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Elliott Omnimil 00
Junior Omnimil & 181 Horizontal

Elliott Millers Home Page  Omnimil 00 Page 2

A Manual is available for the Omnimil

Elliott's smallest milling machine was the simple but well-built and tough 181 horizontal, a model limited in appeal by being available with just a hand-feed table. However, the Company were quick to develop the machine, offering first the "Juniormil" - with a power-feed table attachment - and then, fitted with a vertical head, the "Junior Omnimil". Later versions dropped the "Junior" prefix and were known simply as the 181 Horizontal and Omnimil 00. Although the sliding, swivelling and rotating head may not have been the most rigid of structures for vertical milling - and its capacity to rapidly remove metal was definitely inferior to that of a similar-sized machine with the head more tightly integrated into the main column - its design enabled the machine to tackle an amazing variety of jobs. Indeed, it transformed a rather ordinary horizontal miller into what some users have claimed to be the most versatile yet compact machine for the smaller workshop. The vertical head, similar to that used on the earlier and original Beaver turret miller Mk. 1, was also employed on other products of the Elliot group including very late versions of the Centec 2B, these being marketed using the "Gates" label.
Using a combination of V-belt and gearing, the drive system was listed with various 0.75 to 2 hp 3-phase motors mounted inside the cabinet driving via a 4-step pulley to a simple 2-speed gearbox (with single-lever control) built into the main column. The main (reversible) motor was switched by a push-button "no-volt release" mounted on a panel neatly arranged on the front of the miller from where, on the later models, the table feed direction, vertical-head electrics and coolant pump were also controlled. On the first version of the machine, the Juniormil, made until approximately 1964 and fitted with a 1 h.p. motor, the need to group the controls together was solved by the unfortunate and dangerous method of mounting them away from the operator's normal working position on the left-hand face of the column.
A total of 8 horizontal spindle speeds was available (100, 150, 225, 300, 500, 760, 1120, and 1700 rpm) or, to special order and fitted with a 1000 instead of 1425 rpm motor, a slower range from 65 to 1125 rpm. The horizontal spindle, made from ground-finished, nickel-chrome steel, ran in precision taper roller bearings whilst the 1-inch diameter cutter arbor was a high-quality unit, constructed from a heat-treated, nickel-steel forging and supplied with a set of lapped spacing collars. The arbor was held in the No. 3 Morse taper spindle nose by a 1/2" - 13 UNC threaded drawbar; the maximum distance from arbor to table was 14 inches. Later machines used the more robust 30 INT taper in the horizontal spindle an improvement that, unfortunately, precluded interchanging tooling with the vertical head that remained a No. 3 Morse. Unfortunately, being an older design, the supporting overarm was just a 2.25-inch diameter steel bar - although the presence of the turret head did, in any case,  rule out the use of a more rigid, top-mounted dovetail assembly.
The "Junior" Omnimill had a 28" x 7" table (Juniormill 28" x 7") with power feed by means of a belt-drive take off from the top horizontal spindle pulley through a telescopic shaft to a 3-speed feed box built into the saddle. The drive could be engaged and disengaged through a "drop-worm" that connected the drive to the table's feedscrew - with  selection by a simple push-pull lever.
With three 7/16" T slots, and moved through 18" longitudinally and 6.25" in traverse, the table was arranged with coolant drain sumps at both ends - but with the T slots running right through them so usefully extending its working area. As an unforgivable economy, the makers supplied only one handwheel, normally fitted at the right-hand end of the feed screw; however, the operator could, if he desired, change it over to the other side. Later machines were fitted with a self-contained, electrically-driven table-feed unit as standard - although it is possible that some customers may have specified machines for delivery without. The table motor drove first through a pair of spur-type reduction gears, then through a series of operator-changed pick-off gears that were neatly (if inconveniently) stored in pockets in the rear cast-aluminium (later fibre-glass) belt cover. The final drive was through a worm-gear reduction that bore directly against the table's feed screw. Eight different rates of feed (from 1 to 9 inches per minute) were available and, because the drive was independent of the spindle, any could be selected in combination with each spindle speed. An automatic, adjustable trip-out was fitted to the table that disengaged it in both directions of travel. The modified drive allowed later machines to have a traverse travel of 7.5", though the longitudinal travel (and vertical travel of 12") both remained unchanged. Marked in 0.002" (0.04 mm) divisions the zeroing micrometer dial on the longitudinal feed differed from the others - their graduations being at 0.001" (0.02 mm) intervals.
Whilst both the longitudinal and cross feeds were fitted with finely adjustable tapered gib blocks, the knee to column fitting was a plain strip whose clearance was set by a line of ordinary grub screws.
Mounted on a round support beam carried in a casting spigoted into the top of the main column, the 3.5"-travel quill-feed vertical "Omnimil" head was a self-contained V-belt drive unit driven by a 3/4 hp 3-phase motor. The motor was fitted with a double pulley that drove forwards to an intermediate 4-step pulley - thence then to a 4-step pulley on the main spindle with the drive protected by a cast-aluminium (later fibre-glass) cover with a section at one side that could be hinged open. By juggling the belt positions a total of 7 speeds were obtainable - from 200 to a usefully high 3600 rpm (4360 rpm on 60 Hz) - a rate of rotation that also allowed the machine to be pressed into use as an accurate co-ordinate drill. Although the quick-action feed of the head was well arranged, with a depth stop and adjustable spring tension, one unfortunate drawback was the lack of a fine-feed mechanism for the quill.
Although a compact machine, the 181 was very heavily built with the complete base and chip tray constructed in cast iron; the approximate weight, complete with the Omnimil head, was 1624 lbs. It stood 69 inches high and occupied a space 38 inches deep and 38 inches wide. Advertised accessories  included Elliott's smallest dividing head, the 4-inch, a universal milling attachment (without quill feed) and a slotting attachment - both to mount on the horizontal spindle socket - all-steel plain and swivelling-base machine vices, two sizes of Elliott-branded, collet-type cutters holders, a Model B boring head, open and closed tool cabinets, optical measuring equipment, cutter guards, low-voltage lighting, a 6-inch rotary table and a Hydraulic copying attachment that was able to produce 3D work using the "scanning" or "die-sinking" method.
Weights appear to have varied from catalogue to catalogue - with some having an enormous difference between the net and gross figures. However, on an Avery crane scale a bare 00 machine, date stamped 1968 with its table motor, round overarm and arbor bracket in place in place was found to weight 1372 lbs..

