Although in the closing years of the company's life Beaver made a range of computer-controlled milling machines (amongst others the Slo-Syn, VC35, NC5, NC5-S, NC5-ATC, NC15, NC25, NC35 and ) they are better known for their best-selling and widely exported conventional millers, the  Mk. 1, Mk. 2, V, VB, VBRP, PAL and Mk. 5 turret types. Very much larger and more substantially constructed machine than the original 1940s designed round-ram Model "A", the later models were intended for serious industrial use on the shop floor, not the toolroom or experimental department. The model-identification system used on the millers was confusing, with the un-named "MK. 1", followed by the "Mk. 2" this also being listed as the "V", "VB" and VBRP - all identifiers used casually in brochures and manuals. However, this need not be a concern - those particular models had few really significant mechanical differences that the one Operation, Maintenance and Parts Manual issued covered them all, including the 1968 PAL, a cheaper version with a lighter vertical head. A rather different machine was the Mk. 5 miller, this being a considerably updated version for which a separate publication was issued.  Operation and Maintenance data for other models can be found here
When Balding Engineering introduced their new Bridgeport-like machine, in 1957, the family firm had a 14,000 sq. ft. factory and just 40 employees but, with the success of the new machine, the site eventually grew to cover 90,000 sq. ft. with 320 people on the payroll. During 1966 it is known that Balding sent over 700 machines to America alone (making them England's largest exporter of millers to the USA) with projected sales of over 1000 for the following year. The 8-speed (later optionally 10-speed) Mk. 1 was almost identical to the Mk. 2 (illustrated on these pages) except that its head was fitted, at first, with the now obsolete 30 I.S.T. taper with an International 40 (INT40) available at extra cost. Later models (including the very common Mk. 2) are found with various fittings including  INT30,  INT40 - or even the Bridgeport R8 type and there were also small differences in the quill and feed mechanisms. The Mk. 1 was also restricted to tables of  48 and 56 inches in length with cross feed travels of either 12 or 18 inches. Although the following notes apply to the Mk. 2 machines they can also be applied, in general terms, to the Mk. 1 and the 1968 PAL model, the latter a cheapened version with a vertical head of simpler construction.
Mk. 1 machines suffered from an unfortunate flaw, the saddle guideways was placed on the centre line of the knee, so requiring the feed screw to be mounted at the side where it created a small sideways thrust. This error was corrected on the Mk. 2 by the designer, Richard Prime, the new model being listed as the VBRP with VB for Victor Balding The Company's owner) and RP for Richard Prime (it is reported that the PAL was named after VB's golden retriever, some machines having the image of a dog, Prince Hunter,  incorporated into the logo.
Standard machines were normally supplied with either a 2 hp or 3 hp motor although, if required, a two-speed motor with 1 and 2 hp on each speed could be fitted at extra cost. Occasionally machines are also found with a 1.5 h.p. motor (though these were never, to the writer's knowledge, advertised) and may well have been intended for use in training establishments or simply for lighter-duty work. Either eight or ten spindle speeds were provided arranged in high and low ranges from 70 to 375 r.p.m. and 570 to 3000 r.p.m. respectively. The initial drive from the motor was by a 4 or 5-step V-pulley to an intermediate pulley fastened to the bottom of which was a toothed pulley. A toothed belt then took the drive to the top of a "backgear" assembly with hardened, oil-immersed gears and then, via a six-spline sleeve, to the spindle. All the pulleys - and the shafts with the main drive gears - were dynamically balanced for smooth running. A variable-speed head complete with a tachometer was also eventually made available and a picture of this unit can seen (mounted as the centre unit of 3) lower down on this page. The hard-chrome plated quill ran in precision angular-contact bearings with its 5 inches of travel under the control of a fine-feed handwheel with micrometer dial, a lever-operated quick feed and power through a safety clutch in both up and down directions. Three rates of power feed were available: 0.0021", 0.0045" and 0.0086" with an automatic knock off fitted to the down feed only. Beaver also built a 4.5" x 20" backgeared, screwcutting lathe of conventional design but robust construction. of which details can be found here.
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Fitted as standard was a 30 International taper nose -  but most customers chose the optional 40 Int.  as being more in keeping with the machine's weight, size and metal-removing ability. The head was connected to the end of the heavy box-section ram by a compound joint, enabling it to be swung on the central axis of the main column, tilted though 180 degrees in the longitudinal plain and "nodded" through 45 degrees from the vertical both forwards and backwards - the latter two movements being controlled by worm-and-wheel gearing - whilst to return the head to a central position two hardened and screwed dowels were provided, one for each main axis of tilt. The head was securely clamped by six bolts passing through it longitudinally (three from each side) and four in traverse, The ram, which could carry a slotting head at its rear ready to be swung into action, had 15 inches of rack-and-pinion driven travel and sat either directly on top of the column or fitted to a raiser block of 4, 6 or 8 inches in thickness.
Over the years four different tables were offered, all 10" wide but with lengths of 36",  44",  48" or 56" and longitudinal travels of 16",  24"  28"  and 36" respectively - however, when fitted with the optional rapid-return mechanism the feed lengths were all reduced by 2". The cross traverse on the Mk. 1 was a useful 12", but on later versions of the Mk. 2 this was increased to 14.5" and 18", at extra cost, of course; the vertical travel was 19" with the standard single-elevating screw and 19 inches with the optional double-screw unit. Where fitted, what appear to be plastic handles are, in fact, ebonite. The maximum clearance between the spindle nose and table of 17". The finish-ground table feeds screws (that could also be supplied hardened) were manufactured in the company's own works (many milling machine makers bought theirs in from specialist suppliers) and the longitudinal screw ran through well-spaced double nuts. Both screws were fitted with backlash eliminators that allowed the machine to be used for the normally-to-be-avoided "climb milling" technique where the workpiece is drawn under the cutter in the same direction as the table feed instead of against it. The saddle-to-knee contact area was a usefully large 105 sq. ins and this figure, combined with the square ways enabled the makers to claim that the machine was ideal for hydraulic copying duties. At some point in model's life, probably during 1966, the design of the cross-slide ways was changed with the central raised section (as also used on the very early Model A) being moved to the right-hand side. The table was driven through worm gearing from a 0.33 hp motor and provided with 9 rates of feed from 0.4" to 12.6" per minute on 50-cycle power and from 0.72" to 15.8" per minute on 60-cycle. The feed rate was changed, as on all earlier Beaver millers, by removing a panel and changing over pick-off gears that were secured to their shafts by quick-release retaining springs. Sometimes optionally, and at other times due to specification changes, feed rates of 0.5" to 4.5" and 1" to 9" per minute were also available. The "rapids" motor returned the table at 100" per minute on 50 cycle power and 110" per minute on 60 cycle.
Some points of interest from an experienced owner:
The angular contact bearings in head and on leadscrews, etc., are all imperial sizes. Feedscrews can wear almost to the point of collapse while showing just 0.003" pitch variation along their its length (Just finished making a new set. Not too hard...)
A special oil/grease gun with a conical nozzle is required for the spindle and backgear bearings; it may be that Adams Lube Tech in Coventry can supply.
Lubrication points for the spindle bearings are in the side of the quill and accessed through a cap on the right-hand side by raising and lowering the quill (grease was specified).
The head knuckle and knee height adjustment requires the use of two sizes of 16-point 90° spline handles or spanners. If the knee handle is present, ensure that the other one is too….
An ISO320 gear oil is used in the often overlooked backgear (speed-reduction box). Neglect can cause the pinion to wear or crack. 
Although the power downfeed is similar in work capacity to that on a Bridgeport, it cannot cope with much more than a 3/8" drill and only works in the downward.
Quill return springs can be reconditioned by straightening, re-drilling, re-tempering and then rewound..

