Radial arm saw

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Radial Arm Saw Radial arm saw osha.jpg
Radial Arm Saw

A radial arm saw is a cutting machine consisting of a circular saw mounted on a sliding horizontal arm. Invented by Raymond DeWalt in 1922, the radial arm saw was the primary tool used for cutting long pieces of stock to length until the introduction of the power miter saw in the 1970s.

Contents

In addition to making length cuts, a radial arm saw may be configured with a dado blade to create cuts for dado, rabbet or half lap joints. In addition some radial arm saws allow the blade to be turned parallel to the back fence, allowing a rip cut to be performed.

Origins

Unlike most types of woodworking machinery, the radial arm saw has a clear genesis: it was invented by Raymond DeWalt of Leola, Pennsylvania. DeWalt applied for patents in 1923, which were issued in 1925 (US Patent 1,528,536). [1] DeWalt and others subsequently patented many variations on the original, but DeWalt's original design (sold under the moniker Wonder Worker) [2] remained the most successful: a circular saw blade directly driven by an electric motor held in a yoke sliding along a horizontal arm that is some distance above a horizontal table surface. A saw which combines the sliding and compound features is known as a sliding compound miter saw or SCMS.

Before the advent of the radial arm saw, table saws and hand saws were most commonly used for crosscutting lumber. Table saws can easily rip stock, but it is awkward to push a long piece of stock widthwise through a table saw blade. In contrast, when a radial arm saw is used for crosscutting, the stock remains stationary on the saw's table, and the blade is pulled through it.

During the late 1970s, the compound miter saw began to replace the radial arm saw, [3] but only for crosscuts and miter cuts since miter saws are unable to perform rip cuts. The radial arm saw can be less safe when used by an inexperienced or untrained operator, but is not as dangerous when used properly. In the hands of an experienced operator, the radial arm saw can safely cut compound miters necessary for picture and door frames, rip lumber precisely to width, cut tongues and grooves, and make variable dadoes. Like the compound miter saw, the radial arm saw can make these cuts with absolute precision, but is capable of making a wider variety of cuts, including more complex ones.

In the home shop the radial arm saw is an alternative to the table saw. Both machines can rip, crosscut, do simple and compound miters, dado, mold or shape, make tenons, make open mortises, taper cut, and rabbet. The radial arm saw requires less clearance or space in the shop to handle long stock, since it only requires clearance on the sides, whereas a table saw needs clearance to the sides, in front and at the back. The radial saw is perfectly effective backed up against a wall, whereas the table saw needs to be placed in the center of the shop to give all around clearance. With some accessories the former can be used as a shaper, a disk or drum sander, a grinder, a surface planer, a router, a horizontal boring machine and even as a power unit for a lathe; whereas a table saw's secondary uses are limited to shaper and disk sander. The major shortcoming of most current radial arm saws for home-use is that, most radial arm saws that have been built after the early 1960s are manufactured with stamped sheet metal parts and are machined to loose tolerances, hence they are not precise for doing accurate work without 'tuning'. A high-quality radial arm saw has carefully machined track arm ways and locking mechanisms, and a motor that runs very smoothly; under 'no-load' conditions most of the sound and vibration will originate from the whisper/whistling and the imbalance of the saw blade upon the arbor.

The saw tilts on all axes except vertical slope – see photo (all points of rotation are not clear in photo).

If machining depth cuts, the radial arm saw allows one to see the progress. With the (wood) clamped and using the arm (not hand feeding, which is also possible), the cuts are better machined and require no jig setup; the advantage is not widely needed however. Cutting full depth is less convenient, as the saw lowers into the table, cutting the table (often a wood table for that reason).

"Top cutting" machined saw table with differing axis designs are still made and sold.

Safety

Power saws can easily cut off fingers. Furthermore, a dull blade will grab lumber with enough force to kick it through a wall. A new blade has less tendency to grab but still requires proper feeding.

Radial arm saws are safer with a blade with a very low or negative hook angle[ citation needed ], to inhibit overly fast feed rate, binding, and the blade's tendency to try to "climb" the material. Also, a 10 degree positive hook blade with a "triple chip profile" works well on the radial arm saw and can be considered a universal blade. If the saw climbs with this blade, the yoke roller bearings need to be adjusted and tightened.

