A woodworking machine similar to a stationary spindle molder or Shaper-- or overhead router, but -- at the spindle, using a much higher rotation speed, to produce more highly-finished work. Since the 1930s -- the Stanley-Carter router, discussed below -- a portable hand-held version of this. A versatile power tool, a router does many woodworking operations.
Because of its high speed -- operating at from 8,000 to 24,000 r.p.m. -- when it's used with a Router Bit, especially a Carbide-Tipped router bit, it produces a very smooth surface that requires little sanding.
Fitted out with readily available accessories, and/or home workshop-made jigs and fixtures, a router is adaptable for many specialized woodworking operations, including a Power Plane, a Spindle Shaper, a hinge Mortiser or as a Dovetail Cutter.
With editions published between 1973 and 1982, this Sears Craftsman booklet illustrates and describes what opportunites and options woodworkers -- especially amateur woodworkers -- had three decades ago.
In a manual tightly packed with photographic images, colored drawings, and clear text, the British-based writing team, Albert Jackson and David Day declare:
Most power tools are no more than mechanized versions of their hand-field predecessors. They take much of the graft (sic) out of woodworking, but the business end of these tools remains much the same -- a saw cut is still a saw cut, a hole is just hole, and a screw will do its job well whether it is inserted by hand or with a power screwdriver. The power router, on the other hand, is in a different category. This is a tool that has revolutionized the home workshop. It has all but replaced the specialized hand planes used for molding, rabbeting and grooving, and works with a degree of accuracy that was once only the prerogative of the most skilled craftsperson. Combine all these functions and you can cut a range of woodworking joints, follow templates, trim plastic laminates, even carve wood sculpture. The remarkable power router is nothing less than a miniature machine shop.
Source: Albert Jackson and David Day Good Wood Routers Cincinnati: Betterway Books, 1996, pages 6-7.
While common sense tells us that "router", as a term identifying this machine is straight-forward, dictionaries, especially the Oxford English Dictionary -- the source I consult first -- are disappointing, because the first use of the term identifying the power router, i.e., Kelley, are lacking from their accounts.
The concept of a "router" as a tool -- but as a hand tool -- stretches back into the 19th-century, where it was considered a fixture that is "shop-made". At least that is the gist of the descriptive text that accompanies the wonderful images published in the 1901 Cassell's Cyclopedia of Mechanics.
Fig. 1 shows a piece of circular moulding, worked on the flat surface. First cut out the required shape or plan: get the piece equal in thickness and parallel in width. Sink squares as shown by dotted lines, taking out No. 1 square first, and so on; then, with a router, as shown in Figs. 2 and 3, work the mouldings from the outer edge. To work the rebate at 5 (Fig. 1), place the piece in the bench chops [sic] C (Fig. 2) and work in the same manner as shown for the small member on the inner edge. Fig. 3 shows how the moulding may be worked on the edge of a shelf bracket. The router can be bought at a toolshop [sic], or made with a piece of hardwood and a piece of thick steel. B (Fig. 2) and A (Fig. 3) show the cutter.
The fence C (Fig. 3) may be either of brass or iron slotted so as to be adjusted.
Source: Paul N. Hasluck, ed., Cassell's Cyclopedia of Mechanics London: Cassell, 1901; note the subtitle:-- "containing receipts, processes and memoranda for workshop use based on personal experience and expert knowledge, with 1,200 illustrations and an index of 8,500 items". Anyone looking at "beyond a superficial glance" at my website will soon detect that Hasluck is one of my major sources for documenting information on late 19th-century woodworking issues, especially matters that relate to tools.
When, exactly, the term "Router" -- i.e., as reference to the current popular tool -- came into usage to identify a "power router" is wrapped in mystery. Keith Rucker has found bits of evidence -- advertisements from from 1911 to 1929 -- in the magazine Wood-working. I owe the Paul Hasluck find above to an Internet search, using the "Google Books" search engine, simply for locating the occurence of "router" in texts of publications before 1900.( For tracing the etymology of this term, the Oxford English Dictionary is not very useful, as the examples below demonstrate).