Standard head was joined to the ram end of the ram by a compound joint, enabling the head to be swung on the central axis of the column, tilted though 180 degrees in the longitudinal plain and "nodded" through 90 degrees in the traverse. Either 8 or 10 spindle speeds were provided arranged in high and low ranges (working through a "backgear" with hardened, oil-immersed gears and belt drive) from 70 to 375 rpm and 570 to 3000 rpm respectively..

The ram, which could carry a slotting head at the opposite end to the milling head, had 15 inches of travel and sat either directly on top of the column or fitted to a raiser block of 4, 6 or, as illustrated, 8 inches thick.

The finish-ground table feeds screws (that could be supplied hardened) were manufactured in the company's own works. The longitudinal screw ran through well-spaced double nuts that acted as backlash eliminators allowing the machine to be used for the normally-to-be-avoided "climb milling" technique. The saddle-to-knee contact area on the Mk. 2 was a usefully large 105 sq. ins.

A special-purpose miller set up with three heads (the middle fitted with variable-speed drive and a rev counter as used on the VBRP model) and designed for use with hydraulic control for 3D work.

Grinding the table feed screws.
The screws were all made in-house and finish ground. Where extra heavy-duty use was likely the option was offered of hardened screws.

An early Mk. 2 with a raised way on the top of the knee and a simple "bar" or "stick" measurement system in place--this unit consisted of a channels bolted to the sides of the tables in which sat accurately made rods impinging on micrometer barrels and dial test indicators. To save the delicate dial indicators from accidental damage they were fitted with hinged metal covers.

The hard-chrome plated quill ran in precision angular-contact bearings with its 5 inches of travel under the control of a fine-feed handwheel, a lever-operated quick feed and power in both up and down directions with three rates of feed: 0.0021", 0.0045" and 0.0086"; an automatic knock off was fitted to the downwards feed only.