ML7 - General Specification:
Of ribbed box-section, the bed was constructed with a flat top of typically English design, with narrow vertical shears, the nearer vertical element of the gap between the front and back ways being shared by the saddle and tailstock. This is not an ideal situation but, in practice, causes no problems until the bed wears badly when, as the tailstock is brought close to the headstock, it's central locating tennon becomes loose. One advantage of the bed design is the relative ease of regrinding with all the main surfaces at either the same level or at a right-angle to each other.  The back face of the bed is machined flat and equipped with tapped holes ready to accept a taper-turning attachment. The design of the saddle is interesting, with shimmed plates at front and rear by which means a very close vertical fit can be obtained; at the front, instead of a full length inner lip, just a short one is employed, no wider than the cross slide, and it is on this surface that tool thrust is taken. A consequence of this design quirk is that the four gib-strip adjustment screws along the front edge of the saddle take some skill to set correctly with only two bearing against a firm surface; to get the setting correct the maker's instructions have to be followed to the letter. Towards the end of ML7 production a New Zealand engineer pointed out that it would be better if the tool thrust was to taken along the full length of the saddle's inner rear face and against the bed's fourth vertical shear counting from the front. By this means an otherwise unused already-machined surface could be used and (combined with an adjustable gib strip) a much longer and more stable contact obtained. Unfortunately the New Zealander's proposed method, whilst possible in an experimental situation, was not suited for production and so Myford - probably following the appearance of an article in Model Engineer Magazine proposing a similar but rather more straightforward modification - came up with a system (from K107657) that involved machining away the original short contact at the front and using a modified casting to keep the relative position of apron and leadscrew the same. The saddle to bed contact was arranged against the rear shear but the gib strip adjustment kept at the front.
Pressure die-cast in a form of ZAMAK (it looks like aluminium) the apron is fastened to the saddle with 3 cap-head screws and with the leadscrew clasp nuts guided in adjustable, gibbed ways. On early machines the reduction gearing between carriage traverse handwheel and rack was exposed (and quickly collect swarf and dirt) but this fault was soon corrected and a close-fitting cover provided.
Whilst the Super 7 was fitted from the start of production with a long slide as standard that on the ML7 was always shorter (with 5-inches of travel and four 3/8" T-slots) but with the option, at extra cost, of a longer 10.75-inch slide (and matching longer feed screw) with five T-slots. Even so, the standard slide has a generous 30 square inches of clamping surface and, with the top slide removed, is ready to be used as miniature boring table or to mount a milling slide or rear toolpost. Until Machine K108718, slotted BA screws and locknuts were used for the gib-strip adjustment but after that were replaced by easier-to-set self-locking 5mm pitch hexagon-socket screws .
Able to be swivelled 63-degrees either side of zero the 2.5-inch travel top slide was fitted with the same 10 t.p.i. Acme-form feed screws as the cross slide and both carried identical micrometer dials die-cast in ZAMAK; these, whilst a "character" part of the machine, are not as easy to read as the properly-engraved units fitted to very late models. The toolpost clamp post is surrounded by three little tapped holes, intended to accept the mounting screws for the indexing plate used on the 4-way toolpost; as supplied from the factory each hole was sealed with a small grub screw to prevent swarf working its way through to the feed screw and wearing it out.