Occupational Safety and Health Association (OSHA) Requirements in the United States

According to OSHA regulation 1910.213(h)(1): The upper hood shall completely enclose the upper portion of the blade down to a point that will include the end of the saw arbor. The upper hood shall be constructed in such a manner and of such material that it will protect the operator from flying splinters, broken saw teeth, etc., and will deflect sawdust away from the operator. The sides of the lower exposed portion of the blade shall be guarded to the full diameter of the blade by a device that will automatically adjust itself to the thickness of the stock and remain in contact with stock being cut to give maximum protection possible for the operation being performed. [4]

Demise

By the early 2000s, the radial arm saw was well into its demise. In a 7-July-2010 article [5] "Is the Radial Arm Saw on its Last Legs?," Tom McKenna, Managing Editor of Fine Woodworking, opined that it was, for these reasons:

The demise of the radial arm saw can be observed in the products for sale by tool retailers. As of May, 2014, Sears showed only one radial arm saw in its online catalog, [6] Amazon listed only two (one of which was the Sears model), and Grizzly, Jet, and Tool Zone listed none. As of May, 2018: on the Craftsman website, the Sears Craftsman 10 inch radial arm saw is listed as "no longer available," [7] and Amazon only lists one 10 inch model. [8]

Industrial sized radial arm saws (with blade diameters of 305 to 560 mm [12 to 22 inches]) are still manufactured in the United States by the Original Saw Company in Britt, Iowa — having purchased the rights to "The Original" radial arm saw from DeWalt. [9] It seems the home/small-shop 250 mm (10 in) radial arm saw, though, has seen its demise after being manufactured for just over 95 years.

Related Research Articles

Woodworking Process of making objects from wood

Woodworking is the skill of making items from wood, and includes cabinet making, wood carving, joinery, carpentry, and woodturning.

Router (woodworking)

The router is a power tool with a flat base and a rotating blade extending past the base. The spindle may be driven by an electric motor or by a pneumatic motor. It routs an area in hard material, such as wood or plastic. Routers are used most often in woodworking, especially cabinetry. They may be handheld or affixed to router tables. Some woodworkers consider the router one of the most versatile power tools.

Circular saw Power tool

A circular saw is a power-saw using a toothed or abrasive disc or blade to cut different materials using a rotary motion spinning around an arbor. A hole saw and ring saw also use a rotary motion but are different from a circular saw. Circular saws may also be loosely used for the blade itself. Circular saws were invented in the late 18th century and were in common use in sawmills in the United States by the middle of the 19th century.

A saw is a tool consisting of a tough blade, wire, or chain with a hard toothed edge. It is used to cut through material, very often wood, though sometimes metal or stone. The cut is made by placing the toothed edge against the material and moving it forcefully forth and less vigorously back or continuously forward. This force may be applied by hand, or powered by steam, water, electricity or other power source. An abrasive saw has a powered circular blade designed to cut through metal or ceramic.

Table saw Woodworking tool

A table saw is a woodworking tool, consisting of a circular saw blade, mounted on an arbor, that is driven by an electric motor. The blade protrudes through the top of a table, which provides support for the material, usually wood, being cut.

Rip cut

In woodworking, a rip-cut is a type of cut that severs or divides a piece of wood parallel to the grain. The other typical type of cut is a cross-cut, a cut perpendicular to the grain. Unlike cross-cutting, which shears the wood fibers, a rip saw works more like a series of chisels, lifting off small splinters of wood. The nature of the wood grain requires the shape of the saw teeth to be different thus the need for both rip saws and crosscut saws; however some circular saw blades are combination blades and can make both types of cuts. A rip cut is the fundamental type of cut made at a sawmill.

Plane (tool) Tool for working with wood

A hand plane is a tool for shaping wood using muscle power to force the cutting blade over the wood surface. Some rotary power planers are motorized power tools used for the same types of larger tasks, but are unsuitable for fine-scale planing, where a miniature hand plane is used.

Japanese saw Cutting tool

The Japanese saw or nokogiri (鋸) is a type of saw used in woodworking and Japanese carpentry that cuts on the pull stroke, unlike most European saws that cut on the push stroke. Japanese saws are the best known pull saws, but they are also used in China, Iran, Iraq, Korea, Nepal and Turkey. Among European saws, both coping saws for woodworking and jeweler's saws for metal working also cut on the pull stroke like Japanese saws. Cutting on the pull stroke is claimed to cut more efficiently and leave a narrower cut width. On the other hand, a pull stroke does not easily permit putting one's body weight behind a stroke. This can be readily solved by using a vice or clamping. Another disadvantage, due to the arrangement and form of the teeth, is that Japanese saws do not work as well on hardwoods as European saws do. Japanese saws were originally intended for comparatively soft woods like cypress and pine whereas European saws were intended for hard woods like oak and maple.

Panel saw

A panel saw is any type of sawing machine that cuts sheets into sized parts.

