Table Type Horizontal Boring Mills

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Horizontal boring mills are machine tools that are used for milling surfaces and drilling and boring holes in a work piece. The spindle is oriented in the horizontal position. Of the three types -- planer, floor and table -- the table type is the most common. Its so common and versatile, in fact, that its also known as the universal type. Table type boring machines can accomplish a number of machining operations, including reaming, tapping, threading, drilling, milling, and boring.

The horizontal boring mill has a spindle and headstock that is situated parallel to the floor, and a worktable supported by ways underneath it. The worktable is movable in the table type machine and can be brought into and away from the spindle for drilling and boring. Typically, horizontal boring machines are large, heavy-duty industrial machines used to machine large components such as big pump housings, valves or machine frames or other large parts. Horizontal boring machines can come with CNC controls for higher productivity and accuracy.

A table type horizontal boring mill usually has the following parts:

* ...
... Headstock, which supports the spindle and spindle drive motor and gearing.

* Column base, which supports the column and contains the feed drive mechanisms and gears.

* Column, which supports the headstock on precision ways that accurately guide the headstocks vertical motion. The column also houses counterweights to balance the weight of the headstock.

* End support column (often), which supports the end of a boring bar. The end supports bearing block travels in tandem with the headstock. This is used for line boring holes through large castings or fabrications for precision aligning of shafts.

* Bed and bed ways, used to hold the table support system (saddle) and main column and end support column.

* Table, which holds the work and secures it. It travels at a right angle to the spindle (the X axis) and generally also travels towards and away from the spindle (W axis).

* Saddle, which supports the table and contains the mechanisms that let the table move in different directions.

Table type boring mills typically have two types of boring bars; stub bars and line bars. A stub bar is supported at the spindle end and is used to bore a hole relatively close to the headstock. The tool itself usually has one cutting edge, or two, with one on each side of the boring bar.

The two most important things to look for structurally in a horizontal boring mill are rigidity and robust construction and working parts. Since these machines often work around the clock, maintenance and durability are essential. Computer control has helped accuracy immensely, but wear or poor maintenance can affect that machines inherent accuracy. When purchasing a table-type horizontal boring mill, these are some things to look for:

* Make sure the machine bed is level vertically and horizontally.

* Examine all the guideways for wear or scoring.

* Make sure the table top is parallel to the guideways for the bed.

* Inspect all cables, hoses and plugs.

* Make sure the edge of the table is parallel to the saddle guideways.

* Make sure that the edge of the table sits square with the spindle.

* Ensure that the spindle and table top are parallel with each other.

When the machine is running, check the spindle for concentricity and run-out using a dial indicator, and run the machine through a complete cycle to verify all systems. Make sure that the emergency stop buttons and other safety features are all in good working order.