In comparison with almost every other contemporary small (British) lathe the headstock of the ML7 is a rugged affair and bolted to the bed by 4 high-tensile cap-head Allen screws and aligned by a ground rectangular locating tongue fitted into the gap between the bed ways. Two pusher screws, entering from the rear, press against the tongue and so hold the headstock hard against the inner vertical bed way. The spindle is in 40-50 tons high-tensile steel and runs in plain, parallel Glacier TI Alloy "half-step" bearings with laminated (0.002") shims between the upper and lower bearing halves to allow a degree of adjustment. Strong bearing caps are used, each bolted down by two socked-headed cap screws, and a ball-thrust bearing fitted in a shielded position at the left-hand end. The spindle is offset from the bed centre line towards its rear - a feature the makers ingeniously claimed in their first publicity sheet: "The distinct advantage of the offset is paramount when turning large diameters, the degree of rigidity being equal to that of a bed 5-inches wide with the headstock centrally disposed." The spindle on early machines was fitted with a pair of simple little No. 2 size wick oilers (easily neglected) whilst later models have proper drip-feed lubricators where the supply of oil can be adjusted (according to the spindle speed) and the quantity remaining easily inspected. The dimensions of the original spindle - 1.125" diameter, bored through 19/32", No. 2 Morse taper, front bearing section 1.25" diameter, rear bearing section 1", bull gear section 1.125", 12 threads per inch nose backed by a plain register 1.25" in diameter and 0.4375" long. - were carried over to the Super 7 and only changed with the advent of the new-for-2001 Super 7 Plus. The drive from countershaft to spindle is by 3-step aluminium pulleys with a proper, full-sized A-section V belt that allows full use to be made of the motor's power (generally 0.33 h.p. on early lathes and 0.5 h.p. on later) whilst the robust backgear assembly (clustered at the front under the spindle line) means that speeds down to around 25 rpm can be achieved with greatly increased torque - and no risk of belt slippage - ideal for both screwcutting and turning large blocks of metal held in a four jaw chuck or on a faceplate. On both ML7 and Super 7 that part of the (bronze) backgear carried on the headstock spindle is in the form of a "sleeve pinion" - that is, the small gear is extended to form a long bush on which the pulley is pressed, the whole assembly rotating on the spindle when backgear is engaged - a design that does much to enhance the lathe's ability to run reliably at slow speeds for long periods. Unfortunately the assembly does contain a weak point: the 3-step aluminium pulley is only pressed onto the sleeve - and it is not unknown for it to become loose and rotate. However, if the assembly is stripped, cleaned and the pulley secured onto the sleeve with a slight smear of low-strength Loctite all will be well.
For quiet running the makers recommend a resilient-mounted motor (with rubber rings isolating the main housing from the foot) and, so equipped, an ML7 will run almost silently. Whilst all Super 7s have a clutch fitted as standard, on the ML7 this was an optional extra - but one well worth having. The ML7 unit economised by utilising the brake shoes from the front wheel of a Nottingham-made Raleigh moped, the "Gadabout".
In place of the crude assembly used in pre-war years, with plain-bore changewheels running directly on studs and retained by split-pins and washers, the changewheel drive on the ML7 is properly engineered. Hardened steel pins are employed carrying bushes keyed into the gears and with neat, quick-release washers retained by slot-head screws allowing the gears to be changed quickly. Unfortunately the nuts holding the pins were still behind the banjo, making any alteration in position a fiddly, time-consuming business. The changewheels, like the belts, are enclosed inside a neat, thin-walled cast-aluminium cover. Tumble reverse is fitted as standard, allowing quick reversal of the saddle drive - and so speeding up the boring of deep holes, etc. Setting the tumble-reverse lever to "neutral" means that high speeds can be used without having to drive the changewheel set and this makes an already very-quiet lathe even more acceptable in a domestic situation - many being used in attics and even spare bedrooms. The 8 t.p.i. left-hand thread leadscrew is of Acme form, 5/8-inch diameter and runs in Oilite bushes. On the original ML7 both the tumble-reverse and backgear levers were tipped with lovely little acorn-shaped plastic knobs - in what must have been a subtle reference to Nottinghamshire's woodland heritage.
Able to be off-set on its sole plate for taper turning the tailstock was fitted with a 1-inch diameter barrel, threaded 8 t.p.i. and with a No. 2 Morse taper - so allowing heavy-duty drilling. The barrel is bored clear and passes through the handwheel - an arrangement that does have some advantages, notably if used for long-hole boring when woodturning. 
Although the ML7 changed very little during its production life some improvements were made: by 1950 the countershaft had been given more substantial uprights and the back made solid instead of having three open panels: the original ball-spring "Bennet" oilers were replaced by proper nipples to which a pressure oil gun could be applied to blast out dirt and drive oil to where it would do some good (note: all nipples, on all models of Myford, took oil, never grease): by 1960 the tailstock casting was filled in and its "off-set" guide moved to a thicker part of the casting: in 1969, from machine K90494, a cast lug was added to the headstock to provide a location point for the lever-action collet closer - this had previously been supported by a bronze bracket, clamped by two Allen screws to one of the cast-in strengthening ribs behind and immediately below the front headstock bearing: during 1973, from machine K111727, production was rationalised around just one 7-series bed, that for the newly-introduced, power cross feed Super 7 - the change of bed also forced the use of the superior cast-iron apron and 3/4" diameter leadscrew from the Super 7 - improvements which mean that these late ML7s  have the very best specification of all. The last ML7 (K140848) left the assembly line on the 31st of January 1979.
