I was not an apprentice, though I did take a 1 quarter machine shop class in high school, in 1973. Only place I've ever seen a mil used as measurement in thousandths of an inch is in sheet plastic. 4-mil is used in trash bags, and as a temporary drop cloth to protect floors when painting, for example. Thicker material is used for temporary shelter for delicate plants in gardening, too. Looked it up, got a definition that phrased it as "still used in the US" so I'm guessing it been in use for some time.?

?

It's also used for angular measurement. Maybe because we English speakers like our words to have many possible meanings? :)?

?

Bill in OKC

?

William R. Meyers, MSgt, USAF(Ret.)

?

?

A human being should be able to change a diaper, plan an invasion,
butcher a hog, conn a ship, design a building, write a sonnet, balance
accounts, build a wall, set a bone, comfort the dying, take orders,
give orders, cooperate, act alone, solve equations, analyze a new
problem, pitch manure, program a computer, cook a tasty meal, fight
efficiently, die gallantly. Specialization is for insects.
LAZARUS LONG (Robert A. Heinlein)

?

?

?

On Friday, September 25, 2020, 04:55:06 AM CDT, Richard <edelec@...> wrote:

?

?

When I was an apprentice many years ago in the UK we worked with

imperial measurements. An inch was 1.000" a tenth was 0.100", one

hundredth was .010", a thou' was 0.001", and a tenth of a thou was 0.0001".

I now see our American friends refer to 0.001" as a mil.

When did this start and why does the thou' seem to be out of fashion.

Given the use of metric measurements on both sides of the pond is the

use of mil not likely to cause confusion with the millimetre? Typically

over here (as far as I am concerned) a tenth of a mil is 0.1mm not 0.0001"

?

Richard

?

?

?

?

?

?

Mil is a shortened version of ‘mille’ Latin or French for thousand (despite what Wikipedia says it is not English for thousand.)

While I don’t ?have enormous amounts of amchine shop experience, I’ve only ever heard it in reference to plastic film or paper thickness.

On Sep 25, 2020, at 6:00 AM, Richard <edelec@...> wrote:

The use of mil is maybe just an American thing then as I certainly never came across it in the UK when we were imperial.
Richard

On 25/09/2020 12:56, CLevinski wrote:

Hi, Richard,

With respect, and just FYI... even 65 years ago, my father commonly referred to 0.001 inches as a "mil". I was surprised a few years ago when John Lindo used it in reference to metric measurements, and I had to ask him exactly what he meant.

The Merriam-Webster dictionary defines a "mil" as follows:

Definition of?mil

?(Entry 1 of 3)

1:?found a salinity of 38.4 per?mil

2:?a monetary unit formerly used in Cyprus equal to ?/???? pound

3:?a unit of length equal to ?/???? inch used especially in measuring thickness (as of plastic films)

4:?a unit of angular measurement equal to ?/???? of 360 degrees and used especially in artillery

In order to avoid confusion, its use should probably be avoided entirely where both metric and Imperial measurements are used..

--
Regards,

Charlie
New Jersey, USA

?

ANTHONY’S LAW OF THE WORKSHOP: Any tool, when dropped, will roll into the least accessible corner of the workshop.

?

THE LINDO COROLLARY: If you have cats, they will promptly hide the tool.

--?

Bruce Johnson

"Wherever you go, there you are." B. Banzai, PhD

Hi, Richard,

With respect, and just FYI... even 65 years ago, my father commonly referred to 0.001 inches as a "mil". I was surprised a few years ago when John Lindo used it in reference to metric measurements, and I had to ask him exactly what he meant.

The Merriam-Webster dictionary defines a "mil" as follows:

Definition of?mil

?(Entry 1 of 3)

1:?found a salinity of 38.4 per?mil

2:?a monetary unit formerly used in Cyprus equal to ?/???? pound

3:?a unit of length equal to ?/???? inch used especially in measuring thickness (as of plastic films)

4:?a unit of angular measurement equal to ?/???? of 360 degrees and used especially in artillery

In order to avoid confusion, its use should probably be avoided entirely where both metric and Imperial measurements are used..

--
Regards,

Charlie
New Jersey, USA

?

ANTHONY’S LAW OF THE WORKSHOP: Any tool, when dropped, will roll into the least accessible corner of the workshop.

?

THE LINDO COROLLARY: If you have cats, they will promptly hide the tool.

Interesting thanks, I only bought the motor because of the sale.

I "plan" on having travel stops, but do not know how to get my spindle to fast stop.

I use the and there is very little known about the controller.

I am currently?using a 10 k pot in place of the Hall Effect foot pedal and when I turn the pot down there appears that there might be braking

involved. If I just turn the power off the motor continues to? rotate.

Ralph

On Thu, Sep 24, 2020 at 7:26 AM Bob T <zs6bxi@...> wrote:

Ralph 12 Nm is a beast if you run it at its rated current. I have one on my mill and managed to shear a drive key using the stepper at full rated current. Fortunately the stepper drive has lower current settings.....its on about half rated current now.
Don’t (how do I know ? ) use it at full current with out a trip switch to prevent end stop crashes.

By the way with Lindo’s corollary.....tools are not the only things cats make off with ! interesting curls of steel and aluminium also walk too. And they end up in funny and not so funny places....a freshly made bed ?
And of course O’flanagan held that Murphy was an optimist.

Regards ?Bob

--
Clausing 8520, Craftsman 12x36 Lathe, 4x12 mini lathe, 14" Delta drill press, 40 watt laser, Consew brushless DC motors and a non working 3D printer

Richard have you released your RPM code?
I'd really like some dependable RPM code of which I knew the author.
I will be adding to it as I also need to use a DS1803 digital potentiometer for spindle speed control.
Had you said you were using a Teensy?
My encoder has a X port, a single pulse per rev.

Ralph
--
Clausing 8520, Craftsman 12x36 Lathe, 4x12 mini lathe, 14" Delta drill press, 40 watt laser, Consew brushless DC motors and a non working 3D printer