Profile Control

Profile Control

Profile Control - The ability to produce accurately, the intricate and often minute profiles on the cutting edges of tools and cutters is an essential requirement in tool and die making. Furthermore, if the progress of producing any form can be inspected while the form is being machined or ground, and without removing the form from the machine, a great deal of time and expense is saved.

Since tools and cutters are in the hardened condition at the stage of finish grinding, the first essential, for intricate shapes is to dress the grinding wheel with the profile required. After that it is a case of correctly applying the wheel to its work and inspecting progress.

The methods used for dressing a specific profile onto the face of a grinding wheel generally consist of either a mechanical system where the diamond is guided by a profiled template through some form of reducing pantograph or an optical system incorporating sufficient movements to build up the profile required, the progress of formation meanwhile being inspected through a microscope or on a screen.

An example of optical equipment is the 'Optidress' shown in Fig.(a). This is attached to the grinding machine or to an auxiliary head carrying the wheel and the working area is illuminated by a lamp-house underneath.

(a) The Optidress Wheel Dressing Equipment

(b) View Through Microscope

The dressing operation is viewed through the microscope, which forms the pivoting axis of the diamond. An image of the wheel and diamond profile is seen magnified x 10 against a graticule marked with concentric rings 0.5 mm apart and with 0.1 mm graduations.

By means of slides on the equipment, the diamond may be rotated through 1860 and fed in a straight line at any desired angle, the movements being controlled by graduations on the actuating screws and observed through the microscope. This combination of movements enables any profile to be built up and imparted to the wheel face.

A diagram showing the diamond against a dressed profile as seen through the microscope fig.(b). The control of the grinding operation on the profile can be supervised only by optical means, and an example applied to an operation on a surface grinder equipped with a special cylindrical grinding attachment.

The lamphouse in the lower LH comer illuminates the operation, and the image is transmitted through the microscope opposite, from where it is enlarged and transferred optically on to the large circular viewing screen. If necessary, of course, a translucent master layout can be fixed to the screen for comparison. The illustration also shows Optidress equipment fixed to the machine for dressing the wheel.