milling machine. In this view you will see the saddle and knee lubrication components. This system lubricates the saddle and table-drive mechanisms, knee and saddle ways and the saddle and table ways. The lubrication system consists of a hand-operated pump. The pump maintains constant pressure to the lubrication system. As the oil in the system gets used, the pump allows more oil to flow. The pump handle should be actuated initially until the handle no longer reaches the bottom of its stroke. As long as the machine is in operation the handle should not be allowed to bottom out. The reservoir can be filled through the filler cap on the saddle.


Miscellaneous Lubrication Points  Top 

There are many miscellaneous components on the vertical milling machine which need to be oiled by hand using filler cups. Filler cups are positioned at numbers 5, 6, 7, 8, 9, 10, 11, 12, 13 in Figure1. These filler cups need to be filled every day.

Ram Style Vertical Milling Machine

The ram-style vertical milling machine, because of its simplified construction, has only two basic areas in need of lubrication. The head and the way surfaces. The head of the ram style vertical mill has two oil cups (Figure 10) that need to be checked and/or filled before every use.

 


Figure 10. Spindle lubrication for ram-style vertical milling machines. The oil cups feed the spindle bearings lubricant during operation.


Figure 11. Access point for lubrication.

Another point of lubrication is at point A on the left side of the spindle head. There you will find a set-screw (Figure 11).


Figure 12. Lubrication instruction plate.

At six-month intervals you will need to remove the set-screw and grease with lubriplate. On Bridgeport milling machines a lubrication instruction plate is located on the head of the machine (Figure 12).

The plate describes lubrication practices for the Bridgeport milling machine.


Slide Way Lubrication

The way surfaces of the machine are oiled through the lubrication pump located on the knee of the machine (Figure 13).

The pump maintains constant pressure to the lubrication system. As the oil in the system gets used, the pump allows more oil to flow. The pump handle should be actuated initially until the handle no longer reaches the bottom of its stroke. The pump should then be actuated at four hour intervals while the machine is being used. The reservoir can be filled through the filler cap on the top of the reservoir.


Figure 13. Lubrication Reservoir and Pump for the way slides.

Top