Machine Plant for a Modern Repair Shop.
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Selections from Olympia Exhibits. Suitable Tools for a Small Fleet.
By a Managing Engineer.
" The Manager of a Large Repair Shed," writing under the above heading in last week's issue, urged the necessity for the careful consideration, by owners, of the lay-out and equipment when establishing repair depots for motor vehicles, and the advice he then gave is evidently based upon special experience. I think, however, that most repair-shop managers would prefer to have wood-covered floors in preference to concrete for all departments except the washing and running sheds. Concrete is certainly cleanly and serviceable, but if by chance an expensive machined part should slip through a workman's fingers, as it will do occasionally, it stands a fair chance of being damaged if it falls upon concrete. Apart from the danger of fracture, however, there is the comfort of the workman to be considered, and I rather think that the lack of ordinary workshop comforts in a garage has much to do with the difficulty of inducing really first-class men to remain on that class of work after their craving for experience has been satisfied.
A Note Concerning Ventilation.
On the question of ventilation, too, I am hardly in agreement with the writer of last week's article, as I have generally found that hot-water pipes, while effectively heating a shop, cause a most objectionable odour, and one which induces violent headaches among the workmen. In my opinion, the hot-air system, either by natural draught from a stove or by means of a fan which forces air through an oven, is far the best, and, if the air be led into the building through pipes which are carried about 9 ft. or 10 ft. above the ground, whilst the outlets are the doors and a few diafts which lead from the floor level, the inrushing hot air will effectively displace all deoxygenized air through the bottom outlets, together with any petrol vapour, which, contrary to general belief, does not rise but floats about near the floor.
However., I did not set out to criticise last week's article, which has much valuable information in it. I rather wish to add to it the results of my own experience of suitable machine and hand tool equipment, the foregoing notes are only included by the way.
Choosing Repair Plant.
Every business man, having decided to go in for mechanical transport, and having decided upon the purchase of suitable vehicles, should unquestionably make full and careful provision for their proper maintenance and repair. If he decide that his fleet is to he large enough to justify the investment of the necessary amount for the purchase of machine and hand tools in a repair shop of his own, he should be careful that he buy only such tools as are likely to be needed. On no account should he lay down fancy or freakish machines. Having decided to purchase the necessary plant, the owner should make a careful survey of his vehicles, with a view to purchasing only such tools as will be needed to deal with parts which are likely to need replacement or repair. It is not always practicable to purchase renewal parts from the makers of the vehicles, although it is, as a rule, advisable to do so, and for that reason, if the fleet consist of six or more vehicles, the repair plant should be as complete as possible. A lathe, of course, is indispensable, and it should be one of heavy build with a good broad saddle, giving plenty of wearing surface and ample support for any work that may have to be bolted thereon. I have long had the opinion that the ideal lathe for a motor repair shop has not yet been made, and the exhibits at Olympia have not caused me to change that opinion.•
The Ideal Repair-shop Lathe.
In a motor-repair shop there are many jobs which require to have two or more parallel holes trued up, or rebored, and, with the ordinary type of saddle, this is a matter of uncertainty because it is almost impossible to set up a piece for a second boring in such a manner that the two holes will be strictly parallel to each other. If the cross slide of a lathe were made heavy enough to allow of its having slots cut in it, so that work could be clamped thereon, it would be an easy matter, after boring one hole, to feed over the cross slide until the second bore was in its correct position for tooling, and this operation could be executed without removing the clamping bolts or disturbing the work. Such a cross slide would, of course, reduce the effective height of the centres by the added thickness of the cross slide, but I see no reason why the headstocks should not be made .higher by that amount without greatly increasing their cost.
Some reader may say why not use a bigger lathe and have a special cross slide fitted, but one does not want to pay the price of the bigger lathe, when, under the conditions of work named, the lathe is not required to do any heavier work at 10 in. centres than it would have to do, with the ordinary cross slide, at 8it. in. centres. Why, then, should one have to pay the greatly-increased cost of the bigger tool ? Some makers claim to get the same result by packing up the heads. What is wanted—at least I think so—is a lathe with permanently packed-up headstocks and a cross slide with " T " slots of ample size. Perhaps some enterprising tool builder will produce one some day Now you, Mr. Drummond, are an unconventional and original tool designer. Can't you give us what is wanted?
