Member postings for Georgineer

I used to have the ring-back code but last time I tried it, they had changed it.

One possibility nobody seems to have mentioned is to ask a friend or relation (or that nice chap from Amazon who's so concerned about unlawful activity on your account) to ring you back. If you have a mobile, you could also ring yourself from that.

Does anybody know if the old-fashioned pulse dialling, loop-disconnect, rotary dial type phones will still work?

George

A useful tool for this (which I discovered disappointingly late in life) is the "Unity Bracket", which relies on the fact that any number multiplied by 'one' remains unchanged in value. So any conversion factor or complex unit can be rearranged to equal one and then cancelled down as appropriate, and if applied rigorously the answer can be guaranteed to be in the correct units.

If we want to convert miles-per-hour to feet-per-second we can approach it thus:

I don't know off the top of my head how many feet are in a mile, so I'll do that part of the conversion in two parts:

1 mile = 1760 yards, so by manipulating the equation we get

[1mi/1760 yd] = 1, and also [1760yd/1mi] = 1.

Also 1 yard = 3 feet, so [1yd/3ft] = 1 and [3ft/1yd] = 1

And 1 hr = 3600 sec, so [1h/3600s] = 1, and [3600s/1h] = 1

Those are our unity brackets.

To convert 40 mph to ft/sec we do it with unity brackets all through, selecting the 'way up' that will enable us to cancel out the units we don't want:

40 [mi/h] = 40 [mi/h] x [1760yd/1mi] x [3ft/1yd] x [1h/3600s]

Cancelling through:

40 [mi/h] = 40 [mi/h] x [1760yd/1mi] x [3ft/1yd] x [1h/3600s]

which simplifies to (40 x 1760 x 3[ft]) /3600[sec] = 58.6 recurring [ft/sec]

As long as you know the necessary conversion factors you can then go on to convert it into metres/sec, furlongs/fortnight, parsecs/femtosecond and so on, in complete confidence that your answer will be correct (as long as you have doe your arithmetic correctly).

George

It's interesting that - unless I have missed it - nobody seems to have mentioned arithmetic, which is concerned with numbers, while mathematics is concerned with anything but. It is the proud boast of many a mathematician that they can't do artihmetic.

If you look at the Greek roots of the word Geometry, it tells you that its origins lie in measuring the Earth.

And it took me until my sixties to discover that trigonometry has to do with the properties of the trigon. What's that? Count down from, say, octagon: heptagon, hexagon, pentagon, tetragon, trigon. It's a figure with three angles.... Oh! It's a triangle!

Now I must find out about algebra.

George

That was the attitude of the lecturers visiting from the maths department when I was doing my Electrical Engineering degree. They hated us because we kept sullying their beautiful Maths with real-world applications, and even more so because we used j for the square root of -1, because,as far as we were concerned, i was already taken for current. However, I found their explanation of imaginary numbers very helpful:

First, imagine an xy graph with real-positive numbers on the right-hand of the x-axis.

If you then multiply the real-positive numbers by j you have imaginary-positive numbers. Treat j as a 90° anti-clockwise turning function, and any imaginary-positive number can be plotted on the upper half of the y-axis.

Multiply the imaginary-positive number by j (turning it through a further 90°, so you have multiplied the original number by j² = -1) and you have a real-negative number which lies on the left-hand side of the x-axis.

Complex numbers (with both real and imaginary parts) lie somewhere in the xy plane.

If my half-century-old memory serves, this is called an Argand diagram, after the French mathematician Robert Argand, who discovered (or invented) it. I am sure my old lecturers would be scandalised if they knew how useful it has been to me

George

Our local Waitrose went over to the uncoloured caps for about two weeks, and now they are all coloured again... Figure that out!

I've noticed that the caps on plastic bottles are different in different parts of the country, so there is presumably no general regulation that applies to them.

George

It's not uncommon for manuals to suggest doing things the long way round. For example, to get the Morris Minor master cylinder out (according to the Morris workshop manual), one was supposed to drop the whole offside suspension to get enough clearance to withdraw the master cylinder fixing bolts from the chassis rail.

We used to undo enough of it to get access to the torsion rod with a crowbar, then gently lever the torsion rod until the bolt could be removed. When re-assembling, the bolt was entered from the other end with the nut behind the torsion rod. Problem solved!

There's something similar on my current car, where one is supposed (according to the Haynes manual) to remove the steering wheel and half the dash to replace bulbs behind it. 'Tain't necessary!

George

If it's natural rock there are probably no regulations to meet.

