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.
This machine should be located in the tool room, and all took requiring to be ground should be sent there and exchanged for like tools properly ground and held in stock ready for issue. This exchange should be made by errand boys, who should keep the operators supplied with sharp took. Operators at the machines should not be allowed to grind took except in rare cases and by order of the foreman.
The arrangement of machines with relation to each other and the transportation facilities necessary to serve them in an efficient manner is a problem that is not often satisfactorily solved. Here again the particular nature of the product to be turned out must be taken into consideration and the requirements carefully considered and worked out in accordance therewith. The product might be large and heavy engine work, which would require a certain arrangement of machine in order efficiently and economically to carry the parts through the works. Or, it might be machines composed of many comparatively fight and easily handled parts, which would necessitate quite a different array of machines and located upon an entirely different plan. Thus we see that the nature of the product will govern, not only the selection of proper machines, but the location of these machines in relation to each other. Necessarily this latter condition will decide the character and location of the transportation facilities necessary.
A specific example will, be given from which general principles may be deduced that may be applied to other and quite dissimilar cases.
Fig. 210 shows the original arrangement of the. machines in a department in a manufacturing concern, in which there was a large volume of heavy planing. In the bay at the right of the plan was a group of large planers, while those of medium size were located at the rear of the main room, and a single small one at A in the bay at the left of the engraving. The main group of lathes were placed along the front of the main room, with a section of small ones along the outer or street wall as shown. There was a medium-sized lathe at B, and a heavy 68-inch swing lathe at C. Also a chucking lathe at D, near the right part of the engraving. In the main room were two upright drills near the door N, and along the rear wall near the small planers a polishing head at E, a polishing belt at F, and an old-time suspension drill at G. Near the group of small lathes there was a sensitive drill at H, a slotter at J, a bolt cutter at L, and a horizontal hydraulic press at M. It will thus be seen that many of the machines were apparently located at random and with little regard for any definite plan as to their uses or the progress of the work.
Fig. 210. The Original Plan of a Shop Department.
In the operation of the shop, castings were received at N, the heavier ones put on trucks and taken to the group of large planers, many of them brought back to the upright drills, near the door N, some taken to the 68-inch lathe at C, and then back near the group of large planers to be erected. Forgings came in through the door at P, went to the planers in the main room, the lathes opposite them, or those in the left bay, then to the hydraulic press for force fits, then back to the erecting floor at the opposite end of the department.
Face plates were roughed off on the large planers, carried to 68-inch lathes at C to be turned, and, after a more or less wandering career, finally arrived at the erecting floor. Dirt and dust from the polishing head at E and the belt at F was quite injurious to the machines in the vicinity. Transportation facilities were crude and the continual moving of material and work in progress back and forth was not only expensive, but kept the main passage in the center of the room in a constant state of congestion and blockade much of the time.
The plan for re-arranging the shop is shown in Fig. 211, and was as follows: The group of large planers, those along the rear walls of the main room and the group of large lathes opposite to them were not disturbed. The other machines were moved to the locations shown. The left bay was practically cleared of machines and made an erecting floor, the lathe B being retained for convenience of small jobs during the erecting work. The group of lathes were eliminated altogether as they were no longer needed. A polishing room was built and the machines E and F placed in it, thus confining the dust and dirt nuisance in a small space. An overhead traveling crane was set up covering the entire space of this bay, giving great convenience for the erecting of machines. A small tool room was built and in it was placed a tool grinder Q and a twist drill grinder R. A door for the receipt of castings at 5, and a floor scale were put in. Shop tracks were laid as shown running from the door 5, across the scale and on to the group of large planers at the rear; also, through the center of the main room, from the doors P to N, with a turntable at the intersection of these tracks. Branch tracks run through the center of the erecting floor to the door X.
The planer A, formerly in the left bay, was added to the group of planers at the back of the main floor, and beyond them the two upright drills were placed, and still further beyond the sensitive drill H. Beyond this were located the bolt cutter L and the chucking lathe D. A large radial drill was added at T, and a vertical boring mill at U. The old-time suspension drill at G was replaced by a modern "railroad" drill at V, that is, one over the shop track upon which was fitted a special truck for supporting heavy lathe beds to be drilled. An ordinary jib crane was set up at W, for the use of the planers.
By this arrangement most of the castings were received at the door S, weighed on the scale located there, and then moved on shop cars to the large planers. Beds were scraped and afterwards drilled at V, and sent on shop cars to the erecting floor. Work requiring the use of the radial drill or the vertical boring mill was handled near the point of receiving castings and sent on in the same way. Face plates and spindles were finished on machines near each other and forwarded over the same line. Forgings were received through the door P and sent over the shop tracks to whatever machines were to perform the next operations upon them. Thus nearly all the work, particularly all the heavy work, was kept moving in the same direction toward the erecting floor, and the finished machines shipped out of the door at X.
Fig. 211. Plan of Department as Re-arranged for Greater Efficiency.
By this arrangement there were no blockades, the cost of transporting materials was enormously reduced, and the output of the shop very considerably increased. An annual outlay of nearly $4000 for handling material was reduced to less than one-fourth of that amount and the work of the shop ran smoothly and satisfactorily.
The discarding of the six lathes paid for the vertical boring mill and the radial drill added, so that there was only the expense of the change from the old suspension drill to the railroad drill to add to equipment expenses, other than the shop tracks and cars and the two cranes, all of which were made in the shop. These were paid for out of the savings in transporting and shipping during the first twelve months and quite a balance left on the right side of the ledger.
Such results, or those of similar nature, can nearly always be achieved in very many of the older shops by systematic planning of machine operations, re-arranging the machines to suit a proper sequence of operations necessary for efficient and economical work, and providing proper transportation facilities. The subject so treated will tend greatly to increase the efficiency of the machines.