What Are The Main Parts Of A Bridgeport Mill?
The knee is a heavy-duty casting that supports the worktable, moving vertically on a dovetail on the machine’s column. This enables operators to adjust the table’s height manually using the vertical feed crank, allowing knee travel along the Z-axis. Once the knee is in the correct position, the operator can lock it.
The turret sits on top of the column and connects it with the ram, rotating as needed by loosening up a series of nuts. This enables the cutting head to access otherwise hard-to-reach areas on the worktable. Some mills come with a protractor marking on the turret, allowing precise positioning along the worktable.
The ram is locked into the dovetail assembly on top of the turret, enabling it to move in and out using a rack and pinion mechanism and a crank. A large hole on the back of the ram allows for mounting attachments. And because the ram is on a turret, the operator can swing the attachment 180 degrees and use it above the worktable.
The saddle is responsible for supporting the worktable and is driven by a screw, moving in and out along the Y-axis on a dovetail alignment. Operators can move it manually using the cross-feed crank or with a power feed. Once the desired position is achieved, the saddle can be locked in place.
The table sits on top of the saddle and moves horizontally along the X-axis, allowing for machining of workpieces. Operators can move the table manually using handwheels or engage the power feed if the machine has one. Locking levers minimize vibrations, and T-slots machined into the table’s surface aid in clamping workpieces or vises for machining.
The head houses the spindle and the quill. The original Bridgeport mill has a C Head, but most come with a J Head. The spindle speed range varies depending on the head and motor attached to the machine. Operators can swivel the head 90 degrees left or right and 45 degrees up or down, with protractors on the tilt joints for precision.
The quill is a unique feature of the Bridgeport mill, allowing it to function as a drill press by moving the spindle up and down using the quill feed handle. Operators can move it manually or with an optional power quill feed. The quill travel is 5″, and the diameter is 3.375″. For boring operations, operators can raise and lower the quill slowly.