email: tony@lathes.co.uk
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S.A.B.C.A. Precision Universal
Milling Machine Type J.R.C.2


Manufactured during the 1950s by S.A.B.C.A. (Société Anonyme Belge de Constructions Aéronautiques) of Belgium, the Type J.R.C.2 Universal Milling Machine is, compared to the very common and popular German Deckel, Maho and Thiel* versions of the design, a very rare, seldom encountered. Built under licence from a Mr. J.R.Cuttat - who must, presumably, have been the patent holder and this his second design (hence J.R.C.2) - like others of its type this was ingenious, adaptable and versatile miller that leant itself to the solving of a multitude of machine-shop problems. The secret of the type's success lay in it being able to mount a number of different heads - horizontal, vertical and slotting - in combination with various types of table bolted to a T-slotted vertical surface on the knee. Constructed in an ingenious way, the layout of the spindle-drive system and head assembly was both compact and efficient: the top of the main column was machined as a slideway to carry a separate housing - able to be moved forwards or backwards by a large handwheel (a capstan handle was used on early models) working through a skew drive gear and captive spinning nut. The sliding head was arranged to mount a horizontal milling arbor and overarm while also acting as a base to carry, on its front and driven from the horizontal spindle, vertical milling or slotting heads. Because the only in-and-out feed was on the head (the table assembly moved sideways and vertically) to solve the problem of how to drive the spindle when its housing was moved, a system of quiet-running, twin V-belt drives was used (the usual method on this class of miler being to use gears). Power came from a 2-speed, 2.2 kW (3 h.p.) motor flange mounted against the back of the column that carried on its shaft a 3-step, twin-V-belt pulley (thus facing the operator with having to move two belts across for each speed change). The drive then ascended to an high/low speed gearbox with an output shaft that carried a sliding twin pulley able to move as the driven shaft above travelled with the ram. To double the number of speeds available for the vertical attachment, a further 2-speed gearbox was built into the forward end of the sliding head. The result was a range of 12 speeds for the horizontal spindle in two sets from 48 to 942 r.p.m. and 144 to 2862 r.p.m., and an impressive 24 for the vertical head that spanned 48 to up to 6552 r.p.m. - a range wider than any offered by any rival.
In order to provide adjustable stops to limit the head's travel, a T-slot was machined into the left-hand face of the column, immediately below the head, with a cast lug on the latter used as the abutment.
Although the basic mechanical design of the S.A.B.C.A. followed that of the traditional
Precision Universal Milling Machine, it lacked the usual wide range of accessories listed by other makers. Only two tables were offered for bolting to the (750 x 280 mm) vertical surface: one, generously proportioned at 760 x 240 mm, could be that tilted 90° left and right from vertical while the other, a 720 x 200 mm "Universal", was able to be tilted and pivoted. Side to side movement of the table was 320 mm and vertically 340 mm, the elevation being such that the table could be brought right up to touch the horizontal arbor. Driven by a single V-belt that took its drive from the spindle countershaft assembly and controlled by a gearbox bolted to the right-hand face of the column (with its output drive sent through a universally-jointed and splined shaft) 12 rates of feed were available, longitudinally and vertically, from 3 to 264 mm/minute. Picking up the drive on the end of the table was a reversing gearbox, connected to the table's feed screw through a safety clutch. Hand feed in the horizontal plane could be by screw or a quick-action, capstan-handle-controlled, rack and pinion drive - the screw-to-nut connection being released very easily by a lever set behind the table at its left-hand end. To lift the table by hand, the operator could select - using a gearbox mounted on the handwheel shaft - a slow rate of either 1 mm per revolution or (very handily) one must faster for quick positioning.
Continued below:

S.A.B.C.A. Type J.R.C.2 miller with  a powered dividing head mounted  on the table

