VICTORIAN INSTITUTE OF ENGINEERS:
would very likely cost nearly as much as a steam motor, even without the paraphernalia of power house, transmission lines, and possibly hydraulic head works. No doubt these light rail- ways were principally put down where wood was cheap, and in that case fuel economy was not a very great matter, for they might just as well burn it in the locomotive as 3o or 5o miles away at a power station. It became a question of interest on a larger capital.
PAPER.
NOTES ON MODERN MACHINE TOOLS.
By M. EADY.
The past 15 to zo years have brought the machine tool de- signer and builder many serious problems. The call of com- merce for rapid production, and the introduction of high-speed steels, the qualities of which have rendered it possible to greatly increase speeds and feeds, have made it imperative for many complete re-designs. These changes have been so rapid and radical that in many instances the new problems of yesterday have become the old ones of to-day. Machine tool builders have responded to the new conditions, and it is my intention to point to some of the alterations in some of the latter tools, which are to-day playing such an important part in general engineer- ing.
Attendant with the call for rapid production has come the demand for accuracy, and to-day the designing engineer relies upon obtaining accurate work. We know this to be true in the case of designs of steam engines, explosion engines for auto- mobiles and flying machines, as well as pieces of intricate me- chanism. Those who are connected with workshop practice know that the old eft. wooden rule is becoming, or should have become, as rare as the dodo, as a means of measurement to the machinist. To-day the micrometer should take the place of the ordinary rule, and .a system of limit gauges to enforce accuracy.
Even now, however, we . have turners or machinists given in- structions to make the job "a good, solid fit,"or a "fairly loose fit" ; one even still hears the old expression of making a job larger by the thickness of a piece of paper. These terms are
74
MODERN MACHINE TOOLS. 75 well enough in their way, and I know that many good jobs are made by operat6rs working to such, instructions, but modern prac- tice demands absolutely accurate work, and draughtsmen should indicate upon the drawings the decimal part of an inch they re- quire a fit to be made. Good data on this matter are easily, ob- tainable. I certainly think that the matter of accuracy should be appreciated by all engineers; designers should demand it, and shops' management see that it is obtained.
As the machine tool designer has responded to the call for accuracy, there is now no excuse for shop practice not providing correct work.
To ensure accurate results, the machine tool has had, of course, to be designed to give accurate results without alto- gether depending upon the skill of the operator. Thus we have the tendency of designs to lessen the skill of the operator, and this is the reason why so many automatic and semi-automatic lathes and machines have come right into the engineers' work- shop.
As these types of machines were making their appearance in the shops, high-speed steel came upon the market. For many years steels were gradually being improved, but really the spurt was given about 1902, when the technical papers talked practi- cally nothing else but high-speed steel. Then we had the ex- tensive trials, held in Manchester in 1903, which gave the ma- chine tool designers their first reliable data.
Like every other improvement, high-speed steel has had to fight its way into the workshops, but I believe that to-day .engineers throughout the engineering world fully recognise its true value. For a considerable time, it was thought to be only
a proposition for rough cutting with the tool used in the ordinary lathe; then its use was extended to twist drills, with somewhat remarkable results. Even after this, it was considered only problematical for general machine tools, where ordinary steels were used w;th plenty of lubricant ; but to-day makers of prac- tically all classes of machine tools recommend high-speed steel for attaining satisfactory results.
In regular shop practice, we now have, beside high-speed lathe tools, high-speed milling cutters, high-speed cold saws, high-speed twist drills, even extending to chisels and files.
To give an idea what changes can be brought about by the
76 VICTORIAN INSTITUTE OF ENGINEERS :
introduction of high-speed steel in the cutting speeds alone, the following figures may be taken to fairly indicate the relative old- time speeds and the modern practice :—Lathe cutting tools, from 40 feet per minute to go feet per minute; drilling, from 38 feet per minute to 104 feet per minute; milling, from 25 feet per minute to 6o feet per minute. To obtain results such as these, it certainly means power and rigidity, hence the re- designs to give ample driving power, and to withstand heavy internal strains.
Taking a period of, say, 15 years, we may safely state that, generally, driving powers have increased by 300 per cent., and weights by over loo per cent. These changes, of course, did not come with a rush, but in many instances are the outcome of re-designs by tool-makers, who have specialised in making one line, and who have gone to a great expense experimenting.
This matter of specialising, we know, has now become one of the most serious thoughts to engineers in practically all branches of the profession. Probably the foremost in this movement in engineering were the machine tool makers in the United States.
