An interesting co-incidence of units

[Mike PooleParticipant @mikepoole82104]

Funnily enough I too have a Rabone Chesterman No33 conversion rule, it has mm to 1/32" on one side and mm to 1/20" on the other, an interesting item but I don't use it everyday, I also have a Shardlow metric and imperial mic, not the easiest thing to use, I bought it as a curiosity. There is an advert for the No33 on eBay £2.99 and 99p post at this minute.

Mike

Edited By Mike Poole on 30/01/2017 21:13:51

Edited By Mike Poole on 30/01/2017 21:15:49

[John Stevenson 1Participant @johnstevenson1]

This is my favorite rule.

I cannot get on with the 1/2mm divisions as they clutter the rule up too much and you can easily split a division by eye if you don't have the clutter.

I also like the same scale top and bottom as sometimes you are taking a measurement from the top of a part and other times from the bottom all all too often to save real estate they will give you a different scale when all you want is to work how you want to.

This increasing – decreasing division layout was devised by M&W as being the most pleasing and easy to read.

The problem is with wanting a M&R layout, same scales top and bottom and no 1/2millimeters is that no one makes one so I had to laser engrave my own.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Mike Poole on 30/01/2017 21:08:28:

There is an advert for the No33 on eBay £2.99 and 99p post at this minute.

.

Thanks, Mike … That's the same seller as I mentioned earlier

… He must have found another box of them !!

MichaelG.

[John ReeseParticipant @johnreese12848]

Let me guess….

Most of those who posted are retires and have WAY too much time on their hands.

[Anonymous]

In ordinary mathematics there are two infinities – countable and uncountable.

Andrew

[John HaineParticipant @johnhaine32865]

Posted by John Stevenson on 30/01/2017 21:46:25:

This is my favorite rule.

I cannot get on with the 1/2mm divisions as they clutter the rule up too much and you can easily split a division by eye if you don't have the clutter.

I also like the same scale top and bottom as sometimes you are taking a measurement from the top of a part and other times from the bottom all all too often to save real estate they will give you a different scale when all you want is to work how you want to.

This increasing – decreasing division layout was devised by M&W as being the most pleasing and easy to read.

The problem is with wanting a M&R layout, same scales top and bottom and no 1/2millimeters is that no one makes one so I had to laser engrave my own.

I've wanted a rule like that sine I saw them described in New Scientist when I was a teenager! I think actually the layout was designed at NPL for easy reading, but never really became popular.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by John Haine on 31/01/2017 07:19:01:

I've wanted a rule like that sine I saw them described in New Scientist when I was a teenager! I think actually the layout was designed at NPL for easy reading, but never really became popular.

.

The aforemebtioned Rabone No.33 uses that layout for the millimetre scale.

"though of course it loses the 'same both edge' feature favoued by JS.

https://goo.gl/images/VcsnQy **LINK**

MichaelG.

[Martin KyteParticipant @martinkyte99762]

pgk pgk

|My Granddaughter used to count: One, two, three, lots..

As to specifically how many infinities then I suppose one starts by counting how many sets of parallel lines meet each other.|

Consider the infinite series the sum of all the integers and the infinite series the sum of all the even integers. The even integer series can be obtained by multiplying the integer series by 2 so now we have two definitions of infinity one of which is twice the other.

:0)

Martin

[Clive IndiaParticipant @cliveindia]

Posted by John Stevenson on 30/01/2017 21:46:25:

….I cannot get on with the 1/2mm divisions as they clutter the rule up too much and you can easily split a division by eye if you don't have the clutter.

Yes, I find that too. Could it be an age thing? No point bothering as we cannot change that?
So often the other side of the rule is left blank – what a waste!

Having recently mentally binned cms and now exclusively using mm I find I make less mistakes in metric.

