Surface Grinder

Overview

A surface grinder produces flat, parallel faces on hardened metal to tolerances that milling and turning cannot hold. A fast-spinning abrasive wheel skims a few microns off the work each pass while the part moves back and forth beneath it. Because the abrasive cuts with thousands of tiny edges rather than one tool point, it machines material too hard to cut conventionally and leaves a finish measured in tenths of a micron. This machine is a horizontal-spindle, reciprocating-table type: the work clamps to a Electromagnetic Chuck on a hydraulically driven Reciprocating Table that traverses under a fixed-height wheel.

Everything bolts to a heavy Base, Column & Ways. The cast iron base and column damp vibration, while the hardened, hand-scraped ways set the geometry that the whole machine inherits, any error in the ways prints straight onto the work. The cutting is done by the Grinding Spindle Head, a precision motorized head carrying the wheel between balanced flanges.

How it works

The operator sets a ferrous workpiece on the Electromagnetic Chuck and energizes it; the electromagnetic field clamps the part flat with no protruding hardware to foul the wheel. A demagnetizing cycle releases it afterward. The Grinding Spindle Head runs the wheel at constant surface speed, and the Hydraulic Power Unit drives the table back and forth: oil enters a cylinder, strokes the table to a reversing dog, and a pilot valve flips flow to reverse it. The hydrostatic ways carry the table on an oil film so it glides without stick-slip.

Between table strokes the Saddle Cross-Feed indexes the saddle sideways by a set increment, stepping the wheel across the work until the whole face is covered. The Vertical Down-Feed then lowers the wheel a few microns and the cycle repeats until the part is ground to size. A flood of fluid from the Coolant System system carries heat and swarf away, critical, because local heating would distort the very flatness the machine exists to create.

As the wheel wears and loads up, the Wheel Dresser passes a diamond point across its face to true the profile and expose fresh abrasive. The Control & Display sequences spindle start, chuck magnetization, table traverse and feeds, and a guard set contains the wheel and retains coolant spray.