When I taught Physics I was always amused by the fact that our 'official' sources had to be kept in lead-lined boxes in a locked dungeon and logged in and out, whereas the natural rocks, which were far more active, lived in a cardboard box in the prep room.

George

I had a similar experience when my old Morris Minor Estate (LTP 809G) cropped up on Car SOS, as the working example they take out and interview the owner of. I made various attempts to make contact with the present owner, but wasn't successful. Perhaps I should try again.

George

Three reasons spring to mind. First, for convenience in storing unused wheels. Second, to allow idler wheels to rotate freely. Third, it reduces the number of pins you need.

The Myford pins, though tiny, had beautifully domed ends.

George

I can't answer for the Drummond (though I have my suspicions) but the Myford used parallel pins of 3/32" silver steel. I have this in original Myford paperwork somewhere. Not Loctite - you want to be able to remove the pins, so nothing tighter than a sliding fit. .

The Myford way was to drill blind holes in the gears and collars, which trapped the pins in place. If you drill through-holes, the pin will work its way out and let go in the middle of a cut. Don't ask me how I know.

Ajax, I have used the pin drive system on my father's and then my own ML4s for over fifty years and it never caused the least problem that wasn't of my own making (see above!).

George

Backlash in itself is not harmful, and it should be routine practice always to make settings and apply feed from the same direction to eliminate it.

If the cross-slide feedscrew is only worn on some threads the feed-per-turn will vary slightly from turn to turn, so you won't get exactly 83⅓ thou for each turn. How often and how much would that matter?

Father compromised on his ML4 by putting packing between the cross-slide screw-plate and the cross-slide casting, to bring forward the less used portion of the thread. In all the years I used it I never noticed the difference, and for some years I used it to produce commercial parts.

George

Guilty as charged. Should I resign?

George

Ajax, that looks convincing for an ML4. Does your weight of 50.1 kg include the drip tray shown in the photos? I have recently lifted an ML4 (less tailstock and drip tray) from ground level to car-boot level without distress, so I would estimate it about 40 - 45kg plus those bits. Unfortunately my ML4 leaflets don't give weights, so I can't quote from source.

And before anybody asks, yes I have the manual handling and lifting certificate (and a 35-year-old disc injury) so I don't take chances!

George

Without looking it up, I think GaAs is/was used in red LEDs. I know Gallium Arsenide Phosphide (GaAsP) was.

George

Then there's bolt, as in "making a bolt for the door".

George

I once had a copy of 'The Bible in Basic English' which restricted itself to a vocabulary of a few hundred words, supposedly to make it easier for non-English speakers to understand. Unfortunately the translator had not simplified the grammar and sentence structure at all, so it was, in my opinion, as diffcult to read and comprehend as the King James version.

While on the subject of ambiguous words, the word inflammable is a rare example of a word which has largely been retired and replaced by clearer alternatives.

George

Something I've been doing since Dad taught me how to wire a plug in nineteen-sixty-... er... is that the time?

I did the same inside the film editor, for the same reasons.

George

Yes, I'm pleased to say that it did. The three-core flex was chosen to be the same diameter as the original two-core, so I was able to re-use the original anchoring arrangements.

George

I'm pleased to report back that the restoration has been successful. What took the time was getting my hands on a suitable bulb for a reasonable price. The previous owner had fitted a 12 volt car indicator bulb, which got a bit over-excited on 24 volts.

I concluded that there is no need to fit a fuse in the editor itself. I take John Doe's point that officially the fuse in the plug is there to protect the flexible cable not the equipment itself, but with a 3 amp fuse fitted in the plug it will blow long before anything else comes to any harm.

A 20-amp class 1 PAT test shows 0.03 ohm resistance (± tolerance) between metal casework and earth pin which is good, and insulation resistance between transformer windings >20 megohms, which is even gooder. My work here is done!

Thanks again to all who have contributed,

George

Sitting in my easy chair yesterday I heard a clatter in the kitchen. I went to see what had fallen off the drying rack, and instead found a tidal wave of oil advancing across the worktop towards me.

We buy olive oil in large cans and I decant it into a square glass bottle. Last time I did this, I overfilled the bottle and screwed the lid on leaving no ullage, then put it back in its accustomed place next to the combination microwave oven.

My wife was using the conventional oven setting to cook a simnel cake for Easter (yes, I'm a lucky blighter) and the side of the oven got hotter than it usually does though still not above hand-hot. The expansion due to the heat was enough to burst the bottle, and by golly, did it burst!

Naturally the oil had spread quickly and soaked into everything it could reach. So I had the joy of cleaning up a litre of olive oil laced with glass, from big shards to tiny splinters.

I shan't make that mistake again.

George