A history of the planing mill

The writer has no apology to offer for presenting to the public this work on the care and management of planing-mill machinery. The forty years or more during which he has been identified with it - for thirty of which he has been actively engaged in its manufacture exclusively - is considered sufficient.

In September, 1886, he went out of business as a practical manufacturer; yet he cannot say that he does not still take an interest in it. The familiar hum of the planing-mill is still pleasant to his ear, and brings up grateful recollections of the past, and reminds him of the many warm friends that he had, and still has, among woodworkers all over the country. During that long experience and intimate relation with some of the oldest planing-mill men, a number of whom have long since gone to their rest, he was enabled to obtain many of the incidents and facts given in the following pages. The long experience of the author in its manufacture, sale, and use forms the basis of those suggestions for the construction, care, and management of planing-mill machinery; and if they should be found of practical use to those less experienced, then this work, which is dedicated to all users of such machinery, will not have been written in vain.

That such may be the case, is the sincere wish of the author.

CARE REQUIRED IN THE CONSTRUCTION OF WOOD-WORKING TOOLS - BEST PROPORTION FOR THE CYLINDER - RELATIVE LENGTH AND SIZE OF JOURNALS  CAST-STEEL CYLINDERS - THE BEST PRACTICAL METHOD OF FITTING THEM UP, ETC.

There is no piece of machinery pertaining to the business of wood-working that requires more care in its construction than the planing and matching machine. The speed is so rapid with the principal working-parts that any little imperfection will soon manifest itself. A steam-engine, or almost any other slow-running machine, may have slight imperfections, which may not manifest themselves for months after they have been put in use; but let one of the journals of a planing-machine cylinder not be perfectly round or be slightly sprung or a pulley or cutter head not in perfect balance, and you will find it out in less than ten minutes after the machine is started.

Again, wood-working tools - especially the planing-machine - do not always go into the hands of experienced mechanics. An iron-turning lathe, planer, or upright drilling-machine, when put up in the machine shop, goes into the hands of a competent machinist - one who is not only competent to put it up and run it, but, in most cases, with the suitable tools and patterns for that purpose, able to construct it and put it together; and if there should happen to be a slight imperfection in the work which has escaped the notice of the workmen at the factory where it was fitted up, he will quickly discover the cause and correct it.

But not so with a large majority of the planing-machines that are sent out from the different manufactories. A few, it is true, go into the hands of men who thoroughly understand their business; and if a machine is properly put up and adjusted at the factory, there never will be any trouble in putting it in successful operation. But a large portion of the planers which are sent out from the different manufacturers go into the hands of inexperienced operators, who are not practical mechanics, and whose experience with machinery is very limited. And as a general rule the machine is belted up, and started just as it came from the factory; and if everything happens to be in perfect adjustment, and is level and out of wind, it may go off all right. But if there should be any little imperfection in the fitting or adjustment, it is not usually discovered until something begins to smoke, and then perhaps the difficulty, whatever it may be, is not remedied until the machine is seriously damaged.

The rapid motion of a planer is such that, in order to avoid vibration, it requires that the frame be not only solid, but well put together. And here is a point where the skill and judgment of the designer are brought into requisition. It is not always the case that the frame having the greatest number of pounds of metal is the strongest and most efficient in resisting vibrations. Frames are frequently met with, the plates of which may be an inch thick, surrounded by a flat moulding. Such frames, although they contain an abundance of metal, are not well calculated to resist lateral vibration; for it must be understood that, with a combined planer and matcher, the tendency for vibrating sidewise is as great as perpendicular. Therefore, if the same frame, instead of its plate being one inch thick, it were just one half of that thickness, and the other half were put into wide, heavy ribs, with the same quantity of metal, double the strength to resist vibrations would be obtained.

The double plate frame which has recently been adopted by many first-class firms, if properly proportioned, and the plates far enough apart to give sufficient depth, is probably one of the strongest frames that can be made from the same amount of metal. But to answer well the purpose designed, the space between the plates, for heavy machines, should not be less than two inches.

The plates in this style of frame may be quite thin, and yet very strong and substantial. Whatever style of frame may be adopted, it should be put together with planed joints; and the top, wherever any of the works are attached, should be planed square and straight and lengthwise, so that when it is set up and bolted together the top of both sides of the frame will be square and parallel with each other. Then the whole frame should be levelled up both crosswise and lengthwise before any of the other parts are attached; and when thus set up, it should never be moved or changed until the machine is completed. The bed-plate for the top cylinder should next be put on and bolted to the frame; and if it has been carefully and accurately planed, it should agree with the frame and be perfectly level both ways. The back shaft should then be fitted into its boxes by the same level, and squared from a line previously drawn through the bed and square with the frame. From these two points all other parts of the machine should be put up and squared and levelled.

The advantages of erecting a machine in this manner, and always working from these two points, are that if every part is thus put up with reference to these two points, when the machine is finished and shipped to its destination and set up, if carefully levelled from these two points, every other part of the machine will be true and out of wind. Frequent cases have occurred where machines have been set up without reference to these two points, but levelled anywhere on the frame, that have given a great deal of trouble by heating the roller-boxes, binding so as to cut and. get stuck fast, and many other troubles, before the real cause was discovered, and the manufacturer it often blamed for the ignorance of the operator; whereas, if proper instructions had been given, and those instructions carried out, the machine would have started off all right in the first instance.

In all modern machines the bearings are all much longer than formerly. The cylinder-boxes, instead of from four to six inches, are now made from ten to twelve inches long; and when bearings of that length are babbited and scraped down to a perfect fit and sufficient packing put between the box and cap, the caps may be screwed down tight, and yet the cylinder will be perfectly free to revolve. But just raise one foot of the frame sufficient to put a piece of thin pasteboard under it, and it will cause the cylinder-boxes to so bind that it will be impossible to turn it with the hand without loosening up the caps and adding more packing. And if the machine were run in that condition, it will be found that the shaft does not bear upon the whole surface of the box, but only upon a small portion of it; and the consequence is, it will heat, and continue to heat, until it wears down again to a perfect bearing.

This accounts for the tendency of all new machines to heat when first started. It is almost impossible to place the machine exactly in the same position that it was when first set up in the shop; but if especial care is manifested in levelling across the bed-plate and through the boxes of the back shaft, that point may be found so near that a machine will frequently start up without any inconvenience from heating.