ML7: Speed Range:
As supplied to the UK market (with a 50 Hz 1425 r.p.m motor) the ML7 has a speed range of: 35, 62 and 110 in the 5.78 : 1 ratio backgear and 200, 357 and 640 rpm in open drive. Although it is perfectly possible to raise the top speed by increasing the size of the pulley on its motor, it is wise to bear in mind that the maximum recommended speed of the original white-metal bearing model is 1000 r.p.m. I have known machines to be run at much higher speeds, without apparent ill effect, but these were in good condition, carefully set up and with an increased flow of top-quality lubricant from their oilers; a worn machine treated like this might not take at all kindly to the treatment.
At one time, in order to permit higher speeds to be reached with reliability, the option of a kit containing bronze headstock bearings and a hardened spindle was available at extra cost  - and these parts are now supplied as standard when replacements are required. Because the oil feed to the bearings is "constant loss" it is important to make sure that both oilers are topped up and opened to give a generous rate of feed - one drop per 30 seconds as a minimum - every time the machine is run. I have seen countless ML7 lathes that, despite having given more than fifty years of service, still have bearings that are "spot on". Of course, the oil has to go somewhere and runs down the front and rear faces of the headstock to end up in the ship tray.
ML7: Electric Motors:
One of the most frequent problems with any small lathe is the 1-phase motor. These are best run near their rated capacity all the time (i.e. worked nearly flat out); if the motor is switched on and off frequently against "no load" the windings will be damaged and, if run through a cycle where it is started, worked briefly, stopped and started again, the capacitor will fail prematurely.
It is very important not to "over-motor" a Myford (or indeed any other lathe); any accident or dig in will have far more serious consequences - and if the machine is worked beyond its capacity excessive wear will occur. Early ML7s were fitted with 1/3 hp motors and later ones with 1/2 hp - a figure that should not be exceeded. The Super 7 has always been fitted with a 0.75 hp motor (necessary to pull the top speed of over 2000 rpm) and this too should be respected as an absolute maximum. The original Brook-Crompton motors are very expensive; however, direct replacements, of exactly the same specification but more economically priced, are now available.
Buying a Used ML7 - and value for money:
When contemplating a used Series 7 Myford its age is irrelevant (unless you require a particular specification); mechanical condition is everything and I have seen many machines over 55-years old that have either had so little use, or been so carefully taken care of, that they appear to be only a year or two old. Whilst late machines have their serial numbers stamped into the front of the bed, just to the right of the gap, earlier versions had theirs in a difficult-to-find location punched into the vertical way on the rear of the bed at its tailstock end. If you can find a good-condition ML7, especially one with the original bed machining marks intact and wearing its maker's paint, it will represent tremendous value for money. In addition, even if the machine shows signs of careless use, every mechanical spare is available direct from the factory to restore it to "as-new" condition. With the removal from the spares-counter of the teenage girl, it's even possible to talk to somebody who knows the lathe intimately. Don't be tempted to make or modify parts yourself - use original components and preserve the authentic look and feel of the machine - this will not only enhance its value, but also make using it a much more secure and enjoyable activity.
It is much more difficult to find a good Super 7; competition for them is strong, which raises prices well above those of the ML7 - often twice as much, model for model; the ML7 really is the bargain version.
A selection of used Myfords can often be found for sale here
Continued below:

Continued:
Super 7: General Specification and comparison with the ML7
When it appeared in late 1952 it was immediately obvious that the Super 7, although built with the same bed-way dimensions as the ML7, was a thoroughly re-engineered design, with many significant improvements. Super 7s of all years are well finished, but post 1960 models appear to have enjoyed more careful filling of the castings and a better cosmetic paint finish--as well as the traditional fully-machined and chemically-blacked nuts and bolts.  Until 1959 the lathe had a distinctive drip-feed oiler built into the front of the headstock casting, the circular window of which was just to the left of the chuck, and the countershaft assembly ran on needle roller bearings with the (standard-fit) clutch contained within the countershaft's central 4-step cast-iron pulley. Surprisingly, the needle roller bearings gave rise to noise and vibrations - and the clutch was also prone to rattle unless correctly adjusted - reference to the maker's instructions on this point is vital. A point about needle-roller bearings - in case any owner is tempted to convert their later "Oilite" bushed countershaft: being comparatively flimsy items needle roller bearings should only be used in places where very high standard of machining can be guaranteed - that is, in perfectly round housings and on shafts that are hardened and ground - or adapted to use the hardened inner races that most needle roller bearings can be supplied with.
