Have you ever wondered how those fine diving lines were engraved on various parts of a machine tool, especially on large-diameter sloping surfaces? Here might be the answer...
Manufactured during the 1950s and 1960s by Abwood Machine Tools of Princess Road, Dartford in Kent, the Abwood Automatic Universal Circular Dividing Machine was a self-contained unit intended for both toolroom and production use. Claimed by the makers to be "easy to set up and completely automatic in operation", once configured as required and running, the Abwood could engrave fine lines on a variety of flat, vertical and angle-faced workpieces.
Although automatic operation was its intended function, the machine could also be used manually where unique jobs had to be tackled, a large handwheel being fitted to the machine's left-hand face for this purpose. In its standard form, the machine would engrave all the commonly found English, metric and degree systems, though if others were required, for special applications, the factory could provide these as well. Built into the machine as part of its standard specification were 360 and 200-tooth master division rings - the former able to produce a maximum of 2880 lines and the latter 1600 - the makers also offering to manufacture any master that a customer might require. Indexing was by what could be called a "direct" method from the master, there was no train of gears - and hence backlash - to upset the accuracy. 
Work was held on a rotary table provided with four radial T-slots and a central hole bored to take a hardened and ground steel spigot, work being aligned with this and checked by the use of a dial indicator mounted on ground steel bar set to one side of the table.
The cutting tool - which could be a single-point type in high-speed steel, tungsten, carbide, diamond or an electric etcher - was held in a holder able to be swivelled through 90° each side of vertical; hence, it was possible to engrave not only flat and vertical surfaces, but also any part with a flat, convex or concave form. Drive to the tool slide head was by a simple ratchet feed, the final drive being through rack-and-pinion gearing - the assembly being equipped with a lever that disengaged the mechanical drive and allowed the slide to be moved by hand.
For safety - and to prevent spoiled jobs - the Abwood was fitted with an electrically operated, pre-set counter that stopped the machine when the number of lines to be engraved had been reached. Once stopped, it was not possible to restart until the counter had been reset.
Line lengths (to a maximum of ¾") and their sequence (long, longer, short, shorter, etc.) were governed by adjustable cam stops, the drive for this mechanism being contained in an oil bath with shafts running in ball bearings. To govern the line-length sequence, a turret unit was used that could be fitted with either ten or twelve stations.
Drive came from an electric motor combined with a speed-reduction gearbox (fitted with a manually-operated clutch) held within the cast-iron cabinet stand and switched by a No-volt release push-button starter.
The extract below, from a 1958 catalogue, gives the full specification and further technical details of this finely constructed machine tool.