The day is rapidly' passing for the machine tool maker to make a large range, the rapid strides in design calling for a heavy cost in both designing and experimenting. Thus the full thought of the machine tool builder must be concentrated on, as near as possible, one particular line.
To give an idea of the cost of experimenting with machine tool designing, recently a firm making milling machines spent over £5,o0ó in thoroughly testing one size of machine which they were placing on the market.
A proper study of the physical and chemical components of the parts of the machine is now having serious consideration.
and some of the large machine tool makers have their own laboratories, so that the various strains and stresses may be taken by materials thoroughly suitable for their duties.
Another important factor that has grown with the intro- duction of these machines is the tool-room staff. This, as a rule, consists of trained mechanics, who make a proper study of tools and attachments for the various machines, and who take charge of the designing, making, and setting of cutting tools, fixtures, and jigs. This is really the keynote of the suc- cessful operation of modern machine tools. The tool-room staff
e
3
MODERN MACHINE TOOLS. 77 should be proVided with a proper equipment, and have the full
responsibility of keeping the cutting tools, and the machine operator should not be relied on to sharpen the cutting tools, but as soon as the tool is dull, it should be replaced by one obtained from the tool-room.
A prominent feature in the design of the modern tool is the convenience of the machine for the operator. Possibly, the most pronounced feature in this connection is the means of changing the driving speeds and rates of feeds. The usual method of a stepped cone is gradually disappearing, and its place is being taken by gear boxes or variable speed motors. Changing by gears is usually arranged to the medium-size machine tools, and variable speed motors to the large machines.
The introduction of nearly perfect gear-cutting machines, and the use of case-hardened steel gears, have made the gear- boxes practically noiseless. Examples applied to the various machine tools I will presently show on the screen.
An interesting feature in machine tool designing is the mas- siveness of the machines for doing gun' and shipbuilding work.
One of the large machine tool makers in Manchester recently told me that one of the most serious considerations was, when would the limit be reached with regard to size of ships of war and commerce? When one thinks of the tremendous size of the turbine cases in these large vessels, one soon realises what size machine it must take to bore and face them. Then the work of boring the guns can only be accomplished by mammoth tools.
The lathes for this work often weigh over 25o tons, and are usually driven by motors of t5o h.p. and upwards.
Grouping the mechanical changes, I think they can be briefly stated as:—
I. Strengthening the old standard designs to secure rapidity
of production and obtain accurate results with high-speed steels.
2. Introducing new features in both general and detail de- sign, so as to enable operators to produce rapidly, with les- sened physical and mental strain.
The results of these changes have meant that not only can manufacturing . costs be reduced, but more satisfaction is given by the workman. Speeding up a slow workman on a slow- action machine generally leads to friction, whereas on a tool de-
78 VICTORIAN INSTITUTE OF ENGINEERS:
signed with convenient motions, an operator soon becomes in- terested in obtaining a rapid production.
Certainly capital cost has greatly increased, which weighs on a modern equipment rather heavily. Also has the cost of power increased ; but in this direction it has been easily proved that, pound for pound of metal removed, the cost of power is less on the new machine than on the old, thus a great saving must be made in the operators' time. Well, that is just where we now want the saving, especially in Australia, where our skilled machinists' labour is so highly paid.
I admit that it is a difficult problem for the workshop manager, oftentimes, to approach his principal, or, worse still, a board of directors, with a scheme of reorganisation in his machine tools.
Unfortunately, the laymen's idea of machine tools is a very hazy one, and he usually expects the workshop management to pro- duce cheaply with a plant having a low capital cost.
However, when these offhand considerations are passed over, I think it must be conceded that the public at large owe a debt of gratitude to the designers of modern machine tools. It has been through their ingenuity that many of the every-day con- veniences that we now have are possible to reach the multitude, and not only the few.
After the paper had been read the author illustrated the details of the various machines described, by the subjoined lantern views :-
Lathes.—Showing the difference in design between the old types and the modern high speed machine ; special reference being made to the new pattern geared head stocks, and to the convenience of operating the feeds and screw-cutting mechanism.
Semi-Automatic Lathes.—The latest pattern will reduce a mild steel black bar from l Iz in, to Min. in one cut, removing 8.8 lbs.
material per minute.
Automatic Lathes.—Various types of work. Comparisons were drawn as to the rapidity of production on this type of tool.
Large Wheel Turning Lathe installed in Newport Workshops for rapidly re-turning old tyres.