Another form of vertical boring machine is known as a router or recessing machine or overhead spindle moulder.
Source: William Barr McKay Joinery, London: Longmans Green, 1946, page 24.
The router has taken over a great deal of the lighter work up to 1 in. or 1 in. thick which was formerly done on the spindle-moulder....Portable electric router ... This machine works on the same principle as the overhead-router.
Source: W. E. Kelsey Carpentry, Joinery and Woodcutting Machinery 1954, pages 517, 546.
The electric hand router -- if you can operate a 60-pound tool by yourself -- has been around for over a century.
(The image of the Kelley router comes from the Patrick Spielman book, The Art of the Router: Award Winning Designs, 1999 -- permission to post granted by phone, 9-17-2007.)
As early as 1905 the first commercially produced router -- three phase -- was marketed by the Kelley Electric Machine Co. of Buffalo, New York. That firm -- incorporated with an capitalization of $25,000.00 in October of 1908 -- had three directors: Guilford W. Franicis, W. Morse Wilson, and George L. Kelley.
Source: New York Times, October 24, 1908, page 12.
George L. Kelley, a resident of Buffalo applied for a patent for a router in 1906; the patent was granted in 1908. The patent -- the first page is pasted below -- was assigned to Stevenson Machine Co. (By "assigned" is derived through "mesne", a technical term in law, meaning "middle" or "intermediate".) "Given the purported 1906 genesis of the Kelley Electric Machine Co., router", Keith Rucker speculates, "it is likely that Stevenson Machine Co. was a predecessor of Kelley Electric Machine Co."
For more details about these historic events, read the Iframe below:,
1. American Router & Mfg. Co., Kelley Electric Machine Co., & Mattison Machine Works
The Kelley Electric Router is a portable, bench, machine fitted with a motor of the universal type which operates on either direct or alternating current. It is used for stair routing, panel raising and sinking, inlaying and a large variety of similar work. One or two cutters are employed and are driven at 6500 R. P. M. by the 1 H. P. motor. The cutting tools are housed within the skirt of the motor housing.
Not pictured, the "Hunter" Electric Stair Router built by the American Router & Mfg. Co. is used for stair and similar routing. It embodies a vertical motor of the reversible type which drives the cutter at 3400 R. P. M. in either direction so that the cut may be with the grain.
The Mattison No. 199 Line Cutter is a portable electric driven tool built on a frame similar to that used on the Mattison No. 195 Electric Trimmer and used in connection with a "planted on" template for routing out lines of any shape for inlaying on furniture and cabinet work. The vertical motor is mounted in an aluminum casing with skirt which rests on the template. The routing bit is carried in the vertically adjustable motor spindle. Motor can be fitted with two spade handler.
2. Motor Routing Tools
The R. L. Carter Co. tool, illustrated herewith, is designed for line routing, inlay v grooving, veining, two-tone work, etc. It embodies the same 1, H.P., 15,000 R.P.M. ball bearing motor as used in the Carter Shaping Tool (772). The motor casing is externally threaded and adjustably mounted thereon is an aluminum skirt which travels on the face of the work. Cutter is controlled by a stationary guide which contact a "planted on" template. Range is to carry bits up to 1/4 inch diameter and cut to a depth of 3/8 inch. The tool is 6 inches high and 4 inches in diameter. Net weight 5 pounds.
The Mattison Machine Works' No. 199-A Router is similar to the Carter tool and used for the same class of work. This tool, illustrated herewith, involves a special motor of the universal type in a dust-proof casing.
Here are two pdfs to check for some early attempts toward putting routers and/or the spinoff versions on the market, primarily for cabinetmakers, but not (yet) amateur woodworkers:
(1) Selected pages from a 1929 "series E" Woodworkers Tool Works Catalog
(2) A 1935 Stanley Router Shaper Catalog, # 61.
Today's routers are straight-forward: they are powered by a universal motors, controlled by "on/off" switches, a base for stability and maneuverability, handgrips for control, and a lever for lowering the rotating bit into the work, called "plunging the router". Equipped now with variable speed controls, rotation can range from 8,000 to 24,000 rpms. (Shaper speeds vary from 6,500 to 10,000.)
