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Two versions of the Viceroy self-contained "Sharpedge" edge-tool sharpening machine were made, the now rarely-found Model 12/10-inch "Junior" and the very much more common 12/16-inch.
A horizontal rotating disc in "Aloxite" was used as the sharpening medium, this being "supported top and bottom with accurately machined flanges which ensure rigidity in use". Drive to the wheel spindle was direct from a worm-wheel gearbox, the 1/4 h.p. 1425 r.p.m. motor being held within the welded, 3 mm (12 swg) sheet-steel cabinet base. Over the years the drive system and gearbox used changed with, pre-1973, the unit used being a 10 : 1 reduction David Brown Radicon, described as a "Holroyd Type 341503" and driven by a V-belt from the motor to give a wheel r.p.m. of 110. From 1973 until 1974 the box was connected direct to the electric motor and the drive ratio changed slightly to 10.5 : 1 - the wheel speed becoming 130 r.p.m. From 1974 to 1978 an altered drive shaft was fitted and the wheel-retaining design simplified - the upper retaining plate being fitted with sloping instead of flat outer face and retained by a nut instead of being screwed on and tightened with a pin spanner - both screw-on and nut-retained types used a left-hand thread). Another change, obviously aimed at cost saving, was the replacement of the original aluminium wheel tray with one moulded in fibreglass. In 1978 the gearbox ration was changed to 13.5 : 1 and the wheel speed reduced to become 105 r.p.m. Finally, in 1981 (and the last before production ceased in 1991), yet another change was made to the wheel-holding spindle.
Simple to set up, in use the Sharpedge was an easy machine to operate: what the makers described as a "Master Arm" was used to secure the job being sharpened (a grub to adjust "squareness" was provided) with a variety of fittings available to take different tools. For rough grinding the tool was set to run against the (anti-clockwise) direction of the wheel but for fine finishing swung round to run with it. A circular scale was provided that allowed the user to set the reproduction of angles between 10 and 30 degrees.
An important part of the sharpening process was the use of honing oil - preferably one with anti-bacterial properties - this being lifted from a container within the base by a simple cam-operated diaphragm pump (driven from the spindle of the main motor) and allowed to flood (and so thoroughly soak) the wheel for ten minutes before use. As the tool was sharpened the oil supply was kept running, the lubricant flowing from a radially-disposed pipe above the wheel back into the tank by gravity and then recalculated. As the pump was similar to those used on older cars to pump fuel from the tank to engine, its flow rate was not adjustable and set by the factory to be correct for normal use.
A number of extras were available including an externally-mounted conical grinding wheel that protruded through the left-hand face of the stand. The attachment allowed the internal radius of a gouge to be sharpened and was provided with a tap to allow the honing fluid to be used and a V-shaped tool rest that also guided used fluid back into the main tank. When the conical unit was fitted, the distribution pipe to the main wheel also had a tap fitted. Also available was a machine-knife holding attachment with a capacity 10 inches (254 mm); a holder for planing machine blades; a special dressing tool for the wheel; a holder for external-radius gouges and a full wheel cover in sheet steel.
Hundreds of these machines were supplied to schools, colleges and professional woodworking shops from the 1960s until the 1990s and can often be found little-used and in perfect order at bargain prices on the second-hand market..
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