email: tony@lathes.co.uk
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EXE Surface Grinder

EXE Surface Grinder Page 2   EXE Lathes Home Page   

EXE Grinders: new spare parts are now available: Phone 07784-332583 

One of only a handful of dedicated, miniature surface grinders made world-wide, the British-made EXE joins a select group with some of the others being the  American Sanford, made in New Jersey; the pre-WW2 Herbert "Ball-bearing Bench Surface & Die Grinder"; the fine French Lipmec LIP 515, the rare Bulova and the Grenby by an American company (better known for their cylindrical grinders), whose slightly larger table-top unit appears to have been adapted for the Australian Macson and, in recent years, also produced in Taiwan and China and sold under various brand names including Harbor Freight,  Richyoung and Tormach - the latter, produced to a higher level of accuracy and finish than the others, is available with automatic feeds and has travels of 6 by 12 inches - travels for the hand-feed Grenby are not known.
Cast from a Mehanite iron and with its handles in aluminium, the EXE was first manufactured in the early 1950s and remained available until the late 1990s. It was offered in two forms: one for bench mounting, the other mounted on the maker' robust and enormously heavy cast-iron cabinet stand that including, as an option, a neat, integral dust-extraction system (though eventually this was to be dropped and just the basic stand provided. A motor-fan unit was mounted in the base with a pipe extracting dust through externally-mounted filter bags - fitted with a shaking mechanism - for cleaning. The plain type stand (also in cast iron) is easily distinguished from the filter type by a hinged door on its front face.
Unlike many surface grinders of its era, the spindle ran not in super-precision plain bearings but in a detachable housing that held pre-loaded, angular-contact ball bearings. To encourage speedy and safe wheel changes to be made, the grinding wheel was mounted on a quickly-detachable collet - the standard wheel on later machines being 7" x 0.5" x 1.25". At some early in the production run, the casting holding the spindle was increased slightly in length, though by how much is not known. Able to stand intermittent overloads of 50%, 0.5 h.p. 3-phase motor provided, via a smooth-running flat belt, two spindle speeds of 2,700 and 3,100 r.p.m. - the change being made (rather inconveniently) by interchanging the drive and driven pulleys. Like most grinders, the EXE had a balanced motor, this being tested complete with its pulley to ensure the smoothest possible running. As any deficiency in the balance of rotating parts of a machine tool - including the drive wheels - can be transmitted to the surface finish of a job, special care is needed when handling rotating components from any grinder - even small chips and worn belts can cause trouble and, if the machine has been standing for some time with the belt in place (and chemically reacting with the pulley), it's best to fit a new one. Want to check balance? Put a cup of water on any flat surface and switch on; there should be no ripples or disturbance at all. The makers also listed a special high-speed spindle assembly that ran at 15,000 r.p.m., this being intended to make use of very small wheels that opened up the possibility of grinding awkward slots and recesses.
A few of the high-speed heads are still available - phone 07784-332583 for details. It was also possible to specify, at extra cost, a range of different pulley sizes to vary the speeds of both the ordinary and high-speed spindles.
All slideways were hand scraped to a perfect fit and the 12" x 6
3/8" table - intended for hand operation only - ran on V and flat slides with longitudinal and traverse travels of 13.5 inches and 7 inches respectively. Longitudinal drive was by a rack and spiral pinion - with the all gears on the machine hand lapped to a perfect fit; however, the table drive gears, (with the pinion set at an angle to promote a smoother and easier motion) were given a trace of backlash, this preventing the microscopic table rise that would have occurred if the gears had been meshed play-free.
Mounted on double V-ways, the saddle was driven in and out by an enclosed 10 t.p.i. screw with its bronze or cast-iron nut adjustable to take out backlash. While simple end stops to prevent the table overrunning the knee were fitted as standard, as an option a very useful adjustable stop system could be provided; this mechanism consisted of a flat steel bar, perforated with a line of holes, fastened to the front face of the table and able to mount a casting that could be flipped into two positions. The first position brought into line spring-loaded plungers, one set at each end of the unit, that allowed a rapid table reversal, the second position used a pair of small anvils that acted as dead stops - these being essential, according to the maker, when the high-speed spindle was in use grinding vertical surfaces. As the stop was hinged, it could be swung out of the way to allow the table to be moved for the checking or measuring of a job.
Clearance to the table beneath an unworn 7-inch wheel was 9.25 inches - and to the standard-fit Eclips magnetic chuck 6 inches. Vertical travel of the head was 9.75 inches, its movement being by an enclosed screw and bronze nut supported on a ball-thrust race nut, the operating handle being engraved on its periphery with lines set 3/16" apart, each division equalling a travel of 0.0005".
The bench model weighed a massive 620 lbs and the cabinet version, complete with dust-extraction equipment, 1360 lbs (over a half-ton) and no, it will not fit in the back of a standard-issue Euro Hatchback - although the bench version will.
To give some idea of the machine's quality, in 1957 a Myford ML7 lathe cost a little over £50 - whereas the EXE, at £447, was over nines times as much as a bench model and on the stand ten times the price, at £598. Although surface grinding machines are rarely found in smaller workshops, the compact little EXE is one of the few available that would make an ideal addition to the machine-tool collection of the more enthusiastic amateur.
Standard equipment supplied with each new grinder included a 10" x 5" magnetic chuck, one grinding wheel, a diamond holder for wheel dressing (but not the diamond), two special spanners and an oil gun.
If the serial number is found, by adding 40 to the first two digits, the year of manufacture is revealed e.g. 29 add 40 would be 1969. If the number has as "R" suffix, this shows that the grinder had been sent back to the works for reconditioning.
EXE also made, amongst a range of engineering accessories, several models of high-quality and rather interesting and unusual plain-turning and backgeared lathes, a number of glass-turning lathes, eight sizes of NULOCK boring bars of split-square-housing type and Keats angle plates (faceplate-mounted V-blocks).

High-resolution pictures - may take time to open



EXE precision miniature 12" x 6"  surface grinder

High-speed grinding spindle. This unit interchanged with the standard spindle and was able to run at up to 15,000 rpm. a very useful adjustable stop system could be provided; this mechanism consisted of a flat steel bar, perforated with a line of holes, fastened to the front face of the table and able to mount a casting that could be flipped into two positions. The first position brought into line spring-loaded plungers, one set at each end of the unit, that allowed a rapid table reversal, the second position used a pair of small anvils that acted as dead stops - these being essential, according to the makers, when the high-speed spindle was in use grinding vertical surfaces. As the stop was hinged it could also be swung out of the way to allow the table to be moved to allow the checking or measuring of a job.







EXE Surface Grinder Continued on Page 2   EXE Lathes Home Page   

EXE Grinders: new spare parts are now available: Phone 07784-332583 

EXE Surface Grinder
email: tony@lathes.co.uk
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