Upright Drilling Machines.—Showing contrast in design of old and new in both Pillar and Radial Machines. An upright machine was shown in the operation of drilling a Min. hole through a cast iron block 21Z in. thick in 8 seconds. The type of Radial Drill shown was one driven by variable speed motor, and arranged with quick feed actions, also convenient arrange- ments for manipulation.
Milling Machines.—Various types were illustrated, showing the advance in design from the old light machines to the high power horizontal and vertical tools of to-day ; both these types of
~i lll üll
I rlf
DISCUSSION—MODERN MACHINE TOOLS. 79 machines are now fitted with gear changes to the speeds and feeds.
Gear-Cutting Machines.—Those dealt with were the Brown and Sharpe type gear cutter, hobbing machines, and bevel gear shapers ; all these types of machines of the class now largely used in the automobile industry.
Large Boring and Facing Machines, both. horizontal and vertical, High Speed Slot-Drilling, and Planing Machines, and Boiler-yard Steel Section Punching and Shearing Machines were also illus-
trated.
DISCUSSION.
The PRESIDENT, after moving the vote of thanks recorded in the Proceedings, said there were so many interesting points that he was sure it would be quite impossible to do justice to the Paper that evening. Each one of the machines Mr. Eady had shown them was a type of a number of others. Each one might be taken to represent some zo or 3o machines, which differed from the others; each difference was of importance, and would doubtless provide material for discussion for many evenings.
But there were one or two general points that appealed to him very strongly. Firstly, the entire revolution that the machine had worked in the human element of the industrial scheme. Not very many years ago a man would be expected to have an exact knowledge of any one of the machines that were prototypes of those they had had explained. He would be expected to work them reasonably well, and would need to have a considerable amount of experience and adaptability. Now the man required Very much less brain than his predecessor required. The machine detail had largely taken the place of brains, and the brain work had been done in the drawing and designing office and the labora- tory. That had made a very great difference in the type of workman. The machine-shop workman was a specialist on nar- row lines. That appeared to be the main difference between the workman of to-day and the man of years ago, who was required to have considerable general knowledge.
Another feature was the far greater weight of tools. This had followed as the perfectly natural consequence of the newer cut- ting steels. Not very long ago carbon steel was the only cut- ting steel. That could not be run af a very high speed without
heating and softening; nor, for the same reason, could they take a very heavy cut. Therefore, the machine need not have a a-
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very great weight. Then followed chromium, tungsten, and the vanadium alloys, which retained their cutting powers even when considerably heated. With each advance the speed of possible cutting had thus been increased. With such alloys and the higher speed, necessarily greater power had to be put into particular machines, and the machines had to be built heavier.
The gearing, the greater belt power, the greater speed, the greater weight, were all necessary consequences of the newer cutting steels. And they might expect that the machine maker would take advantage of each future metallurgical improvement, and produce still heavier machines.
Mr. Eady had referred to the necessity of accurate measure- ment. But an accuracy of the to,000th of an inch was not very difficult to get, and was often obtained in work of precision.
And, as to working to "the thickness of a piece of paper," in the modern shops that was a matter of the past, and the order was not given in terms of " tight " or " slack," but in decimal to the to,000th of an inch, when the work justified that degree of accuracy. With the gauges as now used a standard reliable within the to,000th of an inch was always assured, and in general practice truth of standard to the ao,000th of an inch could usually be obtained. In that particular respect he did not think the gauges in point of accuracy were very much in advance of those of forty years ago. Whitworth's gauges, then, were pro- bably as accurate (though far more expensive) as any turned out at present.
One expression had struck him personally—that the milling machine had fought its way into the workshop. He had intro- duced the first milling machine into the Government Depart- ments of Victoria, and he well remembered the criticism that was directed against him, and the unkind things that were said about the milling machine. The men had a prejudice against it because they thought it would take the place of hammer and chisel and file; and so it did. Certainly here, and almost every- where, it had to fight its way in.
Discussion adjourned.
I00 VICTORIAN INSTITUTE OF ENGINEERS:
NOTES ON MODERN MACHINE TOOLS.
The PRESIDENT sa d Mr. Eady in his paper had put so very much information before them that discussion was very difficult.
If he had dealt with some particular tool and outlined its points there m ght have been more probability of discussion.
Mr. J. T. N. ANDERSON said it was a pity if this important sub- ject should be closed. The mechanical engineers belonging to the Institute might possibly contribute if they kept it open to another meeting.
Discussion adjourned.
PAPER.