In June 1958, from lathe SK 8128, the clutch was moved to its current position inside the large countershaft pulley and the countershaft bearings changed to plain Oilite bushes. This significant re-engineering of the drive (which also involved new belt-guard covers) made a huge difference to the running of the lathe making it both smoother and quieter. In May 1959, from machine No. SK 9167, the expensive-to-produce drip-feed oiler was abandoned and a sump provided beneath the bearing with feed by a wick - a change that did at least have the advantage that it was no longer possible for foreign matter to find its way into the bearing. It is useful, though not official, to refer to these plain-bearing countershaft machines as the Super 7 Mk. 2.
The headstock drive system (powered by a 0.75 hp, 1425 r.p.m. motor and with a clutch fitted as standard) has 16 speeds; however, allowing for the fact that the two fastest backgear speeds in high range are not recommend for use this gives 14 speeds of: 27, 39, 54, 77, 95, 135, 210, 300, 420, 600, 740, 1050,1480 and 2105 rpm - an especially 'deep' range that goes a long way towards making the Super 7 such a versatile and adaptable machine. In the USA, with 60 Hz motors running at 1700 rpm, the speed range is correspondingly faster. The drive from the motor to the countershaft is arranged with 2-step pulleys (rather than the single of the ML7) - whilst the headstock spindle carries four speeds instead of three. Both countershaft pulleys, and the headstock cone pulley, are made in cast iron (a much better material for belt drive than aluminium) and the rotating masses of which assist a single-phase motor by providing a useful "flywheel" effect. For many years the rather fragile and easily distorted two-step motor pulley was in aluminium, but this was changed to cast iron (so matching its countershaft equivalent) at some point in the 1980s.
In place of the ML7's plain white-metal bearings the Super 7 spindle runs in a tapered bronze bush at the chuck end and a pair of angular-contact ball bearings at the rear. The ball-races are housed between screwed rings - which are used, by moving the spindle backwards and forwards, to provide a precision method of adjusting the front-bearing clearance. The spindle is immensely rigid and known for long, trouble-free life; the backgear assembly is similarly beefed-up, uses stronger gears and is fitted with a very handy "flick-over" quick-release" mechanism.
With a longer travel than the ML7 the Super 7 tailstock was also fitted with a ball-bearing thrust race, a quick-feed, multi-start thread, self-eject for the centres and a longer barrel and housing. On both lathes the tailstock is improved immeasurably by the use of the optional lever-operated attachment; the increased sensitivity when drilling, especially on very small diameters, is well worth the expense.
Longer - and with an extra T-slot - the Super 7 cross slide abandoned the loose "gib strip" and was fitted instead with a pair of rigid "gib blocks" screwed into the roof of the slide. The top slide is able to rotate through 360 degrees and employs a tapered spigot mounting instead of a clamp. The micrometer dials are engraved (not cast), have much larger (adjustable) thrust pads and can be "zeroed" - when correctly set-up the "feel" of a Super 7 slide can be almost equal to that of a Schaublin precision bench lathe.
Stronger, with larger, quieter-running fibre gears the tumble-reverse mechanism is considerably improved whilst the changewheels run on much improved, "quick-set" studs where, to adjust the relative position of a gearwheel, it is necessary only to slacken a nut on the outer end of each stud instead of having to release one hidden behind the banjo arm. The gear and belt-guard covers are much more convenient, being arranged to hinge open instead of having to be slid or removed.
0.75-inches in diameter, the leadscrew was matched with suitably larger and longer-lasting clasp nuts and the right-hand leadscrew bearing hanger more stiffly mounted by being doweled as well as bolted to the bed. Made from cast iron instead of "aluminium" the Super 7 apron is more robustly constructed and, from 1974 and machine SK 115830  power cross feed was available. Two minor changes occurred on this model shortly after production started with the substitution, in June 1975, of the original bronze cross slide feed by one made from hardened steel (from lathe SK 122657) and in December 1975, (from SK 126004), with the power cross-slide feedscrew modified resulting in a larger counter-bore in its micrometer dial. Even today any type of power-cross-feed Super 7 is relatively rare on the used market, especially one owner, carefully-used examples. It would seem that, once you have one of these machines, you simply don't want to part with it.
Colour seems to play an important part in people's perception of a machine's vintage so it is sobering to know that the first green Super 7 was produced as long ago as April 1977, from machine number SK 142981. Later in the same year, in November: from machine SK 136311 the power cross feed apron was partially redesigned with an adjustable cam provided to correctly set the engagement of the leadscrew clasp nuts.
