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Porter-Cable (Mulliner-Enlund)
Toolroom Lathes

Porter-Cable Home Page   Porter-Cable Milling Attachment

Porter-Cable Carbo-Lathe

In reality a Mulliner-Enlund lathe (and looking very Hendey-like in its general appearance), the Porter-Cable "Toolroom" lathe was built in 12-inch and 14-inch swings. A machine dating from post 1910, for its era the lathe was entirely conventional and resembled, in all its parts, an ordinary American "engine" lathe - a type known in the UK as a BGSC (backgeared and screwcutting) centre lathe. Having bought out Mulliner-Enlund, Porter-Cable continued to use the original advertising literature and artwork; on some examples the Mulliner-Elund name was retained but the address changed to Syracuse, N.Y., while others were marked with three names as: Mulliner-Edlund Tool Compnay, Inc., Syracuse, N.Y. ; The Porter-Cable Machine Company, Successors and The Portland Machinery Co. Portland, Oregon. The lathe was listed as both a "Toolrooom" model (which might have been an advertising ploy, or may have reflected a genuine attempt to produce a lathe with better-than-average accuracy) and as the 12" and 14" Mulliner Quick Change Lathes. If there were any differences, at this distance in time, it's impossible to say.
When sold as a 12-inch model bed lengths of four, five and six-feet were available and as a 14-inch model five, six and eight-feet. The difference between the two versions was slight, and concentrated in the headstock the essential differences being: on the smaller model a backgear ratio of 10:1; a spindle bore of 15/16"; a 1.75" wide drive belt and cone diameters of headstock pulley 27/7", 41/2", 61/8", 73/4". The larger lathe had a 8.5 : 1 ratio backgear; a spindle bore of 1"; a 2" wide drive belt and cone pulley diameters of 35/8", 51/4", 67/8" and 81/2". Modest differences in the diameter and length of the spindle bearings were also present, with the 12-inch lathe having a tapered front bearing 3 " long that grew from 1 7/8" to 23/8" in diameter and a rear bearing 2 7/8" long 113/16" in diameter at its smaller end and 23/16" at the larger. The front bearing on the 14-inch was 5/8" longer and wider at the front by 1/8" and at the back by "; the rear bearing was " longer, wider at the front by 1/8" and at the back by 3/16".
With V and flat ways the deep-section, gapless bed was of the usual American pattern and arranged so that the ways ran on past the front and rear faces of the headstock. With the cross slide positioned exactly on the saddle's centre line, this allowed the toolpost to be brought right up to the spindle nose
With the casting running up to the centre-line of the bearings, the headstock incorporated one of the more important improvements incorporated in lathe design during the early years of the 20th century. It was fitted with a 0.50 carbon steel, ground-finish spindle tapered at the front and parallel at the rear running in
special analysis bronze bearings that could be pulled into their tapered seats by ring nuts to set the running clearance. Thrust was taken by hardened washers with lubrication provided by ring oilers that dipped into wells of lubricant below each bearing.
Drive to the traditional Hendey-Norton type screwcutting and feeds gearbox was through a conventional (though externally mounted) tumble-reverse mechanism with the gears inside the box having a pressure angle of 20. The output shaft was divorced from both power-shaft and leadscrew and connected to each by a sliding gear and multi-tooth dog clutch that allowed only one to be engaged at a time. The box, able to generate thirty-six pitches from 1 " to 400 t.p.i., was controlled by two levers, the usual sort of sliding spring-indexed plunger selector that moved across the face of the box and a three-position selector lever to the left. The boxes on both lathes were identical, only the difference in centre height calling for two of the changewheels to be altered.
With power sliding and surfacing speeds provided by a separate power shaft, the leadscrew was used only for screwcutting, saving wear on the unit and its large, well-supported clasp nuts. At the tailstock end of the bed the leadscrew hanger bearing was dowelled and bolted to the bed and the screw end fitted with adjustable thrust collars - the headstock end being free to float and so absorb small changes in length due to expansion during the working day.
Fitted with a keyway, the power shaft passed through the single-sided, open apron where it passed though and drove, via a key, a sleeve that was equipped, at each end, with a bevel gear. The sleeve was arranged to move sideways, under the control of a 3-position quadrant lever mounted on the apron's front face that, in its middle position centralised the sleeve and, when lifted or lowered into its other positions, caused one or other of the sleeve bevel gears to mesh with the left or right-hand side of a large bevel gear carried centrally on the inside face of the apron. The large bevel gear was connect to a train of gears that directed the drive to produce either a sliding or surfacing feed - the movement of the lever having the secondary function of engaging the appropriate gear train. Once selected, the feeds were engaged by a knurled-edge handwheel that, when turned, drew in a clutch (presumably a cone-type) to transmit the drive.
Using a powerful eccentric bed clamp, the set-over tailstock had 1.650" diameter spindle with a No. 2 Morse taper locked by a proper split-barrel fitted with a usefully long handle.
Well-made, the standard countershaft was built with an integral clutch, it's toggles almost certainly operated by wires connected to foot pedals. The central drive pulleys (inside one was the clutch) were 12 inches in diameter and 4.5 inches wide. On the 12-inch lathe the countershaft was intended to run at between 106 to 135 r.p.m. and on the 14-inch (with a set of smaller-diameter cone pulleys) at 160 to 210 r.p.m..