All common routing tasks can be performed with ease with the Plunge Cut Router: Grooving, rabbeting, recessing, veining, and profiling on all types of wood and plastic:
Veining and Grooving. A method of decoration, to "vein", "groove", "rabbet" and/or "dado" is -- using a template as a guide -- to cut fine, decorative lines on a workpiece's surface.
Source: [Anonymous] How to Get the Most Out of Your Homeworkshop New York: Popular Science Publishing, 1946, page 79
Inlaying. In general, it may be said that inlaid work is of two kinds. Lines are straight borders glued up in many different designs in widths from 1/16 inch up. Insets are center or corner decorations glued up of many small pieces of wood of different color and shape.
Molding Edges. Small moldings and edges of table tops, picture frames, etc., are shaped on the router.
Gains, Mortises, and Dovetails. Gains for hinges and shallow mortises are made with ordinary straight routing bits. For mortising of greater depth, different templates and jigs have been created. Dovetailing is done with a special bit and special metal guides.
Experience using routers and shapers shows us quickly that that two capable tools differ in several ways, primarily in speed of rotation, scale of project, but also, that in many operations, they are interchangeable.
That is, woodworkers who own both tools often need to debate which of these two tools are used for the performance of a woodworking task. For example. putting a Profile -- or, Molding, on the edge of a sideboard's 1-inch thick top can be done by either tool. However, putting the profile on a 1-inch thick oval- or circle-shaped table-top might be accomplished more easily with a large router, rather than a shaper.
The two authorities quoted below, Nick Engler and Lonnie Bird, each give their take on the distinctions between routers and shapers:
Only use a shaper spindle router accessory in a router with a variable speed control — either a control that has been built into the tool itself, or an external control that you can plug the router into. Set this control for no more than 10,000 rpm — the top speed of many shapers — when using the spindle accessory. Most shaper cutters are designed to operate within shaper speeds, while many routers spin more than twice that fast. At excessive speeds, the cutters may fly apart, peppering you and anyone who happens to be standing nearby with shrapnel.
Source: Nick Engler, Routing and Shaping: Techniques for Better Woodworking. Emmaus, PA: Rodale Press, 1992, page 4.
... A good-quality shaper will be able to run at multiple speeds to accommodate cutterheads of various diameters. At minimum, the shaper should have at least two speeds, with a low speed no higher than 7,000 revolutions per minute (rpm). A large industrial machine usually has several speeds, with a low of around 3,000 rpm.
A small-diameter cutterhead has a slower rim speed than a large-diameter cutterhead when run at the same rpm, and so a higher rpm is needed to increase the rim speed to produce a smooth surface. (This is one reason why a router runs at such high rpm.)
On the other hand, because a large cutterhead removes so much stock in a single pass, it must be run at a lower rpm to reduce the rim speed. This way the surface doesn't get burned. Running a large cutterhead too fast is unsafe (these cutterheads have a specified maximum rpm) and may burn or burnish the stock.
(Burnishing causes the wood surface to become glazed. It can occur when the feed rate is too slow for the rpm of the cutterhead.)
Source: Lonnie Bird, The Shaper Book. Newtown, CT: Taunton Press, 1996, page 13
"The modern router", claims Anthony Bailey, Routing For Beginners, 1999, page 4, 2012, page 14 "descended from the fixed-head machines". With this claim, I think that Bailey is, in the idiom of today, "onto something", although in his book he doesn't elaborate on the point. Nonetheless, his statement stimulates our thinking on the matter, especially when you consider the Workace "shaper" introduced in 1929 by the J D Wallace Company.
For example, check out my post on the "royal-treatment" given the Boice-Crane floor shaper in Popular Homecraft in November, 1930. For me, side-by-side, the two images have remarkable similarities. Yes, one is floor-standing, the other bench-top, comparison that is --perhaps -- a "stretch", but -- taken together -- the round cast-iron tables on both models, the fact that Popular Homecraft sees the B-C shaper as appropriate for home workshops, make the analogy seem reasonable. (Puzzling, though, is why, in the 1935 Boice-Crane catalog, the floor shaper is absent, suggesting that it had a short-life span.)
