Metric to imperial

My mental arithmetic is getting a bit rusty as the "old timers disease" is starting to set in and to do some of the maths above I would be reaching for a calculator.

But in the original post it stated::- " I work with metric drawings but my stumbling block is knowing quickly how much cut is needed to get to size without reaching for the calculator."

If converting dimensions from metric to imperial (and vice versa), I find it is much easier to convert them all and mark-up the drawings before you start machining instead of doing it while machining.  The actual converted dimension that you are using is recorded and can be used when measuring and checking the finished part.

Paul

Edited By Paul Lousick on 06/01/2021 10:47:40

I know, but the thread appeared to started by a mathematically challenged member who is unlikely to be doing mental arithmetic.🙂 KISS Principle in operation. The solution I presented, in simple form, works for any denominator one might come across so is a universal, not specific, solution.

The OP asked a specific question

The OP's specific question seems to be at odds with the thread title.

Where's the imperial?

Many metric lathes calibrate the X slide dial in diameter not radius...

It would be interesting to know what if any different lengths the division lines are and what if any numbers are on the handwheel as that may make it very easy to put on say a 0.3 cut if every 4th div is marked/longer and then it's just 2 and a bit divisions for the remainder.

Also what is the leadscrew pitch 2mm, 2.5mm or something else.

Or it may be better to treat each div as 0.05mm and work in diameter rather than radius

So does my imperial lathe.

Andrew

Hi, well I just do it the easy way, I use a calculator and I'm not ashamed to say so.

Regards Nick.

Sorreee, should have said ‘a universal, not just a specific, solution‘

Perhaps that would have kept you quiet, S?

.

I will be quiet after I have written this:

Your answer simply did not address the question ... which, for convenience, I am quoting here with emboldening of the significant points which you appear to have overlooked

[quote]

Hi all

I have a Denford Viceroy with metric leadscrews and graduations of 0.025.

I work with metric drawings but my stumbling block is knowing quickly how much cut is needed to get to size without reaching for the calculator.

For instance, say there is 0.73mm to come off halve it 0.365 (thats the easy bit) how do you know quickly how many 0.025's there are in it.

Regards

[/quote]

Telling a man who has asked that perfectly reasonable question to divide the number by 0.025 is, in my opinion, both patronising and crass.

MichaelG.

If you have a digital caliper to hand, it makes conversion easy.