Surprisingly, whilst many other makers have been content to allow their lathes to be re-branded for overseas markets, Myford were never tempted down this road - the only known exception being the application, in the USA, of badges proclaiming: "Allied AMMO 7" x 30" G " to some long-bed, screwcutting-gearbox equipped Super 7s of the 1960s. A least four "Chinese copies" of the Super 7 were manufactured and distributed as the "Whitecote", "Whitecolt 720" with another clone, presumably by other maker, being badged "Tiger Turn". One copy, the "Prakash", came from India but was branded "Atlas" on the headstock - using a badge similar in appearance to that on the American Atlas lathe (if you have a Prakash, please contact the writer). These imitation Myfords are easily recognised by their crude appearance and look quite at odds with the superb finish of the genuine article.
Myford Super 7 Plus
Introduced in 2001 the latest (Mk. 3) version of the Super 7 lathe has a spindle bore able to pass a 1-inch diameter bar, a M42.5 x 2mm pitch nose and a 4 Morse taper socket. The headstock and its bearings are arranged in exactly the same way as before, but with the spindle gears and backgears suitably enlarged and modified. The drive from the motor to countershaft is now by a Poly-V belt (with two-step pulleys as before) - a modification that has made a significant improvement to smooth running on top speed. The drive from the countershaft swing-head to the spindle remains as before - a standard V belt that can be expected to give years of reliable service. Both countershaft and changewheel guards have been increased in thickness in recent years and the rather weak spring-held closures (which could easily be knocked open by a light blow in the right direction) changed for neat, positive 1/4-turn locks operated by a square-socket spanner. To improve the feel of the cross feed a needle-roller thrust bearing has been incorporated in the end bracket.
Myford Super 7 Connoisseur
The newest Super 7 and one fitted with numerous extras as standard: inverter-controlled variable-speed drive from 26 to 3000 r.p.m. , spindle clutch, screwcutting gearbox, hardened bed, spindle indexing (by use of the backgear bullwheel), Poly-V drive to the headstock spindle and mounted on the new-type industrial stand. 
Gearboxes and Screwcutting:
In standard form both lathes use changewheels for screwcutting and can generate (with the standard changewheel set) pitches from 6 to 112 t.p.i. (or 0.25 to 4mm). However, both could be ordered (or retrofitted) with a screwcutting gearbox thus becoming, with the addition of a suffix to their model numbers, the ML7B and Super 7B. The gearbox generated 48 threads from 8 to 56 t.p.i. and the same number of feeds (by the simple expedition of pulling out a double gear mounted on the banjo) of  0.139" to 0.002" per revolution of the spindle.
Although in the late 1940s a kit-form gearbox had been designed and marketed by L.H.Sparey (author of The Amateur's Lathe) it was not until 1953 that Myford's first effort appeared. Lubricated by an oil-bath it was designed along long-established "Norton Quick-change" lines with a single-tumbler and a reversible gear on its left-hand face that allowed a change to be made between fine feeds and threads. Early boxes were fitted with unhardened gears and (hidden under a rounded, aluminium cover) a pair of external gears on the right-hand face (from which the leadscrew drive was taken) but in 1956, from box QC 2501, important alterations were made with a change to hardened gears and a leadscrew that was much better supported by being allowed to pass all the way through the box with the drive taken from its left-hand end - so allowing the external gears to be dispensed with. It is worth noting that the Metric Conversion Set for the early box is different - the four gears needed being: 2 x 60t, 1 x 44t and 1 x 52t. Later boxes require five gears: 2 x 60t, 1 x 50t, 1 x 45t and 1 x 63t. The standard Metric Conversion Set - with its fixed stud positions - was replaced during the 1990s by a slotted quadrant arm on which can be mounted ordinary changewheels and studs - and so enable the generation an almost unlimited number of English, Metric and odd threads and feeds. The Myford gearbox is a beautifully made and very tough unit and, with a supply of lubricant in its base (not something that every maker of small lathes considered important) very reliable. The only signs of wear one should encounter are in the shaft bushes; if the gears show signs of damage then the box must have been mishandled or denied lubrication, in normal use it is simply impossible to wear them out.
