26F 



HARDWOOD RECORD 



of a log mill and left entirely unmolested. 



Any thickness may be sawn oflE the lower 

 side of a slab or plank at wOl by use of 

 set works (patent applied for), which ele- 

 vates that portion only of the saw which 

 does the cutting. The change from one 

 thickness to another is made in an' instant, 

 and crowding wheels serve the purpose both 

 of setting the saw for different thicknesses 

 and of saw guides. 



Another important feature is the strain- 

 ing device for the saw blade, which is as 

 sensitive as that on any vertical band mill; 

 all sliding surfaces, or rack and pinion con- 

 struction in connection with the saw strain- 

 ing mechanism, are avoided, and nothing 

 employed which wOl become in the least 

 inoperative, because of sawdust, pitch or 

 other refuse. The variable friction feed is 

 most powerful and convenient. 



The upper press rolls are of large diam- 

 eter, and are constructed in sections, each 

 of which will swing to any desired height, 

 independent of the others. Each of these 

 sections is supplied with an air cushion, 

 which does away with all shock, due to the 



dropping of the rolls after a heavy butt 

 slab or cant has been fed through the ma- 

 chine. 



The web-wheel or driving band wheel is 

 supported in journal boxes that are self- 

 adjusting, self-lubricating, and so con- 

 structed as to secure perfect alignment at 

 all times; the wheel corresponding to the 

 upper wheel on a vertical mill is of the 

 latest and most approved type; it is pro- 

 vided with a weldless steel rim accurately 

 ground to templet, and is equipped with 

 convenient cross-line adjusting device. Pat- 

 ented self-feeding oil pockets and scrapers 

 are used for keeping the face of the wheels 

 and the saws free from gum and pitch. 



All long trains of gears or chains are 

 avoided, each feed roll licing driven as di- 

 rectly from the main driving shaft as prac- 

 ticable. 



Dimensions: Wheels, 66 inches in diam- 

 eter, mounted on extra heavy hammered 

 crucible steel arbors; driving pulley, 28 

 inches in diameter, 12^4-inch face, should 

 make 500 r. p. m.; saws, 8 inches x 35 feet 

 C inches long; weight, 16,Ono pounds. 



Suggestions to Small SaWmill J\len. 



THIBD 



A number of questions have come to the 

 writer on subjects of sufficient general in- 

 terest to be entitled to discussion here as 

 the answers may contain suggestions of 

 value to many operators of small sawmills. 

 The first one relates to portable mills and is 

 as follows: 



"I am operating a small portable mill 

 with a butterfly-valve on the engine in- 

 stead of a governor, and the engine being 

 mounted on the boiler shakes it consider- 

 ably, so much so that I am anxious to know 

 how to stop it. What is the best way to 

 fasten the boUer down to prevent shaking, 

 or is it best to take the engine off and bed 

 it separately? Would it improve the mat- 

 ter any should I replace the butterfly-valve 

 with a governor?" 



There is no question but that the best 

 way to prevent the engine from shaking the 

 boiler is to dismount it and bed it sepa- 

 rately. There are, however, other questions 

 that enter here besides that of preventing 

 shaking. Since the mill is a portable one 

 naturally it is desired to preserve its port- 

 able qualities and keep the machinery in 

 such shape that it can be moved and set up 

 with the least possible labor and expense. 

 The chief recommendation of the portable 

 mill is the fact that it can be moved with 

 small expense to the seat of the log supply 

 instead of hauling the logs great distances 

 to the mill. If the boiler is mounted on 

 skids and of rather a heavy type, with the 

 engine mounted on top in a self-contained 

 frame, it is just about as convenient for 

 moving to have it on a separate bed, be- 

 cause it lightens the task of loading and 

 hauling as it can be divided in two parts. 

 If of lighter type, however, mounted on 



PAPER. 



wheels so that the boiler and engine can be 

 readily hauled about, it is not generally 

 advisable to dismount the engine. 