This "Smoking-gun" evidence about the truth of Bailey's claim about a linkage between the modern router and the shaper is available, but -- without more evidence -- I hold back about drawing any firm conclusions.
Below, for example, is a digitized reprinting of the page from the 1932 J D Wallace Woodworking Tools catalog.
But, strangely, this shaper is not in the 1933 J D Wallace catalog.
... in large plants, small shops, schools, hobby shops, maintenance departments, pattern and cabinet shops and furniture repair departments.
In the large plants the Workace Electric Shaper supplements the larger equipment -- handles all the lighter work and short runs at an enormous saving in set up time, power and in-vestment. It is portable, can be taken to a job -- saves steps.
It operates off a light circuit, can be economically run at any time independently of the other plant equipment -- that is a decided advantage in equipment of the Wallace and Workace type. The capacity of the Workace Electric Shaper, the speed and precision with which it operates, the small investment and low operating and maintenance cost, places the small shop, pattern shop or cabinet shop, furniture repair departments. schools and hobby shops in a position to do all kinds of shaping efficiently and economically, to handle long runs or short runs, specials and repairs; any type of moulding, grooving, beading, shaping and tenoning.
The Workace Electric Shaper comes complete as illustrated on the left, including two steel shaper collars 2" dia., 3/8" thick bevel grooved for knives; four spacing collars 1/3" thick; locking pin. 10 ft. lamp cord and separable plug. Motor to operate on 110 or 220 volts DC and AC, 25 to 60 cycle, single phase, or 220 volts, AC. 120 cycle, three phase (7200 RPM) 1 HP., or 220 volts, AC.. 180 cycle three phase, 1 HP. (10,800 RPM). Set ups for any shape are quickly made on the Workace Electric Shaper. To facilitate short runs we have worked out a set of cutters in Nos. 2757, 2758 and 2759 which, in various combinations, make it possible to cut practically any shape. Knives and solid cutters, of course, are avail-able for long runs or shapes often made up. The Workace Electric Shaper operates from the electric lighting circuit, also available for 120 or 180 cycle, three phase. It is direct motor driven-direct, positive, powerful and economical drive; no belts to dissipate power. High speed, 10,000 R.P.M. (no load speed). Works with or against the grain; portable, easily taken to the job, saves steps. Precision ball bearing, air cooled. We will gladly submit the Workace Shaper to you so that you may try not what we claim to be the biggest value in woodworking equipment -- a high speed, powerful, accurate tool at a very modest price -- the Workace Electric Shaper. WE RECOMMEND Three or four wing cutters for cuts used frequently, saves set-up time, quotation on request. Knives are available in shapes shown on opposite page. For quick set up on short runs of various shapes we suggest cutters Nos. 2757, 2758 and 2759 illustrated on opposite page. Guard No. 2714 and Fence No. 2713. These items are optional and available at a small extra cost.
Source: J D Wallace Woodworking Tools Catalog 1932
Below, the shaded box reprints the brief piece by the editor of Industrial Arts Magazine, suggesting that the Wallace high-speed shaper was introduced in 1929.
The J. D. Wallace Company, 134 So. California Ave., Chicago, Ill., has announced a new Workace electric shaper, something entirely new in the popular priced and portable line of shapers.
The Workace shaper is equipped with ball bearings. It is motor driven, and adequate means for lubrication are provided. In this machine, the belt has been eliminated, thus slipping, slowing down of operations, and loss of power is avoided. The shaper is mounted on a table with a screw arrangement, which permits it to be raised or lowered. It can be locked securely in any position by a handwheel. The spindle is a steel shaft 5/8 in. in diameter, which extends 3 5/8 in. above the table top, and provides a capacity of 2 1/2 in. between two steel shaper collars, or 3 1/4 in. when using solid cutters. The machine is provided with a General Electric Universal motor, which can be used on an ordinary lighting circuit, 110 or 220 volts, d.c., or 25 to 60 cycle a.c. It weighs only 42 pounds and stands firmly on its own base without fastening.
