The Bridgeport manual milling machine is one of the most common machines seen in machine shops in the modern era. They are capable of many different types of operations including drilling, machining and boring. In order to keep them running for many years, it is imperative to lubricate their internal parts at particular intervals by adding lubricant to strategically placed reservoirs on a weekly or even daily basis in some cases. A properly lubricated Bridgeport milling machine can last decades and pay for itself many times over the long run.
Press the centralized lubrication plunger located on the left side of the machine. This sends oil through small tubes to lubricate the ways for the table as well as for any movement in the area of the table. If the oil supply is low, fill the reservoir with Vectra No. 2 oil, which is available at machine shop supply stores as well as online.
Pour a few drops into the small openings near the quill feed and quill bearings twice a day. This will keep the up and down motion of the quill lubricated as it is often used heavily during production. Keep the oil topped up to ensure fluid motion of the quill. Lift the small hinged top to access the tube that allows the oil to flow to the moving parts.
Lubricate the spindle down feed bearings when using this feature on a Bridgeport milling machine. These mills have automatic down feeds available and the contact surfaces must be lubricated for smooth downward action when machining. Failure to lubricate the spindle down feed may result in choppy downward movement.
Lubricate the drive bevel gears located at the top of the mechanical feed box on a daily basis by adding two drops of Vectra oil. This action will keep the automatic feed for the X axis running smoothly. Also, add oil to the change gears reservoir. This does not need daily attention as you only would change gears for the automatic feed on occasion.
Lubricate the draw bar once a week by adding five drops at the draw bar nut. The draw bar holds the tool in place with a threaded rod that spins, so lubrication in this area is necessary to keep the spindle running smoothly. A belt turns the spindle and draw bar at the necessary speed depending on the gear you have chosen.