Lamps Alight.
Page 21
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Light your lamps at 9.38 in London, 10.12 in Edinburgh, 10.5 in Newcastle, 10.1 in Liverpool, 9.51 th Birmingham, 9.48 in Bristol, and 10.43 in Dublin.
Cutting Left-hand Threads with Right-hand Tackle.
The sender of the following communication has been awarded the 10s. prize this wed.
[1746] "(;".B." (Hornsey),writes!—" I used to be a. regular contributor to your D. and M.' pages some years ago, but owing to special circumstances contributions of mine have not for some time figured on that page.
"It has occurred to me that a description of the method of cutting left-hand threads when only righthand thread cutters are available may be, or interest, particularly so at the present time, when the diffibulties in the way of repairing broken-down vehicles /lie greater than they ever have been. There are many .small shops and garages possessing right-hand screwing tackle, but without those for cutting threads for the opposite hand. This is justifiable as the latter are not often needed. There are occasions, however, -when. a left-hand thread is necessary, such, for example), as on the screwed ends of a brake rod on which a turnbuckle is used as a means of adjustment. It is useful to be prepared to repair or renew such a part.
"The method which I am, about to explain was divulged to me by an old marine engineer. I do not, therefore, claim it is my own idea, but it is probable that it is known to very few, and I think good purpose would be served by giving it such publicity as your columns afford.
" To screw. say, a in. bolt, left-hand thread, take a right-hand, tap haying the desired number of threads, and also a nut into which the tap is a good fit,. Cut away a portion of the nut, the cut-away part
being V-shaped, so that when in position a portion ol the tap will project into the notch then left. Reference to the sketch. [We have had this redrawn.—Enel will explain. The work to be screwed should be held between this V-notched nut and a piece of copper, the whole .a,pparatus being clamped together within the jaws of a vice. If., now, the work be turned in a lefthand direction, a. satisfactory thread will be formed. Care must be taken in positioning the tap in its nut that a cutting edge projects into the V notch. It should not, however, project too far, as otherwise there is a risk of breaking the tap.
A Broken Touring Car Axle and Its Repair.
[1747] "H.M." (West Bromwich) writes :—" We recently had a breakage in a, chassis which, although formerly a touring car, was being used for commercial work. The rear axle casing broke as indicated on the upper drawing of the two which I enclose with this letter. [We have had these redrawn and they are reproduced herewith.—En.] Spare parts being unobtainable within reasonable time, it was necessary to evolve some temporary means of patching this axle and.' making do.
"Fortunately, I had by me a piece of steel tubing of which. I thought I could make use for the job. On it I first of all welded a collar similar to that one which may be seen on the drawing of the axle, quite, close to the place where the fracture occurred. turned the end of the broken axle off square and trued its outer surface up to VE ins, diameter, plus 01000 to allow for shrinking on the tube. The tube itself was then swaged out by being heated, and having steel drifts forced up it. It was then bored to 212ins., shrunk in tilace an the axle, and the outer bearing trued up. the result was a good sound job of stronger material than that of the original axle."