Time to Shape Up
When the term “shaper” is heard these days, most people in the U.S. and Canada think of the manually fed woodworking tool that uses a powered rotating cutting head. (The machine is known as a “spindle moulder” in the United Kingdom.)
The metalworking machine tool of the same name is not as well known among modern machinists, but it was once held in high esteem and found in a sizeable percentage of machine shops. Advancements in milling machine technology have made shapers obsolete, but many old school metalworkers still use them for specific tasks, such as cutting internal keyways.
The shaper is an adaptation of the metal planer, though much smaller, and instead of a workpiece moving on a large table under a stationary tool, the shaper applies a moving cutting tool to a stationary workpiece. Primarily used for creating a flat surface, a shaper can also be used to machine irregular shapes that weren’t able to be readily produced using other machines from its era.
What a lathe is to helical machining, a shaper is to linear cutting. With the workpiece clamped securely to the table or in a vise, a reciprocating ram moves a non-rotary cutter called a single point cutting tool back and forth across its surface. The cutting usually takes place during the outward stroke, with a quick return mechanism bringing the ram back. During the ram return, a ratchet gear and pawl mechanism advances the workpiece laterally to the next cutting position.
History of Metal Shapers
The first notion of the shaper appears to have come from the mind of Sir Samuel Bentham, a British naval architect and mechanical engineer. He received a comprehensive patent in 1793 that introduced eleven concepts in woodworking, affecting almost every process and machine still in use today. His patent described such diverse ideas as a reciprocating vertical saw, practical means of holding and adjusting workpieces in cutting machines, ways of advancing a cutter or workpiece towards the other, making plywood from wood shavings, and methods of removing chips from a saw or cutter using air or a chip brush. He foresaw that some of his innovations could be used in metalworking as well as woodworking, such as a concept for a reciprocating planing machine.
Between 1814 and 1817, Matthew Murray, Richard Roberts, and James Fox all independently developed the earliest metal planers, while the first metal shaper was invented by Scottish engineer James Nasmyth in 1836. Nasmyth’s shaper used a reciprocating cutter to plane surfaces, cut keyways, and do other straight-line machining. Nasmyth called his steam-powered shaper a “steam arm” and continued to invent things, such as the first machine grinder in 1837 and his famous steam hammer in 1839.
In 1896, American Edwin R. Fellows designed and built a new type of gear shaper that could mass produce almost any type of gear, making it indispensable in the brand-new automotive industry that required reliable gear transmissions. Half a century later, machines produced by the Fellows Gear Shaper Company were in high demand by defense contractors during World War II.
The shaper was in its heyday from the mid-1800s to about a century later. Advancements in machine tools in the latter half of the 20th century superseded the shaper, but the machine remains popular with hobbyists, as well as some machine shops, including tool and die makers.
Types of Shapers
Shapers can be classified in different ways, whether by a design feature, the drive mechanism, or the action of the machine during the operation. A single machine can be referred to by more than one term. The following are some of the more common designations:
“Rival the Hand Work of the Most Skilled Mechanic”
In his 1883 autobiography, James Nasmyth explained what motivated him to invent the shaper. He said that while planing machines helped perfect and economize the production of machinery, they really were intended for use only in large scale manufacturing, leaving “a very considerable proportion of the detail parts” to be done by hand using things like chisels and files. “The results were consequently very unsatisfactory, both as regards inaccuracy and costliness.”
He “designed a simple and compact modification” of a planing machine that could adapt its benefits “to the smallest detail parts of machine manufacture.” The device, he wrote, “should enable any attentive lad to execute all the detail parts of machines in so unerring and perfect a manner as not only to rival the hand work of the most skilled mechanic, but also at such reduced cost as to place the most active hand workman far into the background.”
Nasmyth felt his “contrivance” would eliminate “the great amount of time that is practically wasted and unproductive, even when highly-skilled and careful workmen are employed.” He noted that such craftsmen have to stop work frequently “to examine the work in hand, to use the straight edge, the square, or the calipers, to ascertain whether they are ‘working correctly.’ During that interval, the work is making no progress; and the loss of time on this account is not less than one-sixth of the working hours, and sometimes much more; though all this lost time is paid for in wages.”
Like all the great innovations of the industrial revolution, the shaper was invented to solve problems of accuracy and cost inherent in manual metal crafting. While now supplanted by more modern pieces of technology, the shaper will always hold a revered spot in the hearts of true machinists who love the history of their craft.