Fastening down the boiler so as to hold 

 it rigid is not advisable. It may be Scotch- 

 braced a little here and there, but if the 

 boiler is fastened rigidly while the engine 

 has a tendency to shake it, the chances are 

 that the boiler will be seriously injured by 

 working loose in the joints. Instances 

 are known where efforts of this kind have 

 resulted in working the flues loose in a 

 boiler at such a rate as to render it prac- 

 tically useless for power purposes. By 

 fastening the boiler the tendency to shake 

 is not overcome, and when the boiler cannot 

 give and shako a little as a whole to humor 

 this tendency, the strain is simply removed 

 from the body of the boiler to its integral 

 parts and then it becomes a more serious 

 trouble than if it were permitted to shake 

 and rock a little on its skids or wheels. It 

 should not be inferred from this that shak- 

 ing is good for the boiler, lor it is not, but 

 fastening it down rigidly rather increases 

 than lessens the annoyance. What should 

 be done is to find out the causes of the 

 shaking and remedy them. 



There is a certain amount of vibration in 

 the operation of any ordinary engine, in- 

 duced by the intermittent reversing of the 

 strain, yet shaking of a serious or trouble- 

 some nature is generally due to a lack of 

 running balance. To remedy this trouble, 

 then, the first thing to look to is the en- 

 gine's balance. By a little experimenting, 

 turning the engine over empty, it may be 

 determined whether or not it is seriously 

 out of balance, but if it is a high speed en- 

 gine with a fly-wheel of small diameter, the 



task will be a somewhat tedious one, be- 

 cause when the engine is disconnected, to 

 have the crank shaft and fly-wheel free for 

 experiment, the weight of the connecting 

 rod is taken ofl". It is possible by the use 

 of a balance or some portable weighing ap- 

 paratus to get at the weight of the crank 

 end of this connecting rod and its braces 

 while the other end continues to swing in 

 the cross head, and then by attaching to the 

 crank pin an equal weight a reasonably ac- 

 curate running balance with the engine 

 disconnected may be had. The detail, how- 

 ever, depends considerably on local condi- 

 tions and personal ingenuity; the main 

 point is to make sure by some means that 

 the engine is in proper balance, and if it is 

 not put it in balance, when it will probably 

 be discovered that the cause of the shaking 

 has been removed. 



As to the butterfly-valve and the gov- 

 ernor, it is generally more satisfactory all 

 around to have a good governor on the en- 

 gine, but still, there are instances where it 

 is really not advisable. Where the steam- 

 ing capacity of a boiler is severely taxed 

 to keep the mill going there is quite an ar- 

 gument in favor of the butterfly-valve, be- 

 cause when the saw is not in the cut steam 

 can be shut off so close that there is barely 

 enough passing through to keep the machin- 

 ery moving, thus giving the boiler a better 

 chance to accumulate against the strenuous 

 need of the next cut than is afforded by the 

 average governor, which presumably keeps 

 the machinery moving at the same speed all 

 the time. On the other hand, a reckless 

 sawyer at times will open the butterfly- 

 valve and permit the mill to attain an en- 

 tirely unreasonable speed. This not only 

 leads to excessive vibration and shaking on 

 the part of the engine, but is a hard strain 

 on the machinery generally, which in time 

 will wreck it. Moreover, even the most 

 conservative of sawyers permit this over- 

 speeding frequently enough to raise an ob- 

 jection to the butterfly-valve. There is a 

 way to get around this, and probably the 

 best equipment where economy in steam by 

 the close cut-off of the butterfly-valve is 

 desired is to have both a butterfly-valve and 

 a governor. Put the butterfly in front of 

 the governor so that steam can be shut off 

 close when the saw is not in the cut, then 

 when the sawyer pulls the butterfly open 

 the governor will act as a check against 

 excessive speed. If, however, the steam 

 can be kept up continuously, not shutting 

 it off between cuts, with a butterfly, its use 

 should be discontinued entirely and a good 

 simple governor substituted. It may ap- 

 parently reduce the output of the mill by 

 putting a stop to intermittent high speed, 

 but it will also save the machinery and at 

 the end of the year when time and expendi- 

 ture for repairs, etc., are considered, it will 

 be discovered that more lumber has actually 

 been cut, expenses have been lighter and 

 the machinery will be in a much better con 

 dition than under the old plan of operation. 



