This section is from the "Modern Machine Shop Construction, Equipment, And Management" book, by Oscar E. Perrigo. Also see Amazon: Modern Machine Shop Construction, Equipment, And Management.
In selecting lumber for patterns care should be taken to get that which has been properly cut from the log, that is, lumber in which the edge of the grain shows on the side of the board. Otherwise it will be very liable to warp, no matter how much care has been taken to dry it, or to keep it well protected.
This will be better understood by referring to the engravings. Fig. 201 shows a cross-section of a board cut from the log in a proper manner. Fig. 202 shows the result of cutting the board from near the surface of the log, making what is technically known as a "siding." The dotted lines show how it will warp. This is due to the fact that the sap, or outer portion of the log, which is of newer growth, is less dense, and will contract more in the process of seasoning.
It is usual to cut up logs in the manner shown in Fig. 203. The boards taken off near the surface of the log are trimmed with an edging saw and should be sold as sidings, for inferior work, but never used as good pattern lumber, unless in a place where they are held and confined so firmly that they cannot warp or distort the pattern. For use as pattern lumber, or for any really good work, the log should be cut up as shown in Fig. 204, which preserves the grain in a proper direction as nearly as possible, but is not as economical as to the value of the lumber, as it makes a number of quite narrow boards. The furniture manufacturers' term of "quartered oak" refers to a log cut up as shown in Fig. 205, which is the most nearly correct so far as getting all the good lumber possible out of the log.
Fig. 201. The Right Way to cut a Board.
Fig. 202. The Wrong Way to cut a Board.
Fig. 203. The Usual Way of cutting up a Log.
Fig. 204. The Proper Way of cutting up a Log.
Fig. 205. Quartering the Log.
Pattern lumber is nearly always expensive, no matter where it may be purchased, and much more care should be used in cutting it up in the shop than is usually the case. If this matter is properly considered and thoroughly understood, very little need be wasted. It is well to have a series of shelves, placed conveniently to the circular saws, upon which such scraps as are likely to be useful may be arranged according to their size or shape, so as to be convenient to find when small pieces are wanted.
When a board or plank is cut and a considerable portion of it is left it is customary to stand it up against the wall, or in some convenient corner. This is repeated until a quantity accumulates, the lower ends of the pieces projecting further and further out from the wall, occupying more and more of the floor space, continually "kicked and cussed" until the nuisance becomes unbearable and a cleaning-up process usually results in throwing a good many pieces into the scrap pile.
This might easily be avoided by making a rack, consisting of a piece of 3×4 inch scantling, in which are fixed hard wood pins one inch in diameter, placed about six inches apart, and projecting about a foot. This scantling is spiked to the wall in a horizontal position, three to four feet from the floor, with the pins projecting outwardly from it. Pieces of lumber four to eight feet long may be conveniently set up on end between the pins, and any piece wanted may be readily removed without disturbing any of the other pieces. The length of this rack will, of course, depend upon the available space that can be spared for it. One near the circular saws, in addition to the scrap shelves described above, will be found very useful.
One of the best methods of working up the accumulation of small scraps is to have an apprentice make them up into core prints and bosses of all the various sizes in common use, keeping the different sizes in suitable boxes or bins built against the wall. This will not only use up the scraps but will save a good deal of the time of the pattern makers, whose time is too valuable to be spent at this common work.
Another point needs attention in most shops, and that is the too frequent disposition to use first-class lumber for such parts of a pattern as cleats, stop-off pieces, core box backs, the inside framing of a boxed-in pattern, etc., when lumber at half the price would be just as good and cost no more to work up. A considerable saving in lumber bills may be made by attention to these matters, and the standard of good work not lowered for any practical purpose.
Fillets and dowel pins can be much cheaper purchased than made in the shop. A good deal of discussion as to the relative merits of wood and leather fillets has been indulged in. The pattern maker's time will no doubt be saved, and good pattern work be the result of using wood fillets for straight work and leather fillets for curves.
The patented brass dowel pins should be put into all patterns that are to be in continuous use, and the malleable iron rapping and lifting plates, let into the pattern, should be used on all patterns large enough to need them. A stock of these convenient and very necessary articles should always be kept on hand and ready for use.
The system of marking and listing patterns is usually arranged in the drafting room, and the lists furnished to the pattern shop for use and guidance. The plan recommended is to designate each machine built, by a letter of the alphabet, or a combination of two of them, and to indicate the individual patterns of each machine by numbers.