Thread: Teaching an old Dog a new Trick

I guess, like most of you, I have several charts on technical details on my bench.

I regularly use my digital vernier for converting mm to decimal inches, and refer to charts on tapping hole sizes, etc etc.
I misplaced my steel rule a few days ago and over the next day looked for it between jobs.
When I found it (right under my nose) , it was laying "face down" and for the first time, in the many years Ive owned it, I noticed engraving on the back.

Want to have a guess what it was?

20200511_161817.jpg

I had a crappy old metal rule from ebay or somewhere that you wouldn't use to draw a line from A to B but it had a similar decimal to metric chart on the back which saved the rule from the bin. Not sure where it is now though.

Ben.

Was that Rabone Chesterman.

I find rulers like these frustrating. I pick up a ruler to measure something not convert something.
The only thing worse are the ones that have measurements marked on one side and then a company name on the back. Waste of a good side of a ruler.

Tony

Hi Guys,

I have several scales like that, 6", 7" and 12". One is branded M&W.

A number of my micrometers have various conversion tables engraved on them.

The most work mine gets is to line up the parting tool on the lathe

Like other machinists I too have trouble with conversion from inches to mm and vice versa. Having done my trade 40+ years ago I am thoroughly conversant with inches, thousanths, etc. When machining, thousandths is the default I work in however I am finding that more jobs are coming in meaning there are increasing times when I need to measure in fractions of mm. Also I have a mix of machines that are calibrated in either metric, imperial or both.
To solve this constant conversion issue I made an A4 size chart on the computer using MS Excel, with mm equivalents from 0.01 - 0.09, 0.1 - 0.9 and then from 1mm, 1.5mm, ....... through to 25mm followed by 26 - 40mm. Sounds complicated but when its on a chart on the wall above the lathe its very easy to convert a metric dimension to imperial dimensions. I did try to work in metric only but it was a struggle and I reverted back to my favourite 'thous'

surely you blokes have a calculator,

Hi John, Guys,

Originally Posted by shedhappens

surely you blokes have a calculator,

Yes but old habits die hard. I was brought up on thous, 40 of them to a MM...

I've only just discovered that a tenth of a mm is virtually half a thou.

I have had a copy of this on the wall for any years. Goes from .1 to 25 mm. To go finer than .1mm I move the decimal point to the left.
It sits right next to my P & N tapping chart that I have had for about 30 years.


Drill selection chart tool mart.jpg

Tony

Next time you go to your tool supplier, ask them for the charts described above. I do that about once a year and they have usually been at no cost.

Charles

I'm of the age where through primary and early high school we used imperial. In year 10 physics and chemistry we start mainly imperial but we also learned about 2 measurement systems, MKSA (metre, kg, sec) and GCS (gram, centimetre, second). The front page of tests and exam papers contained all the conversions and it was very easy to get confused and some teachers loved nothing more than to deduct marks for a conversion stuff up.

In senior high school it was again all 3 systems as was the case at first year uni but by then we'd got used to it. It was in second year uni that imperial and CGS started to be phased out and metric became the preferred system. Younger teaching staff very quickly switched to all metric and it was only the older staff who hung into mainly the GCS system with the odd imperial reference. By the mid 1970s it was down to a couple of ancient (we they looked ancient to me but were probably only about 60) profs who still talked imperial. After that, bar a few times in the first couple of years of my working life, it was all MKSA.

Anyway, all this means I am fluent in all three systems and I find it useful to be able to talk/write/calculate in imperial when talking to yanks in the saw milling forum. All the scientists I've worked with from the USuff., especially the younger ones, talk metric about work but switch to imperial for day to day stuff.

It's weird that I still prefer imperial for a few things, like gas flow (CFM) and Linear gas flow (FPM).