Continued:
Just one plain vertical milling head was listed, with a No. 4 Morse taper nose and a 20 mm spindle bore. Running in high-precision taper roller bearings and hardened and ground all over, the spindle assembly was beautifully made but lacked a quill feed. Most competing makers at the time offered optional, very high-speed, self-motorised heads that incorporated, most usefully, both fine and rapid-action drilling feeds. However, the unusually large number and range of speeds did go some considerable way to compensate. Mounted on the end of the sliding base, the upper ram had 140 mm of in-and-out travel under the control of a handwheel.
As carefully configured as the horizontal, the vertical spindle was also hardened and ground and ran in super-precision bearings. Built around a particularly stout main column with wide and generously-proportioned ways to carry the knee, the miller was mounted on a separate cast-iron stand - whose chip tray was, unfortunately, small and ineffective.
An owner writes:
Thanks for the tech spec on the Sabca Mill that arrived today, which is of much interest. My own is nearly identical to that shown, the only difference being a 4-spoked lever arrangement for the Y axis travel instead of a handwheel and a slightly different shape of door to the lower end of the machine.
I bought it for £400 a number of years ago from a fellow model-engineering club member. I know little of its history, except that at some time the original 3-h.p., 3-phase phase, 2-speed motor had been rewound to single phase. This was not a success as it certainly did not like the normal domestic mains. Also, the original 2800 and 900 motor rev arrangement that gave a very clever range of speeds,( 12 horizontal or 24 vertical evenly spaced) was now left with huge gaps between the speeds on the 1-speed 1425 r.p.m. motor. I was given a 2800/1425 motor that I ran through a static phase converter. However, even using the two motor speeds it could not be called a success and the motor eventually failed.
At some period of it's history the machine had suffered it's fair share of abuse with obvious signs of damage to the table and I felt no sense of guilt it attempting to update it, rather than restore it to its ex-works condition (which, given a normal domestic electricity supply was not practical anyway). So, I splashed out. I went for a new 3-phase motor, plus a modern inverter and have the best of all worlds. I leave the twin V-belts on the middle speed. I can also use the gear change for horizontal mode, or a combination of both gearboxes for vertical milling. I now have the original speed range, with no steps, and plenty of torque at the lower end.
I have also fitted digital read-out on all 3 axis and a halogen work-light. Unfortunately, the maker's plate has gone, so I cannot date the machine, although I would love to have some rough idea, and also what it cost. Not cheap, I would think.
I am really delighted with the end result. A most versatile machine, beautifully made, that is a solid as a rock, runs very sweetly and is very accurate. I suppose with the inverter and the digital readout system, plus a few extra collets, it stands me at about a £1000, and worth every penny. I am getting a bit long in the tooth now and, having been brought up on well-built machine tools, am biased - but I do believe that money spent on good second-hand British (or American or European) tools is better value than on many of the Far-eastern imports.
*Proof of the type's success - the genus Precision Universal Milling Machine - is evident from the number of similar machines made in various countries including:
Austria:
Emco Model F3
BelgiumS.A.B.C.A. Model JRC-2
CzechoslovakiaTOS FN Models
England: Alexander "Master Toolmaker" and the Ajax "00", an import of uncertain origin.
Germany: Hahn & Kolb with their pre-WW2 Variomat model
Wilhelm Grupp Universal- Fräsmaschine Type UF 20 N/120
Hermle Models UWF-700 and UWF-700-PH
Leinen Super Precision Micro Mill
Macmon Models M-100 & M-200 (though these were actually manufactured by Prvomajska); Maho (many models over several decades)
Ruhla
Rumag Models RW-416 and RW-416-VG
SHW (Schwabische Huttenwerke) Models UF1, UF2 and UF3
Thiel Models 58, 158 and 159
Wemas Type WMS
Italy: C.B.Ferrari Models M1R & M2R
Bandini Model FA-1/CB and badged as Fragola (agents, who also sold a version of the Spanish Meteba).
Japan: Riken Models RTM2 and RTM3
Poland: "Avia" and "Polamco" Models FNC25, FND-25 and FND-32 by Fabryka Obrabiarek Precyzyinych
Russia: "Stankoimport 676"
Spain: Metba Models MB-0, MB-1, MB-2, MB-3 and MB-4
Switzerland: Aciera Models F1, F2, F3, F4 and F5
Christen and Perrin Types U-O and U-1 (Perrin Frères SA, Moutier)
Hispano-Suiza S.A. Model HSS-143
Luthy
Mikron Models WF2/3S, WF3S, WF-3-DCM & WF-2/3-DCM
Perrin Type U-1
Schaublin Model 13 and Model 22
The former Yugoslavia: Prvomajska (in Zagreb with Models ALG-100 and ALG200)
Sinn Models MS2D & MS4D
"Comet" Model X8130, imported to the UK in the 1970s by TI Comet.
United States: Brown & Sharpe "Omniversal"
Sloane & Chace in the USA produced a miniature bench version and at least five Chinese-built models have also been made, including one from the Beijing Instrument Machine Tool Works. A number of the "clones" merely followed the general Thiel/Maho/Deckel concept whilst others, like Bandini and Christen, borrowed heavily from Deckel and even had parts that were interchangeable. Should you come across any of these makes and models all will provide "The Deckel Experience" - though you must bear in mind that spares are unlikely to be available and, being complex, finely-made mechanisms, they can be difficult and expensive to repair..

Spiral milling in progress

Gear cutting using the horizontal arbor. Note the handwheels to lock the overarm and drop bracket

Slotting Head mounted and the Universal Work table tilted and inclined


S.A.B.C. A. Precision Universal Milling Machine Type J.R.C.2

On the right the table-feed gearbox driving via a universally-joined and splined shaft to the table's reversing gearbox and clutch unit.
Top left can be seen the handle to select the fast and slow speed to the vertical head

Generously proportioned table and the inclined, 24-speed vertical head

Capstan handle to drive the quick-action left-to-right table feed

3-step, twin V-belt pulley on the motor shaft

Twin V-belt pulley, able to slide along its shaft as the driven pulley above moved with the travel of the overhead ram


email: tony@lathes.co.uk
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S.A.B.C.A. Precision Universal
Milling Machine Type J.R.C.2