Eom Drivers kMechanics
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Send ta an account of any *dal incident of your work or experience. If suitable, we will edit your notes, supPly a sketch when required, and pay you for everything published. Mention your employer's name,
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Light up your Lamps at
5.17 on Thursday ; 5.19 on Friday ; 5.20 on Saturday ; 5.22 on Monday ; 5.21 on Tuesday ; 5.26 on Wednesday.
A Quick Method of Relining Brasses.
The sender of the following communication has been awarded the 10s. prize this week.
[1419] " (Christchureh) writes:—" In super vising the overhauling of vehicles which come into our garage, I have often to design tools and appliances for economically effecting various ma-chining operations and repairs which are to be carried out.
" The matter of remetalling bearing brasses has, up to now, given a lot of trouble, and so I set to work to build up a rig which would enable brasses to be re-lined with a minimum amount of time and trouble, and without. risk of flaws. I may say that the appliance which I constructed is giving every satisfaction, excellent results being exnerienced even from the first set. of brasses lined.
" I certainly think readers of your D. and M.' pages will be interested in my Particular method. therefore send to you full details, and enclose a cketch [We have had this redrawn.—En.] of the arrangement. "The principal component part consists of an angle
ylate, made out of a piece of mild steel, bent at right .angles and planed square, dead true. It may be made in wrought or cast-iron if convenient. The half-mandrels I constructed out of a piece of iron piping, which was first machined on its outside diameter and afterwards sawn in half along its centre, the size of pipe utilized being, of course, suited to the bore of the brass to be remetalled.
" I tapped the pieces of split tubing to enable them to be bolted upright to the angle plate by means of a set-pin, cutting a slot in the plate to allow for any variation of the positiott of tapping on differentsized half mandrels.
" For holding the brasses in position for re-m.etalDI ling I made a clip out of mild-steel sheet, of stout gauge, after the form shown in the sketch. This completes the rig. Details for the actual relining are as folio w.
'Before commencing operations on the brass, the worn white metal should, of course, be carefully melted -out, and the shell thoroughly cleaned and tinned. After clipping it in position on the angleplate, the whole rig should be well heated, and the new metal afterwards poured into the space between the brass and split tube. Immediately the lining has set, the clip may be loosened and another brass placed ready for pouring.
"I find that, with this apparatus, my men can remetal bearings of a given size at the rate of one every three minutes. Providing a stock of various-sized half mandrels be carried, there should be little delay in satisfactorily turning out relined brasses for any size of engine which is likely to come into the -shops for overhauling."
Insulation Tape makes a Petrol Joint.
[1420] " (Dartford) writes :-" Whilst I was recently driving a. four-ton lorry from a large brewery in Birmingham to Coventry, I had the misfortune to have the petrol supply-pipe break, the fracture occurring immediately underneath the float-chamber. As soon as I discovered the trouble, I turned off the fuel and considered for a moment how best to make up the joint, as I was some distance from, a garage and had no means myself for immediately brazing an a. new nipple. " However, upon a little consideration I effected a simple form, of repair. I filed the broken end of the pipe down smooth, and cut. a couple of rough grooves round its circumference. I always carry insulation tape in the tool-box, and, procuring a piece of this, wrapped it round the end of the tube, pressing it. well into the groove-s.
'Discarding the broken nipple. I screwed home the union nut, which, of course, had been placed on the pipe before wrapping round the insulation tape.
"This method made quite asatisfactory joint, and enabled me to proceed on my journey. I examined the repair occasionally for possible leakage, but experieneed no further trouble, the tape-made joint holding out until I brazed on a. new nipple at the Birmingham headquarters the same night."
Removal of Valves Made Easy.
[1421] " R.T." (Bedford Hill) writes :—" After often experiencing some difficulty with regard to taking valves adrift from various types of engines with which I come in contact, I decided to utilize a valve-lifter of the form illustrated in the sketch herewith We have had this redrawn.—Enet I do not claim originality for the idea ; it is possible that the device was made use of on old types of stationary gas engines.
" The lifter itself consists of two parts only, viz., a forked lever, as shown in the small diagram, and a
removable fulcrum link, which is also included in the sketch. These two parts I forged from Ji in.-round mild steel. Their dimensions, of course, will depend upon tho particular pattern of engine for which they are intended. The anchorage for the link is provided by an eye-plug, Which is screwed into the cylinder jacket in some convenient position.