In addition to its ability to take the largest diameter, and the longest piece which is required to be turned, a lathe should be capable of turning and boring accurately tapered work, and for use in conjunction with the lathe when engaged on such work, a good set of micrometer gauges should be provided.
Concerning a Shaper.
A shaping machine is not an indispensable tool, but it can generally earn its money in any well-ordered repair shop. It is a more suitable tool than a milling machine, for the simple reason that any special too/ that may be needed for a shaper can be knocked up out of tool-steel bar, whereas a special milling cutter is a very expensive thing to produce ; it takes a long time to make and calls for the employment of highlyskilled machinists and machines.
The type of shaper I prefer would be one capable of taking a 16 in. cut, but if 10 in. be considered sufficient for the parts on the class of vehicle employed, then one could not do better than consider the merits of the machine which is shown on Stand No. 117 by Messrs. C. Redman and Sons, of Halifax. As a, contrast to the American type of shaper with travelling table, this tool calls for special attention ; its fable is fixed, and lateral traverse, or feed, is obtained by a traversing saddle which is carried on a massive lied. With such a tool it is possible to machine a facing on one end of a tong piece, such as a spring palm on an axle forging, while the other end is supported from the ground on suitable packing pieces. Any price
from £40 upwards may be paid for a power-driven shaper, but I strongly advise that its design and capabilities be considered before its price. if the class of vehicle employed does not warrant the laying down of a power-driven shaper, possibly one of the hand-operated machines, such as the " Wotan " shown on Stand No. 222, by Messrs. F. M. Frye and Co., would meet all requirements ; these are really practical machines and are capable of doing good work within their capacity, and their price ranges from £13 upwards.
An Unpretentious Radial is a Good Investment.
The selection of the drilling machine or machines is a matter which calls for very careful consideration, and while a powerful radial drill is a very useful tool its cost is almost prohibitive, uniess there be plenty of work in the shops to keep it fully occupied—a condition which is not likely to prevail in many garages where fewer than 40 to 50 vehicles are maintained. A less pretentious radial will generally meet the bill, and a good example may be found on the stand. of Alfred Herbert, Ltd., whilst another good machine, and one which I know, from actual experience, is capable of good work, is made by Haworth, of Luton, and costs about £3:5. Machines of this class have both power and sensitive feed, and can tackle nearly every class of drilling required in a garage, except for frame work, and then a portable electric drill is almost unequalled. A sensitive pillar drill and a 22 in. pillar drill with power feed are useful additions, if there be enough work to justify their installa
tion, whilst a small twist drill grinder should certainly be included in the drilling equipment. Another class of machine which almost invariably pays for its space and keep is a disc grinder, with the aid of which, together with a plain grinder, rough forgings and castings can be reduced to the finished state in astonishing time. A wet tool grinder should also be laid down, but the total expenditure under the heading of grinders need not exceed 250. Messrs. A. Harper, Sons and Bean, on Stand No. 227, show several good types of grinders, and they are offering a good 14 in. wet tool grinder, in which the countershaft is an integral part of the design, for £16, and a good 12 insingle-ended disc grinder for 211 with plain table, or for £17 10s, with universal table.
As in Our Last Issue.
Of the sundry tools, fixtures, and plant required, your contributor of last week outlined them fairly completely, but I would like to add that a pair of " V " blocks, a straightening press and a mandrill press should also be included. It is not to be expected that a repair shop will include every type of machine which will be found in the shops where the vehicles themselves are built, but it is surprising what can be done with a limited outfit, if the tools are handled by skilful men. All sorts of jobs mist be executed, at short notice, in a motor-repair shop, and, generally speaking, ingenuity and careful workmanship must take the place of expensive equipment.