The standard set of gears supplied with a "changewheel" ML7 or Super 7 comprises: 2 x 20, 25, 30, 35, 38, 40, 45, 50, 55, 60, 65, 70 and 75t. To cut a wide range of metric threads requires, in addition, just two 21t wheels. Myford 7 and 10 Series changewheels of all years were of 20 D.P. and 20-degree pressure angle
Metric Models:
All 7 Series lathes were originally available in both metric and Imperial (inch) versions, but the latter is by far the most common on the second-hand market. Besides the screwcutting conversions already outlined, to convert the rest of the lathe requires only the changing of the cross and top-slide feed screws, nuts and micrometer dials with metric equivalents. Although the cross and top slide nuts and screws are, of course, proper metric units, no Myford was ever fitted with a metric-specification leadscrew - the generation of metric pitches always being achieved by using the appropriate changewheels in conjunction with the "inch" leadscrew. 
ML7 Tri-Leva:
Designed to fit the headstock of the ML7 (but not Super 7) the Tri-Levawas an attachment intended to perform both as a clutch and allow instant changes of spindle speed. The device was beautifully made and finished and consisted of a lower housing (bolted into place under the headstock spindle by three extended-thread headstock bolts) that acted as both a mounting shelf for the upper part of the unit and an alignment guide for the three permanently-mounted drive belts that formed the heart of the conversion. The upper part of the unit, fastened to the countershaft, held a similar belt guide and three spring-loaded rollers each of which could be pressed down to engage its own V belt. An interconnecting mechanism released the "engaged" selector when the handle of another was depressed. The Tri-Leva was expensive, especially when equipped with the optional two-speed motor and associated switches; in 1962, for example, it would have added 35% to the £70 : 15 : 0d cost of a Standard ML7. As a result, most units appear to have been fitted on lathes bought by professionals and intended for production work. More Tri-Leva details can be found here
Myford ML7R:
Introduced at more or less the same time as the power cross feed Super 7, this is the lathe that confuses people new to the make. Although called an ML7 - and you would therefore expect it to be a development of, or directly related to, the original machine of that name - it was actually a non-power cross feed Super 7, but without a clutch and fitted with ML7 cross and top slides. It was designed to replace the ML7 and allowed a rationalisation of production around just one model of headstock and tailstock. Late-model versions of the ML7R were fitted with Super 7 cross and top slide units with this change of specification seeing the title ML7R dropped and the "new" lathe renamed "Super 7 Sigma".
Stands:
Myford's original well made and decently finished "octagonal-form" 16-gauge sheet-steel (with angle-section stiffening) all-welded cabinet stand is still in production and takes up a minimum amount of room. Although only one height of stand is now offered, originally there were two, the higher being specified when a "basic" unit was ordered, the lower when a deep chip tray and 2-inch high adjustable levelling blocks were to be fitted. The stand is light enough to be carried on the roof rack of a small car and small enough to be inveigled into the back of even a small hatchback.
In the early 1950s a superb "industrial" stand was introduced: this had a much larger, rounded-edge chip tray, a locking cupboard on the left-hand side with a compartment for a coolant tank in its base, two open shelves and comprehensive electrical control gear neatly built into a front panel. Although the "Industrial" is the best possible stand for an  ML7, or Super 7 (and very sought-after second-hand) it was very expensive and dropped from the range in the late 1980s and replaced by the ordinary stand originally made for the much heavier "254" lathe.
Chucks:
Over the years just two different makes of 3 and 4-jaw chuck have been offered. Originally, English chucks marked Pratt (before 1955), Burnerd (or Pratt-Burnerd) were standard, and both 3 and 4 jaw versions could be supplied with either a thread formed directly into the body of the chuck, or for backplate mounting - the "threaded body" chucks being the better type, being designed to allow as close a fitting to the spindle bearing as possible, so reducing overhang and improving rigidity.