" The method of raising the valve-spring, in order to remove the cotter, will be understood on reference to the general arrangement. To prevent the valve itself from lifting during the use of the fork lever, I placed_ a piece of wood of convenient size on the Lead of the valve and held it in position by screwing the valve cap down on to it,
" The convenience of the kurangement, and the case uit.h which most obdurate valves can be removed, quite justifies the little trouble involved in the construction of the lifter. This particular device, I find, has also an advantage that can be claimed for few valve-lifters in that it is perfectly direct in operation, and the usual tendency of the lifter to slip during the process of raising the valves, as experienced on some forms I have used, is entirely done away with."
The Voltmeter as a Speed Indicator.
[1422] "E.E.II." (New York) writes :—" The vehicle of which I have charge is equipped with an early type of electric-lighting system in which there are no means provided for maintaining a constant voltage in the lamp circuit other than an automatic cut-out. Consequently, with the old pattern of dynamo utilized, the voltage is constantly fluctuating, the variations taking place almost directly as the speed of the motor.
" With this state of things, upon a little consideration of the matter, I realized that the voltage, as eanded by the voltmeter, is practically a measure of the speed at which the machine is travelling. I took advantage of this fact and carefully drew out a scale, graduated in miles per hour, and pasted it in position on the glass over the dial of the voltmeter. Thus the instrument, in addition to its ordinary duties, serves the purpose of a speedometer. The scale, of course, was made so as not to interfere in any way with the reading of the voltmeter.
" For calibrating the speeds in miles per hour, borrowed a speedometer from a friend in charge of a similar make of machine to the one I myself drive ; the recorder was fitted up temporarily and I got hini to operate the vehicle whilst I made careful observations and marked off the new scale to correspond with the reading of the speedometer.
" Had it not been convenient to borrow a recorder, I should have got a driver of a machine equipped with one to pace my own vehicle, and, with someone else steering, myself have marked off the graduations corresponding to signalled speeds. " When changing gear, or /tinning at low speed, the device is, of course, valueless as a speedometer, it serves its purpose quite well, however, when the lorry is travelling at higher speeds. " It proves equally as useful at night-time, whcn the lamps are all switched on."
T3 Prevent Your Valve-caps Sticking.
[1423] " J.L." (Aylesbury) writes :—" Whilst recently overhauling the engine on the vehicle which 1 drive, I experienced a considerable amount of difficulty in getting the valve caps loose from their seatings, and I had to utilize a spanner lengthened up with a large piece of tube to enable me to get sufficient purchase for the job.
" I determined this should not occur . again, so, before screwing the cans into position, I gave the threads a liberal supply of graphite. This, of course, is a comparatively old idea with fitters, but in any case, the man who erected the engine to which I refer could not have known of such a simple preventive."
Impressions of a Leyland.
[1424] " H.J." (Pimlico) writes :—" Although, in the matter of driving experiences, my own cases are those connected with the petrol-driven vehicle, nevertheless have read with much interest the experiences of my fellow readers who drive steam wagons. I consider that impressions from bath sides tend to stimulate us to get the best results out of our machines.
" Enclosed please find a few particulars, and a photograph [We have had this reprodueed.—En.] of a 40 hp. Leyland War Office Subsidy type of machine, which I have been working. I have driven many machines in my time, arid this model quite comes up to my expectations.
" it is capable of driving up steep inclines with a load of five tons without labouring ; this is borne out by the fact that I have climbed Blackheath, Putney and Kingston hills with the machine fully loaded, and did not. have to drop to lower than second speed.
" The engine is governed to cut out at 161 miles per hour, and the machine has a ,cioulde-reduction gear in the -back axle. I have not vet experienced any mechanical trouble, although the vehicle, at times, has been called on to carry as much as 20 tons a day from the docks, the distance out varying from 12 to 20 miles ; this, of course, meant carrying :Four and fiveton loads for many consecutive days. The tires fitted are Continentals, and 1 find that they act practically as non-skids, and are well suited for working this type of lorry in all weathers.
" I have just accepted an offer to take charge of a fleet of machines for a large firm, and I must say that
certainly regret leaving such a fine model as this 40 h.p. Leyland"