email: tony@lathes.co.uk
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Meddings & Modig UBM-AM & UBM-30 Vertical Millers
A Manual is available for this miller

Modig UM3508 Miller   Meddings Drills



Made in Sweden, probably by the company responsible for the Modig lathes and milling machines, the UBM-AM Vertical Mill-Drill was marketed in the British Isles by the Meddings company  - who are better known for their various types of metal-cutting saws and drills, rather than conventional machine tools.
An improved and modernised version of the original Modig UM3508, the machine was supplied on a cast-iron cabinet, with a strong (550 mm x 1015 mm) supporting flange around its base. With the appearance and layout of a mini jig borer - like the similar multi-purpose American Vernon/Sheldon - the table was non-elevating but the head arranged to travel up and down on a wide and heavily rectangular-form braced pillar. The spindle was of high-tensile steel, with an ISO 30 taper, and ran in high-precision adjustable roller bearings; it was not bored through for a draw bar, instead (as on the Arborga) chucks and spindle fittings were retained by slotted washers and a nut on the nose. This is all well and good if the machine is carefully used and well maintained; however, any failure or damage in the nose area invariably means a new spindle and associated fittings will be required; offered one of these machines second-hand, it would be a foolish man who did not take a very careful look at these parts to ensure that the locking mechanism is complete, in good condition and functioning correctly. Autolock chucks and other nose fittings used on the UBM-AM also have to be of a special type - with flats to allow the hardened steel washers to slip on and act as pads against which the spindle nut can exert pressure. Modifying standard fitting to take the washers is, however, relatively straightforward given the use of a surface or even toolpost grinder..
Another disadvantage of the head type used on the UBM is the built-in motor; "built-in" anything is a usually a corollary for "added expense" and, in this case, if the motor fails, you cannot simply make up an adaptor bracket and replace it with one you happen to have on the shelf, it will need rewinding - at great cost.
Able to be swivelled 45 degrees either side of vertical the head could be moved though a range of 544 mm, the closest that the spindle nose could come to the table was 55 mm and the furthest away a useful 600 mm - the distance from the spindle centre to the rear pillar (throat) was 275 mm. Although very useful, a 45 degrees swivel is not nearly as convenient as many other machines - whose heads will go over 90 degrees. Equipped with both worm-and-wheel driven fine-down feed and a quick-action drilling by rack-and-pinion drive, the quill had 170 mm of travel and two rates of pre-set, automatically-disengaged power down-feed at 0.1 and 0.2 mm per rev. - the feed being engaged by an electromagnetic clutch operated by a push button.
Drive to the spindle came from a 2-speed, three-phase motor and a 4-speed gearbox to give a total of 8 speeds  from 170 to 2160 r.p.m., a range that be described as adequate.
Carrying three T-slots the table was 650 mm long and 270 mm wide with a generous 450 mm of longitudinal movement and 250 mm across. An optional table power-feed motor and gearbox was available with 6 rates of feed: 19, 36, 63, 96, 179 and 315 mm per minute.
A simplified version of the AM, the UBM-30 had a less powerful (but still two-speed) motor, a smaller 580 mm x 240 mm (22.8" x 9.4") table, 75 mm less head elevation, a No. 3 Morse taper spindle - and no power down feed..

UBM-AM Vertical Mill-Drill with power down feed head

UBM-AM with the head inclined

Above: an optional table power-feed motor and gearbox was available with 6 rates of feed: 19, 36, 63, 96, 179 and 315 mm per minute. Unless the unit was very light, the strain on the mounting flange looks to have been considerable ...

Section through the table-drive motor and gearbox. Two hardened hexagonal
clutches smoothed the drive with power transmission through splined shafts.



Motor for the optional power rise and fall to the vertical head.

The standard head elevation was by a handwheel driving through a bevel gear and screw thread.

Section through the spindle - the nose of which should be carefully checked for full functionality and lack of damage.

The UBM-30 was a simplified, less-expensive version of the AM machine, with a lower power (but still two-speed) motor, a smaller 580 mm x 240 mm (22.8" x 9.4") table, 75 mm less head elevation, a No. 3 Morse taper spindle - and no power down feed.



A Manual is available for this miller

Meddings Drills

Meddings & Modig UBM-AM &
UBM-30 Vertical Millers
email: tony@lathes.co.uk
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