Workshop and Production Section AIRCRAFT ENGINEERING January, 1939 By J. G. Willis, A.F.R.Ae.S., M.I.Ae.S. N the recent lecture on U.S. Methods of Aircraft machine with a jig template in position on the seem opportune at this time to encourage the Production given by Mr. T. P. Wright before table complete with plates ready for cutting. interchang e of ideas for producing aircraft com the Royal Aeronautical Society* the methods Fig . 2 shows the construction of the jig template ponent s in this country. Nothing but good could shown for cutting duralumin plates will be of which is simply a multiply board with rectangular result from this, since every firm, both large and interes t t o many people. Perhaps a brief description section wood runners along two edges. The metal small, could contribute and receive benefit, not of a simple arrangement for cutting small blanks, templat e is secured to the underside of the board only directly but even more through raising the which has been much used in America, will also be an d where possible two or three bolts are extended general standard of aircraft development and of interest and use to some readers. throug h the board for bolting down the plates manufacture . The engineer, a t any rate, would generally prefer to be cut, which would obviously be pilot holes in to produce small plate work in the appropriate th e finished plates. punch or press, and the modern aircraft toolroom Several plate s can be cu t a t each setting depending has shown considerable ingenuity in producing on the thickness. The operator holds th e template economical tools just to cover the quantity usually agains t the roller protruding through the table, required. There are, however, so many variables to while the cutter produces the blanks. contend with, such as quantity , thickness, material, There are, of course, many other uses for the area, finish, etc., not to mention presses that are machine in light milling operations for fitting and available at the time, that methods of directly modifying extruded sections and several refinements cuttin g out blanks by means of a typ e of high speed will probably suggest themselves, such as an woodworking router have received considerable adjustabl e table and automatic compressed-air attentio n for light alloy fabrication. cleaning. Fig . 1 shows a very simple arrangement of such a Importan t advantages are the finished edges produced on the blanks and the simple, cheap and *U.S. Methods of Aircraft Production, by T. P. Wright, AIRCRAFT light jigs required. ENGINEERING, Vol. X, December, 1938, pp. 386-411. A modification of the method described, which ha s also been used, consists of clamping the work t o a baseboard in sandwich form, with the stock material next to the board and the template on the top . Suitable packing strips are interposed for cutte r clearance. A roller follower is fitted just above th e cutte r t o follow th e templat e and the work proceeds in a similar manner to that shown in Fig. 1. An extension of the above processes takes the form of a balanced pantograph linkage system in which a follower traces round the template at one point while the cutter reproduces the work at anothe r point. When one or two thousand aeroplanes are ordered from a firm, engineers know what to do about it; bu t in considering general development it would FOR THE ENGINEER VER Y engineer knows the damage that can be done to delicate parts by the over- zealous use of a hammer. The problem is, perhaps , even more acute these days in the aircraft A Synthetic Rubber industr y than it was before expansion led to a shortage of skilled and trained men both in the factory and on the aerodrome. twelve months that had elapsed in the intervening Hide, rubber, wood or copper mallets have been T will be remembered that the August, 1937, issue of AIRCRAFT ENGINEERING contained an twelve months. in use as safeguard against damage for years; but article on "Synthetic Rubber Materials," Continued progress has been made in the pro mos t makes have suffered from a short life and pointing out the oil and petrol-resisting qualities of duction of these new materials, and we have hav e been difficult to get re-filled. various materials of this class. This was followed recently had brought to our notice a synthetic in July, 1938, by a further article entitled rubbe r known as "Hibudine," which has been "Syntheti c Rubber Substitutes" dealing with the developed by Paul Quinn, Ltd. This material can later developments that had taken place during the bo produced either in liquid form, for application to sheets or castings in steel, aluminium, duralumin, magnesium and other metals, or moulded to any shape. It is specially compounded to resist abrasion from flying particles as agains t direct contac t friction. An interesting use of Hibudine is as a high temperatur e adhesive. It is, for instance, employed a s a bonding medium between the friction linings an d opposed surfaces of clutch plates and brake diaphragm s where it takes the place of the rivets. Th e photograph illustrates an application of Hibudin e for bonding and securing together metal Fro m the point of view of general utility and an d light alloy components in oil coolers and radia replaceability the Thor copper and rawhide hammer tors . The material is here used in place of brazing or is a remarkably useful tool. Combining, as it does, soldering, and allows the use of light alloy tubes, th e very soft rawhide, for use where danger to between which it provides a resilient jointing, thread s or aluminium parts is concerned, with the permittin g expansion, contraction and absorption sharper rap of the copper—still without the damag of vibration with saving in weight. ing effects of a steel hammer—it provides a safe Exceptionally strong and light flooring panels for mallet for any material. It is the dual ends of this aeroplanes, down to 12¾ oz. per sq. ft., can be hamme r which give it its qualities and make it produced faced with aluminium alloy or magnesium indispensable to any aeroplane engineer's tool kit. or birch veneer ply and rendered waterproof by The illustration shows how the striking sections of impregnation and bonding with Hibudine. the hamme r are held in an iron head attached to an Th e material is a pure synthetic rubber based on ordinar y wooden shaft. The copper and rawhide Neoprene. It can be formulated in various grades end-pieces are independently replaceable when for various purposes. As an example, particulars worn. The hammer is in use with a number of the of "Hibudin e Stock 28 " are as follows:—Tensile large aeroplane constructing and operating com strength , 163 kgs. per sq. cm.; Elongation, 839; panies and the makers, the Thor Hammer Company Modulus of elasticity at 500 per cent. elongation, of Birmingham, have arranged a special nett price 82 ; Permanent set at 500 per cent. elongation, for the aircraft industry of what is already a very 12 ; Hardness (Shore scleroscope), 39-40. cheap, but first-rate, article.
Aircraft Engineering and Aerospace Technology – Emerald Publishing
Published: Jan 1, 1939