1974, after 37 years of production, the 6" Atlas (now catalogued as
the Model 3950) had been extensively redesigned and, in an effort to
keep the price competitive was being sold direct from the factory.
Two versions were available, one Imperial (English) and the other
metric; the latter machine, known officially as the Atlas 150, was
able to cut only metric threads - of which 23 were available from
0.1 mm to 3.0 mm. The leadscrew, cross feed and top slide screws
were also of metric pitch and the feed dials, tailstock barrel,
threading chart were all in metric calibrations - in other words, a
complete metric machine rather than just a simple screwcutting
conversion. The version with English calibrations offered
threads between 8 and 96 tpi (or optionally, at extra cost, from 5
tpi) using, in addition to ordinary changewheels, a novel and
ingenious system of "Gearsettes" - combinations of changewheels
(sold in 6 different sets) marked with a circular metal disc that
indicated the thread and feed range - together with an indication of
which other gearwheels would mesh with them to provide the correct
set up. As a comparison the Myford ML7 will only cut down to 8 tpi
with the changewheel cover closed - if coarser threads are required
the cover has to be left off and gears larger than 75t used on the
A major change involved removing the expensive
countershaft assembly, bolting the motor directly to the bench
behind the lathe and fitting the headstock drive pulley in an
overhung position on the left-hand end of the 17/32" bore, 1" x 10
tpi, headstock spindle. To tension the belt, in the absence of
any means of moving the motor, a simple adjustable jockey
on a stud, was fitted above the belt run. Unfortunately this
"modern" method of engineering a headstock drive had the effect of
reducing the number of spindle speeds from 16 to 8 but with a
still-respectable range of 55 to 2300 rpm with the maker's
recommended 1/3 hp 1725 rpm 60 cycle motor. The Emco Compact 8,
Myford 254 and various modern Chinese lathes also use a similar
drive system - but were not the first small lathe makers to employ
this cost-saving set up, the EXE Company of Exeter, England, used
exactly the same idea on their machines in the 1930s, as did several
makers of cheaper, less highly-stressed wood-turning lathes. The
carriage showed evidence of cost cutting as well, though in this
case the results were not so benign; the cross slide was still of
the "short" type - which wore just the central portion of its ways -
and an adjustable gib strip was fitted at the back of the saddle.
This had become an old-fashioned method of adjusting the saddle to
the bed in the 1920s and, although more complicated to engineer, the
strip should have been placed at the front, so leaving a "solid"
rear face to take tool thrust directly against the bed. Although,
with its chrome-plated handles, the compound slide
rest looked very handsome, lurking beneath the surface was a
drawback: the gib strips were made of plastic and the
metal-reinforced dimples for the adjuster screws tended to snap.
This did not affect the side-to-side play by allowed the slide to
lift when a heavy cut is made; making, or having made, a new set of
metal gibs is the obvious, low-cost solution.
could be adjusted to set over for taper turning, was solidly built
and, happily, used a proper compression fitting to lock the 3/4"
diameter spindle. The travel however was only 1.25 inches and the
Morse taper a No. 1 - these (together with the very short cross
slide) being the only serious specification failures in an otherwise
well-designed little lathe sold at a price affordable by the amateur
In 1974 the lathe was painted grey but at some unknown
point, before production ceased in 1980, this was changed to
Mechanically the early and late versions of the Mk. 2 Atlas
6-inch are identical, however, early versions appear to have been
fitted with Japanese-manufactured NTN ball bearings in the headstock
whilst later models used Timken tapered-roller bearings. The lathe
was 34" long, 17" deep and stood 11 inches high; it weighed
approximately 92 lbs without its (extra-cost) electric motor.
Additional Atlas 6-inch Mk. 2 pictures can be found here..