THE THRESHING MACHINE.

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Of the Frick Company, Waynesboro, Pa.

The first few years of the introduction of the wind stacker, the waste of grain was shown at every opportunity, presented by those that did not yet have the wind stacker. This waste of grain was all charged to the wind stacker. So great was the 'howl' against it that it was predicted by many that it would never come to the front as a standard method for handling straw. The writer, however, took the position at the start that there was never a wind stacker attached to a threshing machine responsible for the waste of a single kernel of any kind. On account of his former struggles with the thresher cylinder and his rigid demands for clean threshing, and his knowledge of the imperfect work the threshing cylinders were doing, led him to expect trouble from the use of the wind stacker before he attached it, and from the start that position was taken, as far as the writer believed it policy, for the best interests of his employers. The situation was a peculiar one. If the cause of the waste of grain with the straw would have been placed always where it belonged - unclean threshing-then the chances were that the customer or thresherman would not accept the threshing machine, even if the wind stacker would be exchanged for the net; but as long as it was believed that the wind stacker was alone responsible, the dissatisfaction of the farmer and thresherman could generally be easily adjusted by simply again attaching the net stacker, as in most cases the wind stacker was the choice of the thresherman when giving his order. Under these circumstances there was some danger of misrepresentation, in cases where the agent had not encouraged the purchase of the wind stacker. This condition of affairs drove the writer to further investigate the cause of unclean threshing, remembering that when a boy working on a farm and often helping to thresh with the old style thresher, the cylinder being a solid drum of wood covered with sheet iron and short teeth driven into the wood, he could not recall of ever hearing any complaint of not threshing clean, but in later years often heard farmers speak of that machine not threshing clean and that the straw stacks would get green.

This complaint about bad threshing and green straw stacks has its start with the introduction of the bar, or open cylinders, the first having but six bars, leaving a wide gap, or space, between them. The use of this form of cylinder proved very unsatisfactory, and was set aside by one composed of nine bars, and was, at the time, claimed a great improvement over the six bar. Later the twelve-bar was introduced and was soon O.K.'d by all, and is the standard today. The writer's observations are that at a moderate rate and regular feeding, with the grain in good condition for threshing, the 12-bar cylinder is all that could be desired; but in this age of steam versus horse power and the great demand for rapid threshing (which is brought about by the immense crops and short seasons) and the very bad conditions of grain in some seasons, the writer is convinced that another step will be demanded and that an open, or bar, cylinder cannot be constructed within the present room for the width of concave bed that will meet the present requirements-fast threshing-short of a closed cylinder. To further explain on this point, we will say, providing the present sized cylinders, which vary from 15 to 18 inches, would admit of sufficient width of concave so that the front concave tooth could be a sufficient distance from the rear tooth, so that all the heads of grain that are taken by the bars in place of the teeth, when crowding the thresher, would have time to be thrown out from between the bars and into the rear concave teeth, thereby making sure that all heads of grain come in contact with the concave teeth; so long as this does not occur, just so long there will be heads passing the threshing device un threshed.

We might further give as a reason for faith in us by calling your attention to machines designed for threshing beans and peas. Those having experience with bean threshing know that it requires a much slower speed of the cylinder to prevent the breaking of the bean, and it also requires a very long concave bed so that the teeth from the first to the last in the concave will cover as much of the cylinder surface as possible; but even with the wide concave, the experience of those building such machines evidently suggested and led them to adopt a second threshing cylinder to complete the threshing of beans. This is what an open, or bar, cylinder no doubt requires. Beans or peas are fed into the cylinder in a loose and tangled shape, and many of the pods fly into the cylinder between the bars and pass through without any interruption by the concave teeth. They are, of course, all taken from the vines after passing the first cylinder, and will, while being shaken from the first to the second cylinder, be in much better order to make the threshing complete, as the unbroken pods will settle to the bottom and the vines remain on top, so that the second cylinder will force all the pods through its concave teeth.

The writer some years ago made a series of experiments with large cylinders, and as there is at present a tendency for some manufacturers to advocate and build a much larger threshing cylinder, he thought it not out of place to give some of his conclusions on this point. His experiments with cylinders from 18-inch to 60-inch, or 5 feet diameter, determined that an 18-inch cylinder with the same width of concave is decidedly a cleaner thresher than one 60 inches in diameter. There is, however, one feature in the large cylinder which would, to a casual observer, appear to be an advantage. He would likely notice that it would admit of a greater irregularity of feeding without any apparent effect on the speed. This would, of course, retain a greater uniformity of speed of all the other parts of the machine, which in itself would cause the machine to give better satisfaction. But the fact is, the increased size of the cylinder has nothing whatever to do with the improvement in the performance of the machine, but it is its increased weight. We must not lose sight of the fact that in the same proportion that the cylinder is enlarged we also increase its weight, and if we would increase the weight of the small cylinder to that which the size of the large one demands, then there could not possibly be any improvement or difference, as the speed of the teeth in both cases are the same, and there is no reason seen by the writer why there should be a difference. It would be pound for pound and speed for speed, and so far as our subject relates to these two factors in the problem, there could be no difference; but on account of the much greater per cent of the weight of the large cylinder acting on the straw at any one time, and the pull, or resistance, to each tooth being practically the same, it occurs to the writer that if the cylinders were both of the same weight and the speed of the teeth also the same (which they are), that it would take a less amount of straw to affect the speed of the large cylinder than it would that of the small one. But when we come to the clean threshing question, it will be found by tests that when conditions for conditions are taken with the large and small cylinders, both threshing a certain quantity, and then rethresh the straw from the large cylinder with the small one, you will find you will have more grain than if you thresh the straw from the small cylinder with the large one. One of the causes of this difference is that when the large cylinder is crowded to the capacity of the space between the cylinder bars and the concaves, there is much more chance for the heads to enter between the bars of the large -cylinder than there would be on the small one, as the curve or circle is much shorter and fewer openings or spaces between the bars exposed to the straw on the small cylinder; and, as the speed of the periphery or teeth of the small and large cylinders are the same, the centrifugal force must also be the same, which is all that compels the straw to leave the cylinder teeth and pass through the space occupied by the concave teeth only, and as the curve of the large cylinder presents a greater surface to the straw while it is being threshed, there is, to some extent, more chances for heads to be carried between the bars while they are passing over the concave than would be with the small cylinder. The writer, however, is not in position to say that a large cylinder might not admit of a sufficiently wider concave bed, and on that and only that account be of some little advantage, but if such increased width of concave is not sufficiently greater so it will increase the time of the cylinder teeth passing the concave bed, then he, up to this time, has been unable to see any advantage in a large cylinder, but some disadvantage; such as, in case of accidents, say a wrench, chain, bolt, fork or horseshoe fed into a large cylinder, there would certainly be more to wreck than on a small cylinder, and the damage and expense much greater.

We, however, are always open for the best; and when it is proven that a large cylinder has advantages over that of the present size, we shall advocate it as strongly as any one, and know the reason why.

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