Porter-Cable/Mulliner-Enlund "Toolroom" lathe as manufactured circa 1910-1925

The same Porter-Cable 12" and 14" lathe as it was when branded as a "Mulliner"

Porter-Cable and Mulliner-Enlund lathe with Relieving Attachment. A popular option on lathe spanning the late 19th and early 20th centuries, it was designed to do under power what had previously often been done by hand - to accurately relieve (or back off) the teeth of taps, cutters, hobs and milling cutters - items that were often made in the factory in which they were to be used.

With the casting running up to the centre-line of the bearings, the headstock incorporated one of the more important improvements incorporated in lathe design during the early years of the 20th century

Fitted with a 0.50 ground-finish carbon-steel spindle tapered at the front and parallel at the rear, the headstock held special analysis bronze bearings that could be pulled into their tapered seats by ring nuts to set the running clearance. Thrust was taken by hardened washers with lubrication provided by ring oilers that dipped into wells of lubricant below each bearing.

Changewheel drive to the Norton-Hendey type screwcutting gearbox

Inside the screwcutting and feeds gearbox

A very distinctive thread-dial indicator

Fitted with a keyway, the power shaft passed through the single-sided, open apron where it passed though and drove, via a key, a sleeve that was equipped, at each end, with a bevel gear. The sleeve was arranged to move sideways, under the control of a 3-position quadrant lever mounted on the apron's front face that, in its middle position centralised the sleeve and, when lifted or lowered into its other positions, caused one or other of the sleeve bevel gears to mesh with the left or right-hand side of a large bevel gear carried centrally on the inside face of the apron. The large bevel gear was connect to a train of gears that directed the drive to produce either a sliding or surfacing feed - the movement of the lever having the secondary function of engaging the appropriate gear train. Once selected, the feeds were engaged by a knurled-edge handwheel that, when turned, drew in a clutch to transmit the drive.

The gearbox output shaft was divorced from both power-shaft and leadscrew and connected to each by a sliding gear and multi-tooth dog clutch that allowed only one to be engaged at a time.

At the tailstock end of the bed the leadscrew hanger bearing was dowelled and bolted to the bed and the screw end fitted with adjustable thrust collars, the headstock end being free to float and so absorb small changes in length due to expansion during the working day.

The set-over tailstock had a powerful eccentric clamp with the 1.650" diameter spindle taking a No. 2 Morse taper. The spindle was locked by a proper split-barrel with a usefully long handle.

Taper-turning unit: this could work over a length of 10.75 inches with a maximum taper of
4 inches per foot. The set-over was adjusted by a screw, a useful facility often omitted by other makers

Well-made countershaft with integral, toggle-operated clutch. The central wheels were 12 inches in diameter and 4.5 inches wide. On the 12-inch lathe the countershaft was intended to run at between 106 to 135 r.p.m. and on the 14-inch (with a set of smaller-diameter cone pulleys) at 160 to 210 r.p.m.

A superbly maintained, 6-foot long bed, Mulliner Enlund 14-inch engine lathe. The cleverly retrofitted overhead drive came from a 1930s South Bend 15" lathe - with its mounting probably necessitating the removal of the lathe's relieving attachment

Porter-Cable Home Page   Porter-Cable Milling Attachment

Porter-Cable Carbo-Lathe

Porter-Cable (Mulliner-Enlund)
Toolroom Lathes

email: tony@lathes.co.uk
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