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Weiler Primus Lathe

Weiler Home Page  Condor   Weiler Primus   Praktikant   Praktikus

Weiler LZ330   Commodor   Ergodor   Matador   220, 250, and 280 Series

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RDT-260, LZT-280N, LDT-250/6 & Variants

A manual is available for the Primus Lathe and for other Weiler Lathes

If you have a Weiler Primus, the writer would be interested to hear from you

Intended for use in light engineering and repair  workshops, experimental departments and training establishments, the Weiler Primus was constructed to the Company's usual high standards of fit and finish. With a centre height of 120 mm (5.3") and accepting 450 mm (17.7") between centres. it was normally supplied on a braced, sheet-metal cabinet stand, with a built-in chip tray - but could also be configured for mounting on the customer's own bench. It was available in two versions, the LZ and LD, the former having a screwcutting and feeds gearbox and power cross feed, the latter screwcutting by changewheels and hand-operated cross feed.
Built using a high-grade iron casting, the 155 mm (6.1") wide bed featured deep, strong walls at front and back cross-braced by tunnel ribbing; the flat ways were not formed from the bed material but separate strips of hardened steel (HRC 60-62) screwed in place. Continuing a tradition through to have begun in England during the 1800s, the carriage was guided by narrow vertical faces at the front and between the horizontal surfaces - just like a Series 7 Myford - with swarf and dirt was kept at bay by the use of Polyamide wipers.
Running in high-precision, adjustable taper-roller bearings with labyrinth oil seals giving sealed-for-life lubrication, the 40 mm (1.57") bore headstock spindle was equipped with a DIN 55021-4 taper and a No. 4 Morse socket - complete with a hardened sleeve designed to accept direct-fitting, draw-tube retained W23 collets with a maximum pass-through bore of 16 mm (0.63").
Rather unusually, each version could be had with a choice of drive system: a fully geared headstock, or by V-belt from a countershaft unit. The former used, as standard, a 2-speed, 1.2/1.5 kW 1500/300 r.p.m motor mounted on the underside of the headstock with twin V-belts taking the drive to the input pulley and speed changes made by the juxtaposition of two levers on top of the headstock. As described, the arrangement gave a useful total of 18 speeds spanning a wide 60 to 3000 r.p.m. - though there was also the option of a 750/3000 r.p.m. 2-speed motor that gave an improved range from 30 to 3000 r.p.m. When fitted with the all-V-belt drive countershaft, just a single motor could be specified, the same 2-speed, 1.2/1.5 kW 1500/300 r.p.m. unit offered as an option on the geared-head machine, the installation giving 16 speeds from 150 to 3200 r.p.m. (though the slowest speed was really too fast for screwcutting by other than more experienced operators). The countershaft-equipped lathe was fitted with a unit of a simple but robust design, the motor being mounted on the underside of a steel plate bolted to the back of the headstock. A 4-step pulley on the motor took the drive upwards to a matching intermediate pulley held on one end of a spindle running in bearings mounted in an eccentric housing - the arrangement allowing the belt tension to be adjusted (as genuine, matched sets of V-belt pairs now appear to be unavailable - and a pair of unmatched, ordinary belts can cause noise and vibration) - today the solution is to use a belt of the accurately made T-Link type).
On the other end of the shaft, a 2-step pulley took the drive to a matching pulley overhung on the end of the headstock spindle. Fitted with this system, sixteen speeds were available from 150 to 3000 r.p.m., again the slowest being uncomfortably high both for screwcutting and the turning of large-diameter workpieces.
Oddly, for a modern machine that must have complied with the latest safety regulations, all electrical controls were mounted on the front face of the stand's right-hand plinth. Should the operator's have been involved in an industrial-quality accident, not having immediate and easy access to the emergency stop button would  have seriously impaired his or her chances of avoiding injury.

Continued below:


Continued:
On the LZ version, screwcutting and power sliding and surfacing feeds were provided by (in comparison to other lathes in the maker's range) a simplified oil-bath lubricated gearbox with the most highly stressed gears hardened, all shafts running in ball or roller races and control by just two rotary knobs. Without altering the changewheel set, a limited range of just fifteen screwcutting pitches from 0.25 to 5 mm were available with the same number of power sliding feeds that ranged from 0.03 to 0.3 mm (0.0018" to 0.01881") per revolution of the spindle using the standard changewheel set (with power cross feed at half those rates). However, extra gears were available that, when fitted, gave a better range from 0.02 to 1.0 mm. With the necessary transposing changewheels fitted, inch pitches from 5 to 96 t.p.i. and Mod from 0.25 to 4 MOD could also be generated.
Although relatively short in terms of its saddle length, the carriage assembly was, nevertheless, beautifully constructed, Doubled-walled, the apron used shafts supported at both ends in anti-friction bearings; oddly, unlike the contemporary but larger and more expensive Praktikus L (which used a slotted leadscrew to provide both the screwcutting and power-feed drives) the Primus had a separate powershaft. Both leadscrew and powershaft ran, at both ends, in anti-fiction bearings with drive from the exposed leadscrew picked up by the usual type of double clasp nuts. Sliding and surfacing feeds were selected by a push-pull knob - with the middle neutral position engineered to allow engagement of the leadscrew clasp nuts. Feeds were engaged by lever through a form of clutch first introduced pre-WW2 on American lathes, the mechanism incorporating what Weiler described as a "ball sliding clutch" to protect the drive. Fitted with a large micrometer dial, the carriage handwheel gave a travel of 15 mm (0.6") per revolution.
Full length - and so better able to even out wear over its ways that a short type - the cross slide had a generous 150 mm (5.9") of travel and was topped by a 80 mm (3.1") travel tool slide able to be swivelled through 180. Both slides were fitted gib-strip adjustment screws on very close spacing and driven by hardened, trapezoidal-form feed-screws running through wear resistant "PAN-bronze" nuts. The zeroing micrometer dials were of a decent size, dull-chrome plated and crisply engraved at intervals of 0.02 mm. Between the top surface of the tool slide and spindle line was a gap of 22 mm (0.87") that allowed tools up to 14 mm (0.55") deep to be held in the maker's quick-set toolpost. One (expensive) option for the carriage assembly was an infinitely-variable speed drive - this being provided by a motor flange mounted against the face of a step-down gearbox at the tailstock end of the bed.
Fitted with a captive handle and an eccentric bed lock, the set-over tailstock held a hardened and ground No.
2 Morse taper, 30 mm (1.2") diameter spindle with 80 mm (3.1") of travel and graduated with ruler lines on a 1 mm spacing. Running in a close-fit, honed bore, the spindle was locked by a proper split-compression bush and fitted with a zeroing micrometer dial.
Supplied with each new Primus was a complete set of electrical equipment - enabling the lathe to be run immediately upon delivery - Morse centres for headstock and tailstock, a headstock spindle reduction sleeve formed to take direct-fitting collets, a collet draw-tube, carriage stop, a set of seven screwcutting changewheels for the LD model, a pressure grease gun, spanners, five shear pins for the leadscrew drive and an operation manual.
In an obvious attempt to compete with the Austrian-built Emco V10 and V11 lathes, one interesting accessory was a powered vertical milling/drilling head that bolted to the back of the bed. Closely resembling the Emco unit - but of higher quality with both the No. 2 Morse taper, 50 mm travel quill and main column hardened - that on the Weiler had a maximum distance between spindle nose and table of 350 mm and a throat of 210 mm. Further high-class engineering was to be found in the drive system, a flange-mounted, 0.37 kW 3-phase motor driving through oil-bath lubricated, planetary gearing that gave stepless speeds in two ranges: 85 to 540 r.p.m. and 335 to 2200 r.p.m..   

Weiler Primus Model LZ with screwcutting gearbox and power cross feed


Primus LZ with the optional variable-speed, electrically driven carriage

Front of the screwcutting and feeds gearbox removed showing the essentially simple construction that gave only a limited number of pitches and rates of feed

Primus with the V-belt drive countershaft that gave almost silent running

Geared headstock version of the Primus

In an obvious attempt to compete with the Austrian-built Emco V10 and V11 lathes, one interesting option was a powered vertical milling/drilling head that bolted to the back of the bed. Closely resembling the Emco unit - but of higher quality with both the No. 2 Morse taper, 50 mm travel quill and main column hardened - that on the Weiler had a maximum distance between spindle nose and table of 350 mm and a throat of 210 mm. Further high-class engineering was to be found in the drive system, a flange-mounted, 0.37 kW 3-phase motor driving through oil-bath lubricated, planetary gearing hat gave stepless speeds in two ranges: 85 to 540 r.p.m. and 335 to 2200 r.p.m.




A manual is available for the Primus Lathe and for other Weiler Lathes

Weiler Home Page  Condor   Weiler Primus   Praktikant   Praktikus 

Weiler LZ330   Commodor   Ergodor   Matador   220, 250, and 280 Series

Weiler LZ280 & LZ300

Weiler LD-220, MD-220, LD-250, LDS-250, LDT-250, MF-220,

RDT-260, LZT-280N, LDT-250/6 & Variants

Weiler Primus Lathe
E-MAIL   Tony@lathes.co.uk
Home   Machine Tool Archive   Machine-tools Sales & Wants
Manuals  Catalogues   Belts   Books   Accessories



If you have a Weiler Primus, the writer would be interested to hear from you