Source: Industrial Arts Magazine 18 September 1929, page 31A.
With the text and image of the J D Wallace Workace shaper (above), including its direct-drive universal motor and 47 pounds, we have the ideal setting for another breakthrough in the development of the hand-held high-speed router. However, until I find more conclusive evidence, I remain skeptical. I think that perhaps the speed of the spindle rotation -- 13,000 rpm -- was too fast for the cutters that existed in the late 1920s. (Normally, spindles on shapers operated by amateur woodworkers rotate at two speeds -- governed by the two-stage pulleys on the spindle's end, below the shaper's table surface, that are belted to the motor. Operating the machine at higher speeds -- especially with larger diameter cutters, raises the danger of the machine causing problems, including injury to the operator.)
Adapted from the entry on this machine by Dave Potts on www.owwm.com:
top of this machine measures 12 inches square and has a round
throat/hole with a shoulder to permit the use of smaller throat plates.
The router motor included is one of Stanley's smallest types-- the hand
shaper model, and is held in place with a pivoting bracket that permits
tilting the router bit. The two leg brackets that are bolted to the
3/8" plate-steel top are identical, and are marked with casting number
C 1780. The unit weighs close to 50 pounds.
While no fence is shown with the machine, Dave Potts, who owns the machine, notes that there appears to be remnants of a guard that mounted from below the table.
Two patent numbers are stamped into a plate mounted on the machine, both assigned to Ray L. Carter c. 1925. Patent # 1532683 was for a portable shaper and mortising machine, and number 1566824 was for a portable wood shaper http://www.google.com/patents?id=lsllAAAAEBAJ&dq=1532683 http://www.google.com/patents?id=pzdaAAAAEBAJ&dq=1566824
As a disclaimer, Potts notes that neither of the patents in the links above describe the machine pictured. For the sake of perspective, the picture above is "with this router table placed on top of a floor-standing Stanley Router/Shaper table S5A that I recently restored and use on a regular basis". http://owwm.com/PhotoIndex/detail.asp?id=5996.
The text below -- it comes from Herman Hjorth's article on the router -- reads "funny" today, perhaps, when we are confronted with terms such as "router machine", or that heavy-duty routers "mostly resemble drill presses".
(During the first half of the 20th century, Herman Hjorth was a leading figure in Industrial Arts and woodworking circles. Notably, he authored Principles of Woodworking in 1930 and Modern Machine Woodworking, Bruce, 1937, but in the revised edition, 1960, William F Holtrop was senior author, suggesting that by that date, Hjorth was too elderly for the task of managing the manuscript of a text on power woodworking machines. It happens to all of us, let me assure you.)
The production router that Hjorth speaks of has passed from the scene. Big routers like the ones pictured are used to cut patterns out workpieces, guided by templates. They are usually called pin routers -- see below -- because they normally are set up with a pin co-axial with the cutter; the pin rubs against the template that is fastened to the workpiece. They are also called over-arm routers.
The biggest maker of pin routers was Onsrud Machine Works. OMW made machines that resemble Hjorth's illustration. (I am indebted to Jeff Joslin, one of the editors of Old Working Machines (www.owwm.com) for this information.)
The router machine in its heavy-duty production form [writes Hjorth] is a type of machine that mostly resembles a drill press.... Production routers -- large machines equipped with a table that can be raised or lowered ....
The router arm extends to the center of the table. In most machines the revolving part is connected to the driving mechanism with a belt, which gives the router a speed from 10,000 to 20,000 R.P.M. The table can also be raised or lowered with a treadle and the length of the stroke can be set beforehand. Some routers also have a chuck for holding a shaper spindle. In this case the shaper cuts are necessarily made from the top while a regular shaper cutter projects through the table and cuts from below.
Among amateur woodworkers today, as routers "go", my collection doesn't really "amount to a hill of beans", as they say, and so, the question, "why bother?" Only because, taken together, the three suggest an historical range, stretching from the router's beginning as a "tool" in the home workshop through technological advances -- the "soft start", the "plunge mechanism", the improved collets, the half-inch shank -- to closer to today, where -- in the woodshops of amateur woodworkers -- the router is probably the most popular tool and -- because of its appeal as a tool that can create quickly so many interesting shapes in wood -- may be a "first purchase" for the "inexperienced, but eager beginning woodworker".
