- [Instructor] We're starting a chapter now
in our AutoCAD Essential Training
where we're going to be taking a look
at the units and the options in AutoCAD.
So when you open up the drawing,
you can see that we're in the Model tab,
and there's a floor plan available in the Model tab.
We won't need to go into
any of the Layout tabs at this point,
we're just going to look at the unit settings
in this particular video.
Now, the quickest way to get to your units
in any AutoCAD drawing is just to literally type units,
and you can see it pops up there on my dynamic input
on the suggestion menu,
so I just type units and I press Enter,
that's it, quick and easy.
This will bring up the Drawing Units dialogue box.
Now there's a number of things in here
that we can ignore immediately
because we're not actually working in 3D right now.
So the lighting here at the bottom
you can completely ignore,
that's all to do with lighting and the lighting units
when you are lighting up a rendered scene
in a 3D AutoCAD model.
However, we do need to look at the units
for length and angle at the top of the dialogue box.
So we've got length and angle,
and we've also got an insertion scale,
which I'll talk about in a moment.
So length is the length of a line, for example.
So do you want that in a particular type of unit?
Now in this particular drawing,
it's in metric millimeters.
Now, we will jump around with units and things
in this particular course,
but because I'm English,
I work in metric millimeters most of the time.
So in Great Britain, in the UK, we use metric millimeters
for a lot of our projects,
in the USA, for example, it's feet and inches,
so those units do vary
and that's where the drawing units come in.
So in this drawing, you can see the grid lines
and the dimensions there in the floor plan,
they're all using a decimal metric millimeter setting.
Now AutoCAD doesn't promise you an exact unit setting,
like oh, I'm using metric millimeters,
it doesn't do that, it displays the unit
in a real world environment for you in the Model tab.
So I could potentially have the same drawing
using metric meters, for example,
so that 9601 dimension that you can see top left there,
that would be a very different measurement,
that would be 9.6 meters,
but I can set the settings for this
and how they display in the Drawing Unit's dialogue box.
So what I've got is some different types of unit of measure.
So if I went to Architectural like so,
can you see, it's feet and inches.
If I went to decimal, it could be decimal feet and inches,
it could be decimal millimeters,
it could be decimal meters.
In my case, as you can see,
I've drawn that using those units,
so there are 9,601 units on that top left dimension.
The precision that I'm working to
can vary up to eight decimal places,
and that's the same with whatever unit type I'm using.
So I've got two decimal places there.
If I went to something like Architectural again,
or perhaps Engineering,
can you see, it shows me there the different precisions
I can work to, again,
depending on what type of unit setting I'm using.
I'll go back to Decimal there
and set that back to two decimal places.
AutoCAD actually works to 20 decimal places
in the background using the processor of your computer,
so it's a pretty accurate product.
So that's our length units there,
and as I said, you can use five different types.
Scientific's, quite interesting,
that's one times 10 to the power of 01,
that E represents exponential function.
So we've all heard of things like,
you know, one times 10 the power two is 100, and so on,
that's what that's using there,
but for our purposes, decimal is absolutely fine
for this drawing, with two decimal places.
Now again, angles, we've got some different settings there,
I could use degrees, minutes and seconds,
and there's the presision there.
So we've got degrees, minutes and seconds
where a degree is 60 minutes
and a minute is 60 seconds.
If you've done any orienteering or map reading,
you'll know that degrees, minutes, and seconds
are often used on map reading, for example.
If I go back to something like gradients, for example,
that's all based around pi, 3.14, as is radians,
and Surveyor's Units tend to bring in things
like points of the compass,
so a surveyor would use north, east, south, and west
as points of reference.
So again, you've got different types of precision there.
Again though, for simplicity
for the majority of this course
we will be using good old Decimal Degrees.
Now a little rule of thumb is
you always double the precision of your degrees
as compared to the precision of your length.
Now there's a reason for that,
as an angle gets bigger,
like a slice of pie coming out
from the sort of main apex vertex of the angle,
it's going to get wider isn't it,
and if you haven't got the precision of that angle right,
it can make a massive difference
as that angle goes out over a length.
So it's really important that you make sure
that you've got a suitable precision for your angles
to avoid any sort of like transferred errors there.
So for example, you might round an angle up to 42 degrees
but it might actually be 41.67 degrees
as that angle goes out like that piece of pie shape,
that distance, that measurement of that arc
across that angle gets bigger and bigger
depending on the length of each side of the angle,
so it's really important
that you set those precisions properly
in your drawing units.
We also have here the Clockwise button.
I can switch that on or off.
By default, most AutoCAD drawings measure their angles
counterclockwise, or anti-clockwise,
so that box tends to be unticked.
You may have project settings or company settings
where that box is ticked for various reasons,
but for the purposes of this course
we will be using the counterclockwise rule
for things like angles and arcs, et cetera.
Now, an insertion scale here
tells me which units to scale inserted content to.
So in this particular drawing, I'm using metric millimeters,
so I would go and select millimeters.
Now there's a big list of units here.
AutoCAD is compatible with all of these units
even parsecs down at the bottom of the list.
I'm sure we've all heard Captain Kirk mention parsecs,
I'm sure we've heard parsecs mentioned in Star Wars,
yes, they are a massive unit of measurement
but they're there,
along with things like astronomical and light-years,
going all the way down to things
like millimeters, for example, and microinches.
So you've got all different types of units
that you can scale inserted content to.
In my case, I would want any content
to scale to millimeters
because my drawing is in millimeters,
in this particular case.
You also get a little sample output there as well
showing you what your output will look like.
So there's an angle there with the four decimal places
and some distances with the two decimal places.
And also, we've got direction here,
just click on the Direction button
and you can see there that we can and set our base angle.
Now at the moment, our base angle
is going to the east, to the right,
that is where zero degrees is.
If I'm measuring counterclockwise,
going up to the north that's 90 degrees,
and so on, going around the points of the compass,
and again we will stick with east as zero
for the majority of this course,
unless I tell you otherwise.
So we'll click on OK there
and we'll click on OK there,
and all of our units are now set in our AutoCAD drawing.