Bandsaw Power saw with a long, sharp blade

A bandsaw is a power saw with a long, sharp blade consisting of a continuous band of toothed metal stretched between two or more wheels to cut material. They are used principally in woodworking, metalworking, and lumbering, but may cut a variety of materials. Advantages include uniform cutting action as a result of an evenly distributed tooth load, and the ability to cut irregular or curved shapes like a jigsaw. The minimum radius of a curve is determined by the width of the band and its kerf. Most bandsaws have two wheels rotating in the same plane, one of which is powered, although some may have three or four to distribute the load. The blade itself can come in a variety of sizes and tooth pitches, which enables the machine to be highly versatile and able to cut a wide variety of materials including wood, metal and plastic.

Crosscut saw

A crosscut saw is any saw designed for cutting wood perpendicular to (across) the wood grain. Crosscut saws may be small or large, with small teeth close together for fine work like woodworking or large for coarse work like log bucking, and can be a hand tool or power tool.

Miter saw Mechanical saw used to obtain precise angle cuts

A miter saw or mitre saw is a saw used to make accurate crosscuts and miters in a workpiece by positioning a mounted blade onto a board. A miter saw in its earliest form was composed of a back saw in a miter box, but in modern implementation consists of a powered circular saw that can be positioned at a variety of angles and lowered onto a board positioned against a backstop called the fence.

Wood shaper

A wood shaper, usually just shaper in North America or spindle moulder in the UK and Europe, is a stationary woodworking machine in which a vertically oriented spindle drives cutter heads to mill profiles on wood stock. The wood being fed into a moulder is commonly referred to as either stock or blanks. The spindle may be raised and lowered relative to the shaper's table, and rotates between 3,000 and 10,000 rpm, with stock running along a vertical fence.

Bucksaw Hand-powered frame saw

A bucksaw is a hand-powered frame saw similar to bow saw and generally used with a sawbuck to cut logs or firewood to length (bucking). Modern bucksaws usually have a metal frame and a removable blade with coarse teeth held in tension by the frame. Lightweight portable or foldable models used for camping or back-packing are also available. It is often referred to as a bow saw in the North American hardware market, but that term traditionally refers to a different type of saw with a wooden frame.

A combination machine is a woodworking machine that combines the functions of two or more separate machines into a single unit. For example, a combination machine might consist of a tablesaw with a side-mounted jointer. Another common example of this type of machine is the jointer-thicknesser which combines the function of a jointer with that of a planer.

Dado set

A dado set or dado blade is a type of circular saw blade, usually used with a table saw or radial arm saw, which is used to cut dadoes or grooves in woodworking. There are two common kinds of dado sets, stacked dado set and wobble blade.

Stop block

A stop block is a simple reusable jig used in metalworking and woodworking to locate a common edge of a workpiece so that multiple workpieces can get the same operation performed quickly. Common applications are table saws and manual milling machines, but they are also used on miter saws, band saws, radial arm saws, and abrasive saws.

This glossary of woodworking lists a number of specialized terms and concepts used in woodworking, carpentry, and related disciplines.

Riving knife Safety device installed on woodworking saws

A riving knife is a safety device installed on a table saw, circular saw, or radial arm saw used for woodworking. Attached to the saw's arbor, it is fixed relative to the blade and moves with it as blade depth is adjusted.

Fence (woodworking)

A fence is a part of many woodworking tools, they are typically used to guide or secure a workpiece while it is being sawn, planed, routed or marked. Fences play an important role for both accuracy and safety. Fences are usually straight and vertical, and made from metal, wood or plastic.

References

  1. http://www.patentplaques.com/blog/?p=2352 accessed 10-Feb-2014
  2. Loose, John Ward Willson. The heritage of Lancaster. Woodland Hills, Calif.: Windsor Publications, 1978. 188. Print.
  3. "Compound Miter Saw". Heartwood Farms. 2013.
  4. "1910.213 - Woodworking machinery requirements. | Occupational Safety and Health Administration". www.osha.gov. Retrieved 2019-11-08.
  5. http://www.finewoodworking.com/item/29415/is-the-radial-arm-saw-on-its-last-legs accessed 2-May-2014
  6. http://www.sears.com/tools-bench-stationary-power-tools-radial-arm-saws-accessories/b-1021237 accessed 2-May-2014
  7. "Craftsman Professional 3 hp 10" Radial Arm Saw with LaserTrac ™ 22010". www.craftsman.com. Archived from the original on 2016-06-18.
  8. https://www.amazon.com/dp/B01LZ42R0Y/ref=olp_product_details?_encoding=UTF8&me=
  9. "Our Company".