Continued:
Early stands (even the first under-drive version) were very compact affairs, constructed from heavy-gauge sheet-steel and very little wider or deeper than the miller's base plate. Later machines were fitted to what can only be described as cavernous stands with enormous chip trays - some of which had wings extending to the full width of the table. These latter types, whist ideal in an industrial location, are difficult to accommodate in an amateur's workshop and, as a result, many have been cut down. However, if you buy a Centec on an unmodified stands, before selecting your hacksaw blade it's worth knowing that, even through rather cumbersome, it's still possible to manoeuvre them through an ordinary doorway. All the large-stand mounted millers seen by the writer have been equipped with 3-phase electrics and a problem arises when fitting then with a single phase motor - an annoying drumming noise caused by the stand acting as an amplification box. A simple solution is to slightly pull in the left and right-hand faces of the stand by fitting a length of threaded rod between them. With a couple of nuts at each end to adjust the tension the resonance can, with a little experiment, be quickly and easily eliminated.  Rather than change the motor it is now far better to take advantage of the falling prices of 1-phase to 3-phase inverters and fit one of those instead.
The 2B/2C was also offered in modified form as the "Automil" and "Automil Duplex" both with hydro-pneumatic drive to the table; each was made in much smaller numbers than the conventional machines and, whilst the Automil is more commonly found on a heavy cast-iron stand as a conversion from the 2C, it actually began life on the ordinary sheet-steel cabinet as a modified 2B. The "Automil Duplex" must have been an especially low-volume model and was built up from standard Centec components, mounted on a wide stand, and arranged so that parts could be milled simultaneously on opposing ends. Each spindle was driven by a 1 h.p. motor, the table had 14-inches of travel, with a fast traverse in both directions, and a stepless feed rate from 1 to 400 inches per minute.  If you find a standard Automill it is reported to be (though the writer has never attempted it), a relatively simple task to convert it to manual "2B/2C" operation. Whilst the normal spindle fitting (both horizontal and vertical) for the 2B was a No. 2 Morse taper examples have also been found with a 30 INT, as specified for the 2C and Automill. Another Centec produced in smaller numbers - and one of the last machines made - was the No. 4; this was a much larger and heavier machine than the 2A and 2B and supplied as a horizontal miller only with a program-controlled and hydraulically-power 10.5" x 40.5" table with 18 inches of longitudinal movement, 7 inches in traverse and 13 inches vertically. Powered by a 1.5 h.p. motor, and using principles outlined in patents (applied for, but either not granted or pursued), the table-drive system had a stepless feed running run from 0.5 to 50 inches per revolution of the spindle with a very high thrust capacity and a 300-inches-per-minute fast-traverse. Rigid stops with micrometer adjustment collars were fitted at each end of the table to allow precise setting for dead stop and reversing - as might be used in plunge cutting - and the spindle arranged to stop automatically during rapid table returns in either direction. So that the required horizontal program could be quickly and easily set four slots in the front face of the table were used to house adjustable trip dogs and, to cope with the high rates of metal removal that were possible, one end of the table was left open so that swarf and coolant could drain away quickly into a detachable collector. The spindle was considerable strengthened and enlarged sufficiently to take a robust 40 INT fitting. It ran in three precision bearings with the one immediately behind the nose being a taper-roller bearing with an inside diameter of three inches. 10 speeds were provided, ranging from 50 to 2000 rpm, by either a 3 h.p. or 5 h.p. motor. In line with its intended industrial use lubrication was provided by a centralised, one-shot, operator-activated  system that supplied oil to both slides.
Other specialist versions of the Centec included the 3, 3R and 3P and 3RV and 3V. The 3 and 3R had programmed control of the horizontal table motion - with the R version also gaining a vertical motion to the milling spindle that made it possible to combine more than one consecutive milling operation in each automatic cycle. The 3P had the refinement of a powered vertical head movement continuously controlled by the copy template and tracer valve. Shapes with angles up to 80-degrees from the horizontal, and very slow tapers, could be accurately copied without steps. Fitted with a 34.25" x 11.75" hydraulically-driven  table (8" x 30" working area and 14" of travel) all these models were considerable larger and heaver than the maker's conventional machines. On the 3 and 3R the spindle carried a substantial 40 International fitting and was driven by a 3.5 h.p. motor with an additional 2 h.p. motor to drive the hydraulic pump. An infinitely-variable speed drive was fitted that gave a range of 50 to 1400 rpm or, optionally, 200 to 2000 rpm. The  3RV and 3V had exactly the same programme controls as the 3 and 3R but were of vertical rather than horizontal configuration. Their vertical head was of robust construction and fitted with a spindle supported in large, closely-spaced roller bearings and carrying a 30 international or No. 3 Morse taper. The head was provided with a small amount of cross movement, operated through a calibrated dial, but this was for setting purposes only. Spindle speeds ran from 73 to 366 r.p.m in low range and 366 to 2200 r.p.m. in high. These specialist Centec machines were expensive; whilst in the 1960s a 2B on a stand could be had for a modest £455; the 3R was a massive £3250 - more than twice as much as Smart & Brown's best toolroom lathe, the 1024.   Besides the machines mentioned Centec also manufactured a range of milling machine accessories including indexing units and quick-action swivel base vices, a "Senior" router for wood and non-ferrous metals, profile (tracer) controlled millers, auto-pneumatic indexing tables and could offer complete rotary-transfer machines built to a customer's specific requirements. They also appear to have had a hand in either the development or production of the "Omlor 70", a high-precision single-spindle automatic lathe advertised for a time during the early 1950s. The lathe incorporated automatic backlash elimination and was able to produce complicated profile parts as well as shafts, bolts, screw and nuts of the kind commonly used in the watchmaking, optical, electrical instrumentation and similar industries.
Whilst the 2A and 2B are the most commonly encountered models any type of Centec miller is difficult to find. The "C is especially rare as are the specialist machines which, once their productive life was over, would have been unceremoniously scrapped. The Centec miller, in all its forms, remains a remarkably useful tool - and because there is nothing on the market today which combines the compactness, versatility and quality of this lovely machine, they are highly sort after on the second-hand market.
If you have an unusual Centec of any type including the router - or any sales literature showing the side-countershaft models - the writer would be interested to hear from you..

Centec 2C. The rarest of the conventional Centec millers, the 2C, was fitted to a massive cast-iron stand and, in addition to its larger compound table, also had a wider and much heavier main column and very much more substantial knee. Note the 4 holes in each corner of the massive base - these are tapped 1" Whit to take eye bolts for lifting. The miller must not be lifted on the overarm or round the column - the weight of the base will rip out the 3/8" Whitworth bolts that hold it to the column.

Table power feed arrangement showing the dog-face pick-off gears that could be arranged to vary the rate of feed. The spare gears were stored in the slot in the left-hand side of the housing.

Early table feed screws were 1/2" x 10 t.p.i. square thread, later changed to a more robust and longer-lasting 5/8" x 10. t.p.i. - though the thread remained square. Feed-screw nuts on tables fitted with the quick-action, rack-and-pinion lever-operated feed were of the "half" type and, being pivoted and fitted with a cast-in handle, could be quickly dropped into and out of mesh..