THE MAIN ROAD PROBLEM.
By J. T. NOBLE ANDERSON.
(Past President.)
Main roads are generally devoted to Government and other public uses, as follows:—
(A) Government Uses—
(I) Rapid transit, including not only direct Government des- patches, but the postal and telegraphic services, which the Gov- ernment almost everywhere conduct as a trading business.
(2) Military transit and transport.
(3) The means of access to, and service of Government pro- perty and reserves, whether devoted to mining, forestry, water reserves, State or Government railways, canals, hospitals, asy- lums, and other such properties and factories as the Government may possess.
(B) Other Public Uses— . (I) Commercial transport of goods.
(2) Transit of passengers, whether for business or pleasure 3) Tourists, whether by motor or coach.
(4) Travelling stock.
DISCUSSION-MODERN MACHINE TooLS. 117 That extract, wnilst cLc.ar.ng that the Architects did not know what the attitude of other bodies was, now admitted that the ex- plicit d ssent of the Inst_tute of Engineers of Western .Australia was in the possesson of the R.V.I.A.
But the issue was that the Architects publicly claimed that their demands were supported by those bodies, and the statement was publicly reiterated after it had been formally contradicted.
There was little doubt that the Royal Inst_tute of Br. t.sh Archi- tects was influenced by those statements in its action of request- ing the alteration of the constitution of the board of selection, in order that it might contain architects only—to be elected by local architectural bodies, ` nstead of, as at present, an engineer, an architect, and a surveyor.
The following memorandum, dated August 17th, from the Sec- retary to the Federal Department o: Home Affairs, would show that the attempt to vary the conditions had failed, and that the demand of the R.V.I.A. had been refused :-
"Dear Sir,—With reference to your communication of the 13th ult., forwarding copy of a resolution relative to the question of the Federal Capital Site Competition, unanimously agreed to at a general meeting of the Victorian Insti'Aute of Engineers held on the 12th idem, I desire to inform you that the Min- ister for Hame Affairs has decided that there shall be no alteration in the conditions which have been issued for the guidance of intending competitors in the preparation of competitive designs for the proposed Capital City.—Yours faithfully,
(Sgd.) DAVID MILLER,
Secretary".
DISCUSSIONS.
NOTES ON MODERN MACHINE TOOLS.
The PRESIDENT declared the discussion on Mr. Eady's paper open. As there was no further contribution, he called on Mr.
Eady to reply.
Mr. M. EADY said his paper dealt with a large range of mat- ter, and it was written with the intention of showing the general advance that had taken place in machine tools within ,a period of, say, ten or fifteen years. He did not think it was a matter that could be very deeply discussed, because he had not made any main point that could be torn asunder..
I 1 VICTORIAN INSTITUTE OF ENGINEERS:
But he thought that the results which he had brought forward wou:d show that the des'gners of machine tools had not been asleep. He thought the trend of commercial engineering had been along the lines of the machine tool builders. As he had stated in the paper, the tremendous amount of work that was being done to provide for the benefit of the people had been the outcome of the irgenu'ty of the engineer; and the public at large owed a great debt to those designing heads. To a certain extent, the craftsman was being displaced by the up-to-date tools, but certainly costs were being greatly reduced.
The PRESIDENT said Mr. Eady had given them a great deal of material that must prove of use to them. He thought all would agree that engineering in none of its branches could stand where it stool to-day were it not for the progress made by mechanical engineers in recent years.
Discuss-on closed.
THE MAIN ROAD PROBLEM.
The discussion on the paper on "The Main Road Problem"
was resumed.
The following contribut'on from Colonel J. MONASH was read:—
Both " in the paper, and in the subsequent discussion, the ne- cessity for a topographical survey of the State has been referred to; but to judge from the terms of these references, and from similar remarks in other recent discussions of this Institute, It is apparently widely believed that very little has yet been done in this direcfon. It is, however, with:n my personal knowledge that a very great deal has been, and is being, done—primarily for mili-
tary purposes. Mr. Griffiths has alluded to the work recently done in the Kilmore district as a contour sketch of the locality of the camp, This is doing but scant justice to a very minute and de- tailed and very compete piece of topographical survey work. kn area of upwards of 15o square miles at Kilmore, and another of zoo square miles at Seymour, has been very completely mapped, at a scale of i mile to the inch, with contours at Soft. vertical in tervals; these maps not only show, as faithfully as can be done to so small a scale (the same scale as the British Ordnance Sure vey) the conformation of the ground surface, but also indicate
