So one thing that's important to to know about and also to set up in your software at the start before
you even start drawing anything.
It's important you set up the units and you know the units you want to work with.
So most people will know the type of units they want to work with, but you do need to set that up at
the start.
Otherwise, it can it can really mess things up.
So the main two things and differences between the metric system and the imperial system in the US still
use the imperial system feet and inches.
Most other places use a metric system these days, but even then you need to kind of narrow down how
you're going to work within those systems.
So let's just have a look and and see exactly what I mean.
So you may be working in metric system, but if you were to create a small, um, a component, say.
Then you're probably going to be working in millimeters.
Same if even if you do building layouts, a lot of these days, people will work in millimeters.
In the UK, it tends to all be in millimeters until you get to the really big distances.
I've seen people use centimeters a lot in Europe, but on the big layouts, if you were doing something
like a site layout with lots of buildings and it was maybe a few miles wide, you probably wouldn't
use millimeters.
In that case you'd use meters.
Okay, But you need to be aware of what you're using.
You don't want to be putting dimensions on and measurements and not knowing what you're getting.
If you're getting a measurement of 500, you need to know what that is because obviously 500mm is a
big difference in 500m.
And likewise in the US, if you're using feet and inches for a larger, say, a building layout, it
may just be inches.
Using for small components probably would be.
So you might and you might be down to fractions of an inch.
So whereas a building layout would be maybe ten feet six inches for a small component, you might be
working in 30s of an inch.
So you know, you might have a measurement that's two and ten 30s and then you're in fractions or sometimes
it's in decimals of an inch.
So instead of saying half an inch, it's 0.5.
So even with inches, you can have different ways of expressing it decimal or fractional and it's important
to know.
What it is you want to use and to set that up right from the beginning.
Now, generally you will know.
In terms of working in metric or imperial, it probably is down to where you're based, although sometimes
you could be based in Europe and working on a project in America or vice versa.
And then you might be using a type of unit that's a bit more unfamiliar, but generally you'll know
that at the start.
So first thing you want to do is set those units and we'll have a look at doing that now.
In AutoCAD.
The basic measurement is just a unit.
Okay.
So this is something to kind of get your head around at the start.
AutoCAD works in units.
If you create something that's ten units long to AutoCAD, it is ten units long.
Now.
You could call that what you want.
You could call it millimetres, you could call it inches, whatever.
But it is still a unit.
You're just saying to AutoCAD, okay, in this drawing, every unit represents one millimeter or every
unit represents an inch.
Okay, so let's have a look at changing those.
So in AutoCAD, you can just type in units, press enter, and you will get the drawing unit setting
box.
So this box here, the first setting is architectural.
Okay?
And you'll see this is inches and it says inches here for the insertion scale.
So content that's inserted in the drawing will be in inches and you can set your precision.
So are you working down to a precision of half an inch, quarter of an inch, maybe 256 of an inch,
which I'd say is very precise for an architectural drawing.
You've also got decimals.
So do you prefer to work in degrees minutes and seconds or just decimal degrees, 45 degrees?
ET cetera.
And again, how precise do you want to be with that?
Now you can go decimal.
So even in inches.
You can be decimal.
Okay.
So if I.
Okay that so if we were, let's say we were 10.5in.
Okay, if I just click on the line here and left click, then I can drag this out and I can type in
our length.
So if I were to say 10.5 and then right click to enter, if I click this now, and if you haven't got
this box, you can right click and go to properties, okay?
And you'll see it says 11.
So I drew this at 10.5, but it says it's 11.
Well, let's have a look.
We've got our precision set to zero if I did it to one decimal point.
And now click on it.
You can see it says 10.5.
So by setting your default units, you can set.
How many of these decimal places is going to come to?
And sometimes you open a drawing because a lot of people don't change that precision setting.
By the way, I don't know why, but sometimes you'll open a drawing and you put a dimension on and it
comes out and it will come out at 10.50000.
That's just because they haven't changed the units scale.
Okay.
So if you if you see that, it's easy to stop that happening every time just by changing the precision
in the units box.
Okay.
So I'm going to leave that there.
But we're on decimal and we're on inches.
So that's how we would express inches.
We can also go engineering.
So let's look set to engineering.
If we click this line again, you will see now it's 10.5 and it has the inches symbol.
We've got our area in square inches, okay?
Everything is actually denoted as being in inches rather than just a decimal.
It's actually saying inches.
We can go units again and we can go to oops, we can go to fractional.
So under fractional this will be ten and a half and it actually says that the fraction a half.
So sometimes when you're drawing and you have an old drawing, it might say it's so many sixteenths
of an inch and you have to if you're in decimal, you go on your calculator and you work that out or
you have a conversion sheet of what that is as a decimal.
But you can, if you want, just have the unit set to this and you can you can draw that.
So if it was.
I'm going to say this is one.
And 5/16 of an inch.
So how you would write that is one and then do the dash.
So it's one complete inch and then next is five and then do your um.
Slash 16.
Okay, so that is one and 5/16 of an inch.
And now when you press enter, if we click on that.
Okay.
So what's happened now?
It says one and a half.
Why is that?
It's supposed to be one and 5/16.
Well, remember, we've got our precision set, so AutoCAD will always.
We'll always kind of round things up because we've got our precision set to half an inch.
That's how it's going to be.
We we wrote 5/16, so we need to be on a precision of sixteenths.
Okay.
And now we will see.
It says one and 5/16.
So make sure your precision is set to to what you want to be.
Usually in a drawing you will have a mixture, but if you just set it to your highest.
Okay, So if you're if you have one dimension that's in 30s, just set it to that.
But if we look now, if we look at this blue box, you'll see it's still saying the distance in inches.
Even though we're going into feet because we're over 12, it's still calling it 51in.
And that's where these other settings come in.
So, for instance, let's type in units if I change it to architectural.
Architectural, you're using bigger distances.
If you think of architectural, think of working in feet because you're talking about building layouts.
Now, if I was to draw a line in the blue box, you'll see it says three feet, and the way it's shown
it is free.
And then the foot sign, dash free space, half inch.
So that is three feet and 3.5in.
Okay.
And you can see we've got a precision precision set on 16 by the look of it, because it is showing
if we move it along, it's going into sixteenths fractions.
And I can write.
And if you wanted to type that in, you could put so let's say it wanted to be six feet.
So we do our six feet sign and then we do five dash and I'm going to go seven slash 16.
So that's how you would write that dimension and that would be six feet, five and 7/16 of an inch.
Okay.
You don't need your inch sign because it knows what you're working in.
But if we look down here, that's how that's what we've got.
So let's go back to units.
So that's the difference really, between the architectural and the fractional.
Here.
It will keep it in inches.
So it will say your total inches.
However many feet it is, architecture will say your feet.
Decimal as we've seen.
We'll do so ten point.
In fact, let's do more.
Let's do 24.5.
Okay.
So that's 24.5in.
And engineering.
Is going to split it.
So two feet, 0.5in.
So you've got the whole option there.
You've got total inches with no feet.
You've got feet and inches as a fraction.
You got feet and inches as a decimal and you've got total inches as a decimal.
So that should cover you in terms of imperial for whatever you want to do.