1.0 Technical Information
The Symmetrical Mill is specifically designed for machining two opposite faces parallel to each other. Typical applications for this machine are Mill Stands in Steel and Alumina Rolling Mills, which periodically require the Wear Plate Surfaces to be dressed. All mill stand sizes can be accommodated but can involve special preparation.

The Symmetrical Mill consists of two vertical mill beds designed as columns such that they need only be supported at each end. The support is achieved by jacking against top and bottom frames, which in turn are supported by the top and bottom window areas on both Drive and Operator sides. These Vertical mill beds are positioned such that a linear rail on each bed is on the approximate centreline of the mill stand (equal distant from the entry and exit wear plate surfaces). A cross bed runs between the two mill beds and is designed such that the milling cutter can machine a wear plate surface. With one side complete, the cross bed is swung 180 degrees so that the cutter can now machine the opposite wear plate surface.

The cross bed is counter balanced hydraulically and this system also enables a work platform to follow the cross bed up and down the Mill Stand Windows which is capable of carrying two men.

Two Symmetrical Mills can be installed on common top and bottom frames. This assembly is carried out on the operator floor and the twin machine assembly then slid into the mill stand on a track from the Operator Side. This allows one Symmetrical Mill to be placed in the Drive Side Window and the second to be placed in the Operator Side window.

The Symmetrical Mills are adjusted to be parallel to the centreline of the mill stand using a scanning laser as a reference.

In addition to the flat wear plate surfaces, the SM's can be used to machine edges, central vertical keyways, reworking Mae West Blocks, including cutting new slots and drilling and tapping.

2.0 Advantages
Time. Machining wear plate surfaces in Mill Stands is nearly always a critical path operation and time savings shorten shutdown turnaround times.

Time savings are achieved in set up time, as the Symmetrical Mill only requires a single surveyed set up to machine two Wear Plate Surfaces as against a conventional mill requiring to be set up for each surface. In addition the Symmetrical Mill design allows the use of a 16" (400mm) diameter-facing cutter. This reduces the number of passes to cover a wear plate surface to 2 and allows the mill head to be driven up one side, across and down the other side to complete a single cut covering the whole surface.

Time is typically halved relative to conventional mills allowing all four faces to be machined in the time it has taken for two.

Accuracy is increased as the faces, by definition are always parallel to each other as the machining is carried out from a common reference face (the linear rail).

The final set up can be checked by an independent surveyor, to ensure precision before machining proceeds. Set datum points are then used as by SLM and or client to prove set up is stable, saving surveyor costs and time.

A working platform which follows the cross bed up and down the window carries up to 2 men. This avoids the use of ladders and most scaffolding (further avoiding delays) and enables the machinist to closely follow the cut, which he controls with a pendant style control box.

3.0 Capacity and Shipping
Cross beds are a standard 6ft wide. This allows all column widths to be accommodated. Height is covered with two basic mill bed lengths of 10 ft and 17 ft with extensions for final size. The top and bottom frames are typically fabricated to suit the actual mill.

Shipment is typically on a flat bed truck within North America.