Manufactured during the 1950s and 1960s, the "396" was named after its table size - 36" x 9" - and based on principles first incorporated in the pre-WW2 Bridgeport. However, unlike many similar machines, the Town Woodhouse did not clone or even copy parts of the American machine - but was an entirely original production. Built in Mk. 1 and Mk. 2 forms both versions of the 396 were of very similar appearance - but with the later model having nearly every casting changed and its vertical head being significantly altered and improved. The layout of the miller was entirely conventional with a heavy main column, in cast iron, formed as a stiff box casting with internal bracing and incorporating a small tool cupboard in its left-hand face - and the hollow base used as a convenient coolant tank. The knee rode on ordinary V ways, was fitted with adjustable tapered gib strips and both the elevating screw, and the table feed screws with Acme-form threads running through substantial bronze nuts fitted with the ability to reduce backlash. The screws ran through particularly large end supports - containing Timken taper roller bearings - and the zeroing micrometer dials were, at 3.5 inches in diameter, of a reasonable size for the time. The table was formed with a coolant tray around its outer edge - but with the 3 T-slots running through the end sections to maximize the clamping area - and had a T-slot machined down its front face to provide a location for the adjustable knock-off stops. Travel on the standard hand-feed table was 23 inches longitudinally, 9 inches in traverse and 17 inches vertically - however, with the optional power-feed attachment in place (giving twelve rates, in geometrical progression, from 0.5 to 9 inches per minute) longitudinal travel was reduced to 19.75 inches, but with handwheels still fitted at both ends of the table.
Spigoted into the main column, the turret housing was 15 inches in diameter, graduated for rotation through 360° and clamped in place by four bolts. The cast-iron ram was round - like a pre-September 1952 Bridgeport - and could be rotated in the same way, by a handwheel operating through worm-and-wheel gearing - but required sliding in and out by hand. The ram was locked into the turret by two pad bolts and the end opposite the vertical head machined to accept a slotting attachment.
The original vertical head had hand-powered downfeed and an interesting, though noisy, epicyclic gear arrangement that provided, in conjunction with the belt drive, 10 speeds from 100 to 2000 r.p.m. or, alternatively, 200 to 4000. At 3.75", the quill travel was a little shorter than the Mk. 2 while the high/low range selector used a lever instead of a dial. Much-improved, the robust Mk. 2 head had 9 speeds, from 80 to 2420 r.p.m., and was driven by a 1-h.p. motor through V-belts and a lathe-like "backgear" assembly employing some nylon gears to ensure quiet running. Marked HIGH - LOW the backgear selector dial was conveniently positioned on the head's front face. Able to be rotated through 360° in the vertical plane about the turret overarm, both heads could also be tilted over - the mechanism for the latter being contained within a large-diameter cylindrical housing, with a degree ring engraved around its outer edge. The spindle could be raised and lowered through 4 inches of travel by either a hand lever - working through a flame-hardened pinion meshing with a rack cut into the quill - or by a fine-feed handwheel through worm-and-wheel gearing. A micrometer dial was fitted to the handwheel and a micrometer depth stop provided to aid accurate depth control. The most important improvement on the Mk. 2 head was the inclusion of power down-feed: two rates were available, working through a safety-overload clutch whose release setting was built in during assembly. Selected by a push-pull knob - and engaged by a similar control positioned beneath the fine-feed handwheel - the feed could be disengaged by hand, or automatically knocked off against the micrometer depth stop. The spindle and quill were in flame-hardened alloy steel, hardened, ground and with the quill housing honed for a perfect fit. The end of the 30 INT taper spindle was supported in adjustable needle roller bearings - the aim being to give the smallest possible radial clearance between it and the quill. A roller bearing took spindle end thrust while an upper taper- roller bearing ensured rigidity and accurate alignment. As a further contribution to smooth running, the aluminum belt pulleys were balanced. On both heads the maximum clearance between spindle nose and table was 14.5 inches.
Driven by a 0.5 h.p. 3-phase motor, the self-contained slotting attachment was carried on the back of the ram and retained against a 7-inch diameter, 4-bolt flange. It had 4 rates of stroke: 40, 60, 90 and 140 per minute. Both the main housing and the ram were manufactured in high quality cast iron - with the important gib strip in bronze and the maximum tool size 0.5 inches in square or round. Pick-off gears, arranged in pairs, and accessible under a side cover retained by round knurl-edged nuts, were used to changed speeds while the stroke length was infinitely adjustable from 0 to a maximum of 2 inches..
Well made and robust - the net weight was 1792 lbs (814 kg) - and once very popular, today a lack of spare parts limits the appeal of the 936 - though custom-made spares would still be a good investment to keep an otherwise-sound example of this most versatile milling machine running..