Varying considerably in output according to the size of the machine, the motor was mounted on an adjustable plate within the base of the main column. On the very earliest machines, a choice was offered between drive by an oil-lubricated "silent chain" and four V-belts; in the event the latter proved by far the more popular and the chain option quickly disappeared from the catalogues.
In addition to the expected arbors and cutters, a very wide range of extras was offered - though the full range was not always available in every decade and contracted sharply during the 1960s. Included were seven different types of vertical head and attachments and accessories for: powered slotting; dividing and indexing together with an enclosed gear-driving attachment and suitable raiser blocks to increase capacity; rack cutting and indexing, gear cutting, power and hand-driven circular milling; powered universal spiral milling; plain, swivel and tool maker's vices; quick-change tooling adaptors (later made standard); a cap-type intermediate arbor support for mounting between cutters; cam milling with hand or power feed; keyway milling; a special "wide-range" dividing head (that could also be applied to a stand unit) that gave divisions from 2 to 400,000 and any angle at intervals of six seconds without the need for changewheels or other than the standard indexing plate; a range of factory-fitted precision measuring equipment of the traditional type to hold length-rods and slip gauges; a right-angle drive attachment with a forward pointing handwheel that drove the table longitudinally to allow the operator to closely follow the contour of a die; an electric coolant pump (in place of the standard gear-driven type) with the necessary piping and, finally, for the vertical head, power and rapid feeds in both directions and a four-position turret stop.
Late-model Dial Type milling machines
Before the introduction of the heavily revised versions (with separate column and knee dials) the sizes 2, 3, 4 were fitted with electrical push-button control of spindle start, stop and speed selection - and so removed the need for the traditional clutch lever or starting handle as Cincinnati termed it. The push buttons were arranged along the front edge of the saddle and duplicated on the left-hand side of the column - with a further set of controls on the right-hand side to start and stop the spindle, switch the coolant on and off and electrically isolate the machine.
Manufactured from the mid 1950s onwards - but at first only as the new and larger No. 5 and No. 6 machines and as High Power and Dual Power versions of the others - the last models of the Dial Type series were heavily modified mechanically, with an improved specification - and hence the standard (lower-speed) model was dropped. The High Power and Dual Power models had twenty-four spindle speeds (in a 100 to 1 ratio) spanning 16 to 1600 r.p.m on the No. 3 and No. 4 models and 14 to 1400 r.p.m. for the No. 5 and No. 6. Ordinary types were also improved and equipped much as the former High-Speed models with 16 speeds from 16 to 1600 r.p.m. (4 r.p.m. slower and 300 r.p.m. faster than before) and an increase in the number of feeds from 24 to 32 with a range that spanned from 3/8-inch to 90-inches of travel per minute. However, not all machines were equipped as per the catalogue specification and ordinary models of this era have also been found with twenty-one speeds spanning 20 to 1500 r.p.m on the No. 2 and 18 to 1300 r.p.m on the No. 3 and No. 4. With these improvements the Dial Types were now all capable of tackling not only a wider range of jobs, but also at faster rates of metal removal.
In 1959, after the new design of knee and column spread to the all types Cincinnati changed the Model numbering to one that (in the writer's opinion) had little merit. In contrast to the former very simple designations the revised set listed the machines as the Model LL and attempted to categorise them by specification using two and three-digit codes. For example, the No. 3 became the 315-15 - where the first digit indicated the table length (3 for 34 inches, 4 for 44 inches, etc.), the second pair the spindle-drive motor horsepower (15 for 15 h.p.) and the last two the table width (15 for 15 inches). The new range comprised: 315-15, 415-15, 420-16 and 520-16; in other words, respectively, the Models 2, 3, 4 and 5. In compass with these revisions the High Power models were re-listed in an identical manner the Model ELA with sizes of: 520-20, 540-20, 620-20 and 640-20.
Automatic Table Cycle
A new option, introduced in the mid 1950s on most Cincinnati plain horizontal and vertical models (but not the universal) was automatic table cycle control: this enabled an operator to set up, using specially-shaped trip dogs in a just single T-slot on the table's front face, a sequence of simple but fully or semi-automatic operations that included all aspects of table control including movement direction, feeds and rapid traverses. When fitted with cycle control the individual levers used to operate the table feeds were abandoned and replaced by a single-lever jockey control with "stop" at 5 o'clock, rapids selected left and right at, respectively, 10 o'clock and 2 o'clock and feeds similarly positioned at 8 o'clock and 4 o'clock.
Three additional controls could be added to the table cycle system, all built into the machine when new: Automatic Spindle Stop, Live Rapid Traverse and Automatic Knee Retraction. Whilst the Automatic Spindle Stop was just a simple (factory-installed) option to extend the usefulness of the automatic table cycle, Live Rapid Traverse was a more complex mechanism that provided an over-riding action built into the rapid-traverse mechanism. This, once selected, allowed the operator to set the position of the rapid feed trip dogs quickly and accurately by first mounting them in approximately the right place, starting an automatic cycle and then, when the cutting cycle engaged, using the rapid traverse lever to jog the workpiece close to the cutter. At this point the sequence was stopped, the dog set snugly against the cycle control lever and locked in place. The Automatic Knee Retraction system ensured complete safety during auto-cycle work by retracting the knee by 5/8" as the 'rapids' operated and returning it to the previous position immediately afterwards.
Fitted as standard was an Arbor-Loc spindle nose that allowed a speedy change of tools to be made whilst offering just as much rigidity as before. The Arbor-Loc also largely eliminated the need to use arbor draw bolts, a boon on vertical heads, where safety was thus greatly enhanced.
In the early 1960s a different Dial Type, the ELR, was introduced alongside the established models. Available as the 207-12 and 307-12 these had, as standard, controls at the front only (rear controls were extra) and reverted to simple lever instead of push-button operation. Available in the usual horizontal, universal and vertical types, the model can be instantly recognised if fitted with rear feeds - the sockets for the two detachable crank-handle being reversed in comparison with the older machines such that the one nearer the front was set higher than the other. .