At one time the planer was considered an indispensable part of any machine shop, large or small - often being used to machine several identical jobs "ganged up" on the table - machine tool beds and other larger castings being typical examples, as shown here in the American Hendey factory. Today, planers they are still in use machining huge castings for a variety of industries for, using inexpensive tooling they can machine large components with relative ease and considerable accuracy. Some examples are huge, with beds fifty or sixty feet long and able to accommodate work sixteen feet high, and fitted with either fixed or pivoting grinding or milling heads in place of the ordinary "clapper-box" tool holder - this type being known as "planer-millers" or "planer-grinders" or, in some regions as the "plano-miller" and "plano-grinder". On larger types it's common to find more than one toolbox fitted, the cross-rail can often carry two or more, side by side, with several others sometimes mounted at the bottom and sides of the cross-rail support columns.
Some planers are made open-sided, and able to accommodate even larger jobs and, as so many specialised machining operations can be undertaken, it is often difficult to differentiate between planers and true millers - examples made by the huge American Niles-Bement-Pond Company have included: Multiple Spindle Horizontal Milling Machines, Horizontal Slab Milling Machines, Horizontal Slab Milling Machine, Rod Milling and Fluting Machine, Duplex Milling Machines, Forge Milling Machines, Plate Planers, Rotary Planers and End Milling Machines. Although the name changed according to the specific use, the principle of operation remained essentially the same, a long table sliding beneath (or between) single or multiple static or powered cuttings heads.
Other variations on the theme include "Pit" and "Breast" planers where the workpiece rests in a pit (or on a table) and the columns carrying the cross-rail and toolheads travel over it. These massive machines are generally reserved for the heavier kinds of armour-plate work intended for nuclear power stations and warships.
Planers have been made in almost every size increment imaginable, the smallest being tiny, hand-operated units designed for bench mounting and, although rare (and now highly sought-after), those suitable for an amateur's workshop do occasionally turn up. Not only do they have an engineering novelty and historical value, but because they are still capable of their original task - the economical machining of large components in a limited space - are still a most useful machine to have in the workshop of the serious amateur. In addition, as they work, they have a strange and rather beautiful hypnotic motion.
Milnes planers were not made in great numbers - the company's speciality was high-class lathes - nor in a wide variety of sizes, with just three models identified: one from around 1890 with no known model designation, just the maker's description of a 24-inch stroke (it's likely to have been offered in different sizes as well); the No.1 hand-operated model (that appears to have been unchanged from its introduction in 1910 to the end of production) and the No.2, this being fitted at first with a relatively simple drive system but then one of greater complexity that made the machine entirely self-contained with automatic reversal of the table and indexing of the cutting tool.
Further down the page can be seen pictures of a beautifully restored and working No.2 Milnes from the 1920s.
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