In the process I binned the rules which did not comply. The new ones are Rabone and I find them really good. They are metric one side and imperial the other, which suits me – some might want both on one side to compare but I just measure twice if needs be. The metric side is all mm, one edge in 1mm steps, the other in 0.5mm steps. There is plenty of cheap tat around at 90% less than Rabone but I, at least, can see the difference and the format works for me.

Just me. Thank you Michael G for starting this off – you got some stick but I found it interesting.

[roy entwistleParticipant @royentwistle24699]

I,ll second Clives remarks re Micheal G. Well done Micheal keep them coming, allways interesting

Thanks Roy

[Neil WyattModerator @neilwyatt]

Juggling 2' and 3' rules today, I think they should read left to right on one side and right to left on the other.

Neil

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Neil Wyatt on 31/01/2017 17:02:43:

Juggling 2' and 3' rules today, I think they should read left to right on one side and right to left on the other.

Neil

.

+1 for that

'though I do have a rather neat one [from Aldi, I think] that has plastic sliders on an Aluminium extrusion, and reads both directions, from the middle.

MichaelG.

[Tim StevensParticipant @timstevens64731]

Look chaps, its quite easy and very practical.

If you want to use a metric lathe to cut a whitworth thread, all you need is a pair of gears. One with thirty one and three quarters teeth, and one with one and a quarter teeth.

I would have thought that was really obvious.

But it is really handy, too, to know that a 19mm spanner will fit a 3/4 AF nut.

Cheers, Tim

Edited By Tim Stevens on 31/01/2017 18:05:24

[John Stevenson 1Participant @johnstevenson1]

You mean like this Neil ?

[JasonBModerator @jasonb]

I would have thought there is quite a risk when using the right to left rule of getting the dimension wrong. We are so used to reading from left to right that the brain is likely to make you read the size of a part that is 113mm as 127mm eg 7mm to the wrong side of 120mm.

All my rules and tapes will read right to left. Just the numbers are upside down which I don't have a problem with. They will also read top to bottom and bottom to top

Edited By JasonB on 31/01/2017 18:36:43

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Tim Stevens on 31/01/2017 18:04:58:

If you want to use a metric lathe to cut a whitworth thread, all you need is a pair of gears. One with thirty one and three quarters teeth, and one with one and a quarter teeth.

I would have thought that was really obvious.

.

Thanks for that enlightenment, Tim

Having put aside all thoughts of integers, I can see that you might be on to something.

[or do I mean on something ?]

MichaelG.

[John ReeseParticipant @johnreese12848]

I have a wooden ruler from the Buffalo New York School District that is marked in full inches only. No need to mess with those finicky little lines like on other rules.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by John Reese on 31/01/2017 19:07:47:

I have a wooden ruler from the Buffalo New York School District that is marked in full inches only. No need to mess with those finicky little lines like on other rules.

.

John,

It's good to see you participating in this thread, instead of just making witty criticisms.

Your previous post has already been used in evidence against me

… by none other than John Stevenson **LINK**

http://www.model-engineer.co.uk/forums/postings.asp?th=124432&p=1

MichaelG.

[John Stevenson 1Participant @johnstevenson1]

Where were you mentioned Michael ?

Certainly not my me

[Andy AshParticipant @andyash24902]

When I'm thinking about metric and imperial, and I have no calculator, I usually stumble across the memory that 1/128 is very close to being 0.2mm.

What I find interesting, is that 0.2mm x 128 is 25.6 (a naughty metric inch) but then that 25.6 x 5 is exactly 128 again.

Obviously that's a millimetre out.

Had it not been for the physicists they might have got metric right.

Edited By Andy Ash on 31/01/2017 23:03:09

[Michael GilliganParticipant @michaelgilligan61133]

Posted by John Stevenson on 31/01/2017 21:37:45:

Where were you mentioned Michael ?

Certainly not my me

.

Post 3 and the opening of Post 5, in the other thread …

**LINK**

http://www.model-engineer.co.uk/forums/postings.asp?th=124432&p=1

… combined, are pretty obviously pointed at me.

MichaelG.

[Author]

Posts