• WAYS AND MEANS.
Page 65
If you've noticed an error in this article please click here to report it so we can fix it.
Interesting Contributions from Our Driver and Mechanic Readers.
The Lubrication of Brake and Steering Joints.
r1011111ENTS have appeared in this page at various times regarding the lubrication (or, shall we say, lack of it) of the joints of steering rods, rods for operating brakes and gear selectors. A correspondent, " R.T.C.," of Colne, Lancashire, calls attention to this fact, and sends what appears to he a very simple and practical suggestion.
He points out that such joints as these are exposed to the ravages of grit, wet and dust in a long day's run, which makes the proper lubrication of these parts difficult and is the cause of much neglect. Unfortunately, the designers of commercial vehicles seem to • have given very little attention to providing a proper means • whereby such parts can be kept reasonably well lubricated.
" R.T.C." tells us that about 14 months ago he completely rebuilt a 3-ton vehicle, and tried an experiment with the lubrication of the joints which he has found to give very satisfactory results. In each of the forked members of the joints he fitted a pad of thick felt, as shown in his sketch, cut so that part of it occupied the hole in the rod, preventing it from falling out. These pads he soaked well in engine oil, and having filed a groove in the face of the boss of the lever, the oil could get to the bearing of the pin. He tells us that any oil poured on the pads is filtered before it reaches the pin, also that the movement of the rod acts to squeeze the oil out of the pad and to keep the pin lubricated.
A Worm-driven Screwdriver for Close Work.
THE usual bent-end screwdriver is slow, difficult to handle, and only a makeshift at the best
In contrast to this, the tool shown in the attached sketch, which was devised by a clever mechanic from a screwdt4iVer and a small worm and wheel, and sent to us by " G.A.L.," of Washington, U.S.A., is a good practical idea, resulting in saving time and trouble in assembling screws which have to be dealt with in awkward situations.
The sketch is self-explanatory. The body can be made from a piece of brass or steel, sufficient area being provided at the back to allow of firm pressure from the hand, as it is of little use providing a drive unless the end of the screwdriver can be kept in the slots of the screws. In use the screw is turned readily by the handle, and in the final tightening the worm drive gives a powerful turn, which will seat it
solidly. _
To Remove Gudgeon Pins.
THE removal of an obstinate gud geon pin is often a very troublesome job, as one cannot use great force in driving it out owing to the fragile nature of the piston. Any attempt to place the piston on an anvil while the pin is being driven will often result in breaking the piston.
A very practical suggestion is sent
us by " A.W.," of Wolverhampton, who recommends the use of a small block of metal with a tapped hole in it to take a setscrew with a point so formed that it will bear on the end of the gudgeon pin. The old push-bicycle chains are joined up as shown and placed around the piston and the piece of tapped metal, taking care that the chains do not bear against the end of the gudgeon pin.
Considerable pressure can be brought to bear against the end of the pin in this manner, as the chains, being flexible, will distribute the stress and
are not likely to break the piqon. Should no tap be handy, a clearance hole can be drilled and an ordinary nut placed under the piece of metal.
A Useful Lathe Tip.
MANI drivers have at times to do
small turning jobs in lathes, and not being often highly skilled in the art of turning they sometimes make what is called a "bloomer " by turning slightly too small some part that should be a tight fit in a hole, so that instead of being a driving fit it is an easy one, as a matter of a few thousandths of an inch will make all the difference.
One of our readers, " A.G.," of Glasgow, suggests that when such a thing happens it is not always necessary to throw away the part that has been turned too small, as a coating of solder will add the necessary .001 in. or .002 in. required for a driving fit. Any extra solder will be scraped off by the edge of the hole while the part is being driven in.
• How to Fit a Bush.
A PRACTICAL correspondent, " 0.L.," of Islington, sends us the followiug tip, which may be useful to mechanics who are not specialists in lathe work:—
When fitting a new bush to a hole in order to replace one that has become worn, the usual practice is to bore the new bush to the required diameter, then drive an arbor or mandrel into it and turn the outside to fit the hole into which it has to go..
Now, this is all very well in a way, but a turner of small experience often meets with an unpleasant surprise when he removes the bush from the arbor and finds it too slack in its hole, which often results from the arbor having expanded the bush, because bronze metals are elastic and will expand under force and then contract again.
In order to avoid the calamity of the bush being found to be too small when it has been removed from the arbor, it is best to proceed as follows: When the bush is on the arbor and driven tight enough to stand turning, it should be left so that it is too large to enter its hole, and to obtain this dimension a simple way is to use the old bush as a guide and set the calipers the thickness of a post card larger. This would be about eleven thousandths of an inch if measured with a micrometer, supposing one to be available.
The bush should then be removed from the arbor so that it will shrink back to its normal size, and then be tried in its hole. The best way to do this is to drive it in with a mallet or piece of hard wood and a hammer ; then, if the bush will not go into the hole, it should be put back on the arbor, tapped on lightly so that it will just stand filing, and gone over with a ffie, taken off and tried again in the hole, and this should be repeated until it will just drive home.
On no account should the bush be driven into the hole while the arbor is in it, for the latter may expand it.