The 7-speed sliding, swivelling and rotating No. 3 Morse taper Omnimil vertical head

Standard 181 horizontal miller used for the Omnimil 00 conversion. On earlier models the electrical controls were on the left-hand side of the column with just a push-button starter on the front panel.

View from the left-hand side of an Omnimil 00. The lever protruding from the side of the machine at the rear was used to lift the motor to enable the V belt to be eased from one speed to another.

Early-model Juniormil with the switchgear mounted on the left-hand column face and the pick-off gears for the power table feed neatly if inconveniently stored in a compartment formed inside the rear cover.

With three motors to control - horizontal drive, vertical head and table feed - the need to group them together was solved on the early (Juniormil) model by mounting them neatly (but away from the operator's normal working position)  on the left-hand face of the column.

The 181 horizontal miller was also available with a mechanically-driven table when it became known as the "Juniormil" and formed the basis for the "Junior Omnimil".

Junior "Turret" miller. The "Juniormil" could be supplied without its horizontal drive components to become a purely vertical turret mill.

Left: looking almost identical to the  "00" Omnimil the "Junior" Model had a table power feed by means of a belt-drive take off from the top pulley through a telescopic shaft to a feed box built into the saddle; the drive could be engaged and disengaged by lifting or lowering a "dropworm" (see picture below) that connected the drive to the table leadscrew.

By using the swing facility of the head even long jobs could sometimes be machined on one setting

Just visible in the picture of a partially rotated Omnimil head is the intermediated drive pulley

Junior Omnimil 

Table-feed details for the Junior Omnimil

A useful "double-swivel" vertical head, with 360 rotation in each plane, was available to mount against  the horizontal spindle of the Model 181 horizontal miller.

The No. 2 Morse taper slotting head was driven by the horizontal spindle and had a stroke rate that varied from (a recommended) 100 to 150 per minute

Hydraulic copying unit in place on the Omnimil 00. The equipment included both a tracer and quill-feed unit, a mechanism to automatically reverse the table feed and a device to apply automatic increments of table cross feed at rates that varied from 0.004" to 0.060". The stylus pressure was 6 ounces, the maximum travel of the servo ram 2.5" and the response 13" per minute for 0.001" of stylus deflection.

Smallest of the Elliott dividing heads, the one for the
Omnimil and 181 had a centre height of four inches.

Table and T-slot dimensions

Floor Plan

Omnimil 00 Page 2   Elliott Millers Home Page   

A Manual is available for the Omnimil 00

Elliott Omnimil 00
Junior Omnimil & 181 Horizontal
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