Drivers and Mechanics.
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A Home-made Generator.
The sender of the following communication has been awarded the .z0s. prize this week.
[1158] " W.H." (Axminster) writes :—" I send you particulars of a home-made acetylene generator and lamp which has now undergone a long test. Any driver who can use a soldering iron can make up this appliance. The one that 1 have myself cost very little to make, as it is composed of two oil tins, one being fitted with an adjustable needle valve, which is made from a piece of in. round iron. The socket for the valve is soldered on to the bottom of the water compartment.
"The adjustment is obtained by the .1 in. rod being wrewed for about 1 in. of its length, and an adjusting nut is soldered on to the top of the cover of the water vessel. A second loose nut is fitted in order to lock the adjustment. The lamp was an old hand light which I had carried on my lorry for some little time. To prepare it for use as an acetylene lamp, all that is necessary is to solder a bridge piece of tubing to carry the burner. A piece of flexible tubing com pletes the outfit. Perhaps sonic of your readers, whose employers are not inclined to go to the expense of a new and expensive headlamp, will care to make up the lamp described here themselves ? Of course, drivers, who wish something more elaborate than the appliance here described, may be inclined to spend a little money on the fittings."
Further Notes on Lapping Cylinders.
[1159] " R.T," (Andover) writes:—' I read with interest the letter on lapping out worn cylinders as described by 'G.W.' (Dartford). [Our correspondent refers to letter 1150 in our issue dated 24th October.] While agreeing in part with your Editorial footnote, which stated that the practice has
fallen somewhat into disuse, I still think that, under certain conditions, the method has much to recommend it.
"Whenever I have an engine down for overhaul, I always do a little grinding in of the rings in this way, and have found it a, very satisfactory process. If loss of compression is indicated by brown patchesupon the rings, I carefully expand them by tapping them on the inside with the ball of a small hammer, and then, after filing them on the outside to fit nicely into the cylinder, I grind them in on the piston with a specially made wooden connecting rod..
When this job is done by hand, it is advisable to place a small block of wood in the top of the cylinder. This will prevent the piston being pushed too far up into the cylinder, in which case the top ring may spring open in the combustion chamber, and so make a great amount of work and trouble to get it out again. "Some time ago I made up A. stout angle-plate and bolted it in position on to a machine-saw, and then secured the cylinders to this plate. I next fixed my wooden connecting rod to the crank which operated the saw-frame, and, while I was engaged in scraping the bearings, etc., of the engine, my assistant was engaged in lapping the cylinders. I was, of course, careful to place the piston in the cylinder in the same position in which it had been working previously. "Sometimes it is well to skim the Pistons and to fit thicker rings before lapping them gastight." Repairing a Fibre Wheel.
[1160] ".A.H.H." (Cardiff) writes :•-" I forward to you particulars and sketch of a repair recently carried out to a fibre timing-wheel. Owing to a small screw getting in mesh when the wheel was running, four of the teeth were stripped. I was asked to -effect a repair if it was at all possible, and proceeded in the following manner :— "I obtained a niece of solid fibre 1 in. square, and I then cut out on the wheel a dove-tailed section as shown in the left-hand view, and filed the fibre so that it would knock into place rather tightly. I then made up a template from the remaining good teeth, and marked off the required teeth on the inserted 'block, cutting out and finishing off with a hack saw and file. When this was done, I turned up two cir-eular brass plates and placed them in position, and held them together with six rivets. This made a firm and satisfactory job at little cost, and the wheel is running as well now as when first built into a new • engine."
Cornish Watering Places.
[1161] " W.H." (Axminster) writes:—" I recently -carried out a journey into Cornwall, from Axminster, with one of the over-type Mann steam wagons, and thought that an account of the trip would be of interest to the CM.' The wagon is two years old, and has done a good mileage to date without giving any trouble. The load to be taken into Cornwall eon-sisted of furniture, and weighed eight tons.
" I was a little anxious as to whether the wagon would do this work, especially up some of the had -hills that abound in Devon and Cornwall. Generally my load consists of flour, but this trip taught me that five tons of flour takes as much shifting as eight tons of furniture.
"The first. stop was at Honiton. A good supply of water is to be obtained here from a stream -that crosses the road at the lower end of the town. Adjoining the watering place is a coal merchant's where Welsh steam coal can be obtained. Here also is a good pull in, and accommodation is provided for wagon and driver at the Lamb Inn,
'The main road to Exeter was followed further ; we called at Honiton Clyst, 12 miles from Honiton, where more water is to be obtained from the river running by the roadside. Exeter was the next call, and then on to Okehampton. This road is a gradual rise all the way, but there are no very bad hills to climb, the going, however, being, as the horse-driver says, 'all against the collar.' The next watering pince is at the Traveller's Rest, a wayside inn five miles from Exeter, The route then lay to Whiddon Down, and then on to Hicklepath. In this latter town are several places where accommodation is provided for steam and petrol wagons and drivers. Okehampton was the next call.
" In the morning we obtained a supply of good • quality Welsh steam coal at Is. 4d. per ewt. At the Okeharupton market place a lorry can be pulled in and left for the night on payment of is. This town saw the end of the first day's run, 51 miles, which, considering that this time included the loading of the lorry, I did not think was at all bad. " In the morning we filled up from the river close to the market place, ran an eye quickly over the engine, oiled up, and filled the grease cups. At eight o'clock prompt we started from Okehampton.
" The last five miles to Launceston was a very steep pull, with the road soft in places_ The next watering place is 10 miles farther on, at Laneast. We then returned to Launceston, and started off very early the next morning; _arriving at Axminster about 11 p.m., having done the trip in three days, including loading and unloading the vans.
" This account of wayside facilities may interest others. Perhaps, for the benefit of us all, they will send in accounts such as this, for I am sure many drivers will appreciate a little knowledge of country that is strange to them where water, food, coal and lodgings can be obtained.
';fltr%ildil interest you to know that the journey was performed without mechanical trouble of any kind whatsoever. Most of the time we ran on top speed, and it was not necessary to convert the engine to simple cylinders at any part of the trip."
When Slitting Piston Rings.
f1162] "RMS." (Luton) writes :--" I recently had a large number of piston rings to split and fit, and I made up a simple jig for this job, of which I send you a rough sketch. [We have had this re-drawn.--En.] "I got, out of the stores, a piece of kin, iron plate, which was a little larger both ways than the outside diameter of the piston rings. I bent the top over at right angles, making a ledge about 1 in. wide. I then fitted to the face of the plate four cheese-headed setscrews, which were screwed right through the plate only, leaving only the heads projecting. The insides of these screw heads were then filed flat, until the rings clicked in tightly between them with a little pressure. I then slotted the top of the jig as shown. When in use, the thinnest part of the ring is at the top, and the slots are cut with a hack saw. This ensures the correct slitting of the rings without trouble. When in use, the whole affair is gripped in the vice, and the saw run down the slots. If these are placed the right distance apart, exactly the right amount of the ring is sawn out."