The internally-threaded, 6-inch diameter 4-jaw Burnerd chuck was a lightweight "half-depth" unit designed to reduce the load on the front spindle bearing and had its mounting thread well recessed into the body. In the past this model was often, but not always, marked: "Specially made for the ML7 lathe". Watch out for cracked screws on the jaw adjusters; they need only a light touch to work correctly but heavy-handed amateurs have butchered many of them. Also available was another Burnerd half-depth body 4-jaw chuck but without an internal thread and for which Myford supplied a special "recessed" backplate - which imitated, to some extent, the fitting of the threaded-body version and which helped to get the chuck as close as possible to the front spindle bearing. The Burnerd 3-jaw chuck, almost always 4" in diameter, was supplied to "Standard", "Grip-tru" or "Super Precision" specification. The "Grip-tru" is an especially sought-after version; it was based on the body and production tolerances of the "Super Precision" but incorporated a patented mechanism to allow minute adjustments of the scroll within the chuck body so that any job could be set to run absolutely true. The "Super Precision" and "Grip-tru" have always been very expensive (currently around 285 GBP for the 100mm/4" diameter) and consequently are seldom found on second-hand lathes. In recent years Myfords have turned to Polish "Toolmex" (sometimes branded "Bison") chucks and, whilst perfectly satisfactory, are not really in the same class as the much more expensive Burnerd - and unfortunately have a smaller centre hole. Sadly, Burnerd's pricing policy means that to replace the jaws in one of their products is almost as expensive as buying a complete, new, Polish or Czechoslovakian chuck. An ideal chuck set-up for a home-workshop lathe is to have two 3-jaws: one should be a top-quality item, in perfect condition, and reserved only for the most accurate work whilst the other should be a "jobbing" 3-jaw to handle rougher tasks. The 6-inch diameter Burnerd 4-jaw chuck is the perfect solution for those large and awkward jobs that would otherwise take too long to set up on a faceplate - and a good used one is well worth seeking out.
Collets:
Two types of collet were provided for use with the ML7 and Super 7, one fitted into the No. 2 Morse taper of the spindle and was retained by a simple screw-on cap that compressed the collet; the other was a conventional "dead-length" type held in a lever-action holder that screwed onto the spindle nose. The internal collets were supplied with a special compression loading tool that allowed them to be slipped into and out of the nose cap without suffering damage: it is essential to use this tool - fitting a collet by hand inevitably leads to one of its segments being broken off. The dead-length collet holder was provided with a small backplate that had to be fitted to the spindle nose and turned in-situ, so ensuring that the unit ran true to the spindle axis. Whilst later ML7s had a cast-in boss to accept the pivot stud for the lever-action closer early models were equipped with a bronze block that clamped onto one of the stiffening ribs at the rear of the headstock front bearing.
Milling Attachments:
In addition to ordinary plain and swivelling vertical milling slides three powered vertical milling attachments were produced by third-party suppliers. The Rodney and Staines were driven from the lathe spindle and the Amolco by its own motor. The former pair were, of course, mounted in front of the headstock whilst the Amolco was mounted at the tailstock end of the bed..
Approximate weights with electric motor:
Standard ML7: 185 lbs. (84 kg).  Long-bed ML7: 215 lbs (98 kg)
ML7R: 240 lbs (109 kg)  Long-bed ML7R: 270 lbs (122 kg)
Super 7: 245 lbs. (111 kg.). Long bed Super 7: 275 lbs (125 kg)
A screwcutting gearbox adds about 15 lbs
Drive Belts - Lengths required:
Super 7 & ML7R:  Headstock spindle belt A section 29.5" (use 750 mm) 
Motor to countershaft M section 33.5" (use 850 mm)
ML7:  Headstock spindle belt A section 23" (584 mm) 
Motor to countershaft Z/M section 347/16" (875 mm)
Tr-leva:  Headstock spindle (3 belts) A section 23" (584 mm)   
Motor to countershaft M section 347/16" (875 mm)
(All these belts, standard and link, are kept in stock for delivery by return of post.)
Myford ML10:
Now out of production in all its forms the ML10 at 3.25" centre height and 13" (later 18") between centres was Myford's smallest post WW2 lathe. Designed as an economical machine, especially suitable for beginners, the first one left the production line on November 14th, 1968 (though brochures had been received by dealers as early as January of the same year). Whilst a perfectly-adequate small machine tool it did lack several of the refinements to be found on the company's larger lathes: there was no gap in the bed, no tumble reverse, the backgear was carried on a sliding pin and the headstock clamped rather than bolted to the simple, flat-topped, box-section bed casting.  It occupies 35.75" in length (an ML7 was 42") and around 22" in width (almost identical to an ML7). The countershaft/motor-unit on pre September 1985 models was a separate assembly that had to be mounted on the bench, behind the lathe, with an adjustable "over-centre" belt-tensioning device to couple them together. Later machines were fitted to cast-iron raiser blocks, the one at the headstock end being extended rearwards to carry the base of the countershaft - which had the effect of turning the lathe and its drive system into a self-contained unit.