Truth be told, these last paragraphs are what might be termed "unintended consequences". In speculating about why routers are a "first purchase" by prospective amateur woodworkers -- largely because of my gut feeling that many wannabes do buy routers first -- my common sense jumps in with a rejoinder, "Does it matter? We all start somewhere, and, if a router as a first purchase launches a successful hobby, i.e., a satisfying one, that results in many finished projects, is it not a good thing?"
Today, for example, the veteran writer of books and articles on woodworking, R J Decristoforo, intones that, "early in the 21st century, a hand-held, portable router is often the first power tool purchased by the beginning amateur woodworker"
...There's little point to touting the virtues of the portable router because, "Is there a woodworker with a soul so dead he never to himself has said, 'I love my router'." The mechanics of the router haven't changed but improvements continue to make it an exciting tool, especially the plunge feature.
Source: R J DeCristoforo, The Jigs and Fixtures Bible: Tips, Tricks and Techniques for Better Woodworking Cincinnati: Popular Woodworking Books, 2001, page 17. First published in PW, April 2000, page 17.
To wit: the professional cabinetmaker, Gary Rogowski, argues that the router is one of the "five essential tools for woodworking today". Wannabe woodworkers could not do better for themselves than to read (and heed) Rogowski's sage advice.
Many routers -- like my Elu, below on the left -- have a mechanism that allows "soft start", meaning that rather than jumping immediately to the high speed, the motor works up to the speed more gradually, a feature which gives the operator more control on cuts requiring extreme accuracy.
Plunge locks and depth stops give operators control over obtaining precise depth of cuts.
These are images -- below and to the right -- of my Stanley-Carter router-shaper. Anthony Blankley, biographer of Ray L Carter, thinks that this router shaper is a 1950s vintage, and not from the 1930s. He bases his claim on the "M 510A" above. "M" is likely Model, the model no "510" But the punched in later, by hand, is a mystery.
Sources: Herman Hjorth, "The Router: How to Operate Your Power Tools", Home Craftsman 18, no 6 November-December 1949, pages 17-23+ (Curiuosly, this same article -- both text and images -- is in a 1950 book published by HC, How to Operate Your Power Tools, this time allegedly authored by Milton Gunerman, listed as an Associate Editor of HC. (Hjorth died in 1951.) See also William Holtrop and Herman Hjorth, Modern Machine Woodworking, Milwaukee: The Bruce Publishing Company, 1960, pages 198-205. (Herman Hjorth in 1937.)
(Below is an exploded view of the famous "dome-topped" Carter-Stanley router, of 1929.)
Pin routers can shape, mold and rabbet the outside edges of workpiece, plunge-cut and/or groove and bore precisely for inlay, cut mortises, and create identical parts. Dennis R Wilson's article explains six ways to operate pin routers, which cutters are best, and safe use. Other information covers homemade overhead and pin routers.
The pin router can operate in six modes: Mode one, freehand, similar to using a portable router freehand, except that you move the stock rather than router, with the advantage that you can see view the operation. Mode two uses a straight fence for straight-line shaping. In mode three, you shape with the workpiece pressed against a pilot on the cutting tool. In modes four and five, either the workpiece is pressed against the guide pin, or the workpiece is set on top of a pattern or jig.
For mode six -- for internal shaping, scroll cutting and flat-relief carving -- the workpiece is fastened to a template whose underside has been routed out to follow the guide pin. Mode six is good for routing multiple recesses for Inlays.
Source: Dennis R. Wilson, "The Pin Router: Basic Setups for This Versatile Machine", Fine Woodworking No 29 July-August 1981, pages 63-65.
