How important are ...

Depends. If the frame/bogie is made of styrene, then IMO metal axle bearings are essential. Styrene wears away pretty quickly. If they are made of a nylon-type plastic, then they aren't needed, but put 'em in if it makes you feel better. For lubrication, I twirl a sharpened B6 pencil in the bearing. B6 is practically pure graphite.

HTH Wolf K.

Visions of starting the A level maths course in 1967; we were advised to lubricate the slide in our slide rule by running a soft pencil along the "tenon" of the slide, being more feasible than along the "mortise" of the main body.

(Slide rule still in occasional use today when the battery's gone flat in the calculator - British Thornton model No P271)

Not sure if theyre nylon or styrene, but decided Wolf was correct, feel better with metal ones.Ream out plastic holes till bearing just fits, plastic splits, cut it off and just have metal bearing. 30 mins to do first one, 3 minutes for the rest :-) Runs nicely.

Cheers, Simon

Was that the double sided one, I never did work out what all the scales were for. Did me through university though.

Gordon.

Sounds like you had a log-log one then - the scales of which are for calculating non-integral powers, such as 2.5^1.5 or 3.6^2.35.

Still have a couple lying around somewhere.

David

Being duly cautious not to drill right through any plastic, because the moulded plastic replica looks better than with a lump of metal poking through.

# Was that the double sided one, I never did work out what all the # scales were for. Did me through university though.

No, single sided.

Lost the instruction leaflet fairly early on, so still cannot fathom out the ISD and ITD scales. ("Inverse Sine Differential"?)

Was ok with Ratio kit as metal top hat bearing replaced similar shaped moulded plastic one. Axle box then goes over top of new bearing - after minor reaming. Did 24 all together and no problem after first on.

Cheers, Simon

I still have my 1962 Faber-Castell slide rule, as well as my 1955 Knott's Four-Figure Mathematical Tables. Neither sees the light of day, except when I pull them out like I did just now.

One of the curios I picked up (I definitely wasn't in school 130 years ago!) is a copy of the 6-figure, "Nautical, Logarithmic and Astronomical Tables" pub 1878, the first owner seeming to have pencilled his name in 1883.

Like your tables, it never sees the light of day unless stimulated by an off-topic post!

Everey now and then I clean out the desk in the spare bedroom, and come across my old slide rules, two of them, both K&E. I hesitate, then put 'em in the drawer....

Wolf K.

Recon mines quite modern then Jakar (didnt realise they'd been going that long), probably bought in early 70's.

Cheers, Simon

I just quickly laid my hands on my Aristo 0903 slide rule which dates from... ...1970. I had to sit both O-Level and CSE maths, and in one we were allowed to use calculators and in the other we weren't - can't remember which way round it was - but a little quirk said that you could use a slide rule where you couldn't use a calculator. The teacher supervising the exam had to go and check the rules before allowing the exam to start!

I'm looking at it now and wondering what all those lines and numbers are for :-)

Slide-rules are great when redrawing scale drawings to a different scale. Instead of many entries into a calculator resulting in numbers like

13.174974321mm one just sets the slide rule scales once and reads of the nearest full or half millimeter.

Regards, Greg.P. NZ

I went to school a couple of years before then - even the school couldn't afford a calculator in those days.

I wasn't sitting the exams in 1970! (June/July 1982 according to the certificate)

My final school exams 1967.

1970: I was a production planner in a fashion knitware factory. Six of us, all working with huge numbers of figures all day and the firm owned ONE calculator. At stock-take time we had a mechanical machine (I forget the name) and an elderly lady who had been Miss Canada 1928* and data operator for the forgotten firm after that, used to come out of retirement to operate it.

(*don't quote mee on the year)

Greg.P. NZ

Possibly a comptometer. I remember our local distillery office having several of them in their accounts department. I would imagine that they did require quite an experienced operator - IIRC multiplication was done by successive addition by decimal place. I can't remember how they did division :-)

I suspect that the operators might have suffered from RSI in a big way but I don't think we called it that in those days :-)

Jim.

They did division by successive subtraction by decimal places!

In the hand-crank calculators we used at university in the early 60s, you would crank backwards until a bell rang, then shift the decimal place and crank forwards until it rang again, and so on.