Six spindle speeds were provided, three direct-drive and three backgeared. The ML10, unlike most of its European and Far-eastern competitors, had a proper, robust backgear assembly (the backgear bull wheel on the spindle was identical to that used on the ML7) and, so equipped, a very powerful drive was available with 6 speeds down to as low as 25 r.p.m. that enabled it to cope with large diameter jobs. In addition, instead of miniature (and expensive) "Gates" belts Myford chose to use reliable, full-sized, inexpensive and easily-obtained V belts.
ML10 Headstock:
On early and late machines the headstock was different. The first model, with six speeds and a maximum of around 840 rpm, had a hardened spindle that ran directly in split bearings formed as part of the headstock casting. This combination of hardened steel running in cast iron (partially self-lubricating due to the free graphite found in the latter) is excellent from the wear point of view - and I have yet to find any ML10 with the headstock bearings in poor condition. You may be quite confident that this design principle is correct - tens of thousands of American South Bend (and other makes) have been constructed in this way - and are still going strong. The bearings on the ML10 were split on one side only and provided with a clamping screw; the space between each split was filled with a thick shim to provide a firm surface onto which the top cap could be pulled down. If the headstock bearings appear to be in correct adjustment it is important not to fiddle with them; simply ensure that they receive regular lubrication - and under no circumstances remove the shims. It is possible to vary the speed range of an ML10 by changing the size of the electric-motor pulley, but do bear in mind that the maximum recommended speed of a plain-bearing ML10 is 1280 rpm. Later machines, produced from January 18th, 1978, (from machine V137261) were fitted with roller-bearing headstocks that, although provided by the factory with the same speed range as the earlier machine, can easily and safely be adapted by their owners to run as fast as the later "Speed 10" version (see below for details).
ML10 Changewheels, Screwcutting and Metric Conversions:
Originally supplied in both full metric and imperial versions the latter is by far the most easily-found second-hand. To convert an imperial machine to metric screwcutting required only two 21t changewheels in addition to the normal set - whilst to convert the rest of the lathe to a metric specification needed only the substitution of the inch-calibrated cross and top-slide feed screws, nuts and micrometer dials with their metric equivalents. The lack of a tumble reverse meant that a reversing stud was necessary to cut left-hand threads; the changewheels and their mounting studs, fastened to a simple, single-slot banjo, were identical to those on the ML7.  The leadscrew pitch was the same as the 7 Series lathes (8 threads per inch) and was available fitted with an optional and very useful dog-clutch that allowed the leadscrew drive to be instantly engaged and disengaged..
ML10 Compound Slide, Apron and Saddle Assembly:
Although the cross slide was a little smaller than that on an ML7, the micrometer dial, hand-wheel and standard toolpost were identical. The T slots were spaced the same distance apart, which allowed a standard ML7/Super 7 vertical milling slides to be used, but the 4-way toolpost and rear toolpost were unique to the machine. The apron hand-wheel was geared directly to the leadscrew and incorporated a thread-dial indicator. Because the direct gearing caused the saddle travel to be rather "high-geared" (i.e. you turned the handle a little, and the saddle moved a lot) the leadscrew was provided, as standard, with an un-graduated handle at its right hand end; used with the clasp nuts engaged this was able to provide a much smoother and steadier saddle movement. From machine number V167714M, on the 27th of March 1993, the previously optional-extra 'long cross slide' was fitted as standard.
Speed 10:
On the 4th of May 1979 a modified "two-speed" countershaft unit was introduced that carried an eccentrically-mounted top shaft, with a double-step V-belt pulley drive from the motor; this doubled the number of speeds to 12 (of which 10 were officially sanctioned as safe to use) with a range from 48 to 2000 r.p.m. This new model,  the "Speed 10", was identified by the prefix "VS" and the first down the production line carried the Serial Number VS143202M. Just one month later, on the 6th of June, an attempt was made to bridge the gap between the ML7 and ML10 by introducing the 18-inch capacity between-centres long-bed Speed 10 - the first example being  numbered VSL144264.
A useful little machine, the ML10 was perfectly capable of tacking most jobs that the model or development engineer would wish to attempt, the only drawbacks being the simplicity of its construction - and basic controls. A friend, who is a full-time experimental and development engineer, bought one in his impecunious days and held on to it for twenty-two years, finding it indispensable for all his small turning. The last incarnation of the ML10/Speed 10 was the "Diamond 10", introduced on November 27th, 1993 and only marketed from the factory. A comparatively rare machine on the used market, the 10 sold in fewer numbers than the larger models - although, to be fair, the latter did have a twenty-two year start
Used MYFORDS can often be found for sale on this page:
Copyright: Tony Griffiths