Sources: Herman Hjorth, Principles of Woodworking Milwaukee: The Bruce Publishing Company, 1930; Herman Hjorth Machine Woodworking Milwaukee: The Bruce Publishing Company, 1937; Herman Hjorth, “The Router”, Home Craftsman 18 1949, pages 56-57; Milton Gunerman, How to Operate Your Power ToolsNew York: Home Craftsman Publishing Corp., 1950; Dennis R. Wilson, "The Pin Router: Basic Setups for This Versatile Machine", Fine Woodworking No 29 July-August 1981; [Anonymous], "Elu Plunge", ShopNotes 1, no 1 January 1992, pages 10-11; Nick Engler, Routing and Shaping: Techniques for Better Woodworking. Emmaus, PA: Rodale Press, 1992; Albert Jackson and David Day Good Wood Routers Cincinnati: Betterway Books, 1996; Anthony Bailey, Routing for Beginners Lewes, East Sussex, England: Guild of Master Craftsman Publications, 1999; 2012; R J DeCristoforo, The Jigs and Fixtures Bible: Tips, Tricks and Techniques for Better Woodworking Cincinnati: Popular Woodworking Books, 2001(First published in PW, April 2000; Dennis R. Wilson, "The Pin Router"Fine Woodworking #29.
See also Shaper. A powered cutting tool, handheld or table mounted -- . See also Router Table -- with a cutter located on the end of the Shaft of a high speed Universal (25,000 RPM) Motor. Used for making Profiles,Pattern Cutting, Dovetails, etc.
Router bits are smaller than Shaper Cutters for good reasons.
The larger the diameter of the router bit, the greater the stress on the router's motor. Heed the advice of Nick Engler -- a noted authority on both shapers and routers -- : "Just because you can fit a 3 1/2-inch-diameter panel-raising bit in your 11/2-horsepower router doesn't mean you can use it. If the router isn't equipped to handle the load, the motor could heat up and bum out." Source: Nick Engler, Routing and Shaping: Techniques for Better Woodworking. Emmaus, PA: Rodale Press, 1992, page 2. this link is not working click on this link for discussion of Router Bits, Shaper Cutters and Jointer and Molding Knives.
[should go to Planes (Hand) entry] A double-handled holder for a small cutter used for surfacing the bottoms of grooves which are parallel with the top surface. Home Craftsman 4 1935 July-August page260)
Mounted on Spindle with Shaper Cutter, and allows shaping operations without protective Fence. used for shaping curved work such as Cathedral Doors as well as many custom shapes. They are also used for limiting the depth of cut (same principle as router bits with guide bearings). Use them below, in between or above cutters.
[Temporary Fix - I am adapting this entry from material located in the Sources: section directly below. While a Router and Shaper have similarities, I have never encountered the usage of these two tools in quite the manner below.
[from Hjorth, 1949 -- this is a fragment from a larger piece on the router and its uses, one of a series of seven or eight articles that Home Craftsman commissioned Hjorth to write in the later '40s.]
Shaping. With the use of the router molding bit shown in Fig. 7, the hand router can be used to cut moldings along the edge or end of stock as shown in Fig. 32. With the use of a special stand to hold the motor, the machine can be used for fluting or beading a turning as shown in Fig. 33. By installing the motor in a unit called a shaper plate, the router can be converted into a spindle shaper as shown in Fig. 34. Shaper cutters to make straight, con-cave or convex cuts are available in a variety of sizes. Corner, spindle and surface head cutters are also available. Fluting, chamfering and V-rabbeting cutters can also be obtained. These cutters can be used individually or in combination as shown in Fig. 35. pp 56-57 Image needed.]
Source: Herman Hjorth,"The Router", Home Craftsman 18 1949, pages 56-57.
[More on "router" This is a fragment from Campbell and Mager, for a woodworker's manual commissioned by Stanley Tools, and where Stanley Tools are featured exclusively]
Because of its motor rotates at a high-velocity -- 18,000 to 27,000 r.p.m. -- the router is designed by some manufacturers to be convertible for use as a bench shaper. The advantages of using the router in this manner, rather than as a portable tool, for cutting moldings and other shapes, is apparent if you consider awkward it is to clamping small workpieces to a bench and then attempt to move the router over them.
