Popular Woodworking 2005-11 № 151, страница 48
moreover, to feel the difference, I suggest that you cut some strips of wood about Vs" thick by V2" wide by 10" long. Pine, maple, cherry or walnut will work fine, or you can use Popsicle sticks as shown.
Take a round-point awl and, about V2" from the end of the stick, press and twist the awl
through the wood. Inevitably the awl will split the wood along the grain. It will do this in almost all wood types.
Now try the same with a screwdriver-shaped brad awl. The wood will usually split, though not quite so quickly or automatically as with the round-point awl, provided you
ALL ABOUT ERGONOMICS
With its wide, oval-shaped bulbous handle designed to resist slippage and to fit up against the heel of the palm, my favorite brad awl was ergonomic long before anyone ever heard the word.
Comfort, fashioned by a man's hand, had little to do with the kind of economy that concerns us today. It was more a sense of commonplace frugality and carefulness because the very tools a man worked with were intrinsic to his life as a craftsman. Tools handed down through centuries of work still serve as perfect examples of true craftsmanship because the qualities of the man were reflected in the tools he made and were passed on to those of us who follow. The tool shown here tells its own story.
The awl is old and English in origin. Economy was of little consequence to its maker, except that he respected time and so used the best materials at hand. The heavy-gauge brass ferrule he used was a scrap found and saved as treasure in the till of his tool chest. The steel awl gently tapers up to the bolster that intersects the square, hammer-drawn tang. The brass-securing pin barely protruding through the shoulders of the handle prevents the tang of the awl bit from twisting in the handle.
But above all, don't overlook the oval-shaped, English ash handle. It never twists or slips under torque. When all the raw components were shaped into a tool to fit his own hand - one that would serve him for six decades or more - this tool meant more to him than gold. His heir would one day find the same tool to treasure with his own scraps from which a replica would soon allow the original to rest in its corner of the tool chest as this one did. - PS
begin penetrating the fibers with the screwdriver point initially placed across the grain as shown in the illustration at right, and then pushing and twisting the awl as it penetrates the fibers.
This twisting technique accompanied an intentional design feature of the tool. The problem was that nobody passed on the technique with the tool. The idea is that the cross-grain positioning of the flat blade acts something like a chisel to first cut the fibers and prepare for deeper penetration with subsequent pressure as you twist and push deeper through the fibers.
Now take a square-point birdcage awl and use the standard technique of twist and push continuously but carefully as you continue through the Popsicle stick. You should have a perfectly round hole all the way through to the
diameter of the corner-to-corner measurement of the awl.
Notice how the birdcage awl acts more like a reamer with the sharp, angular corners of the awl cutting the wood fibers instead of parting them and splitting the wood. Because round-point awls have no way of cutting the fibers, they instead serve only to compress, force and bruise the wood. The round point only parts the fibers and this inevitably causes the fibers to split.
In some situations, compression isn't bad. Sometimes it's good to leave all the fibers in place, such as in a large door stile or door frame where there is enough mass surrounding the hole to support the pressure given by the awl.
But for more delicate situations, such as near the ends of wood pieces, the birdcage awl finds its true value as a crafts-
Heavy brass ferrule encases the wooden shoulder around the tang and also reduces the possibility of splitting the wood at this critical point of leverage
Extra heavy bolster prevents tang of bit from penetrating deeper into handle under pressure
Oval-shaped handle fits comfortably and gives a firm grip
Brass pin passes through wooden handle at the shoulder and through the tang of the bit to prevent bit from turning under pressure
Shown here is the anatomy of a well-designed awl.
From left to right: birdcage awl, round-point awl and brad awl.
Press and twist different types of awls into the ends of Popsicle sticks and you can easily see the different ways different types of awls pierce wood.
Popular Woodworking November 2005