A shaper plate, which converts your router into a bench router, is first installed in a bench. When you plan to use your router to cut moldings, unscrew the router from its base and mount the router motor on the shaper plate underneath the bench. This permits tilting the motor 45 to 90 degrees.
The shaper cutter extends through a hole in the bench top. Work is fed into the cutter by pushing it along the shaper fence, which extends across the bench top on either side of the cutter. By using different shaper cutters and by tilting the router motor to various angles, an almost infinite variety of shapes can be produced. The shaper cutter is of high-speed steel with three shaped blades spaced 120 degrees apart around it in one integral piece. Some shaper cutter blades are Carbide-tipped for much greater resistance to wear. As with other cutting tools, it is important to keep a sharp edge on the shaper cutters. A silicon carbide Hone, especially shaped for router bits and shaper cutters, is available and is very useful for honing router bits and shaper cutters to keep them at peak cutting efficiency. It can be used on either High-Speed Steel or Carbide-Tipped tools.
One or more shaper cutters fit on the shaper arbor and are secured by means of a nut. This nut should be wrench-tightened. It turns counter to the rotation of the shaper arbor in order to prevent its being loosened by shocks and vibration. The shaper arbor, like the router bits, is held in the chuck of the router, which also should be wrench-tightened. Spacing collars of various thicknesses can be used to position the shaper cutter, or cutters of the shaper arbor. Several shaper arbors are provided by the manufacturers, those for use with shaper cutters having 5/16-inch or 1/4 -inch arbor holes, for use in 5/16-inch or 1/4 -inch chucks, the length of which permits the use of spacing collars. Many types of shaper cutters are provided, each type available in a wide range of dimensions. They find great usefulness in the quantity production of moldings by home builders, as well as in woodworking projects by the homeowner and craftsman.
Straight face cutters. The cutting edge is straight across on this one. It will cut a chamfer if tilted to an angle.
Convex cutters. Convex cutters cut a concave surface on the piece. They can be used to cut fluting in the surface of a piece, or to make a concave angle on the corner of a piece.
Surface bead cutters. These cut a bead into the surface or on the edge of a piece. Not used for joinery work but to add decorative touches to moldings.
Concave cutters. Concave cutters cut a convex surface the piece — in other words, round off corners.
When shaping a piece either against the fence or against a collar, the piece must be held flat against the table and against the fence or collar. A spring hold-down can be used to keep your fingers out of harm's way.
When the shaper is used as a jointer, the outfeed half of the fence supports the piece after it has been shaped. It should be adjusted so that it is out of line with the infeed half of the fence by a distance equal to the width of stock you wish to remove. In other words, to make a cut 1/4 inch deep, move the outfeed portion of the shaper fence back 1/4 inch. With shaper blades that do not remove the entire edge of the piece, the two sections of fence are in line with each other.
The fence is used only to shape straight edges. Curved and circular edges are shaped against a collar. The collar, on the shaper arbor, rides along the edge of the work and controls the depth of cut. A fulcrum pin can be used to position the work more exactly. Collars are available in various diameters.
Always feed the work on your shaper against the rotation of the cutter, and with the grain of the wood. When a cut across the end of a piece must be made, cut that first, then make the finishing cut with the grain of the wood. The easiest way to make a small-size molding is to shape the edge of a larger-size board, then rip off the molding with a saw. This can be repeated for as many moldings as you wish and is easier for quantity production of moldings as well as just one.
Special guides, or jigs, for shaping curved and circular pieces can be cut from plywood and clamped to the table. More positive control of the piece to be shaped can be gained if the jig has the same radius as the piece, though this need not be so. The jig can have a larger radius than the piece; it is especially important in this case to clamp the jig carefully to the table to obtain the correct depth of cut. V-shaped jig will accommodate circular pieces of many sizes.
Sources: Robert Campbell and N H Mager How to Work with Tools and Wood, Stanley, 1965 (Copyright 1952) pages 312-315; Herman Hjorth, “The Router”, Home Craftsman 18 1949, pages 56-57; Robert Campbell and N H Mager How to Work with Tools and Wood, Stanley, 1965 (Copyright 1952).