- [Instructor] So here, I wanna talk about datums,
datum planes, axises, datum CSYS.
Under our home tab, we have our datums.
And datums are really a very powerful element.
They're extremely stable and very useful.
There's a lot that you can do with datums.
I highly recommend you get very familiar with them.
You can offset datums to create an actual datum reference.
So if you're building something,
let's say at the aft end of a vehicle,
especially if it's a large product of some sort,
like a car or an aircraft, whatever it may be,
having a datum setup as a reference turns out
to be a more of a necessity than a want.
So if I click on the little black arrow here
you'll notice I have a datum plane.
Here's my axis and datum CSYS.
We'll be talking about these here
and a little bit about points as well.
So I'll start out with datum plane.
Click on that and you'll notice
that I have several types of datums that I can create.
By default I typically just start out with inferred
and if I can't get what I want with the inferred
I just basically switch to the type
that I specifically want.
I'm not gonna talk about all of these.
I'm gonna talk about the primary ones that we're gonna use.
So I'll switch to inferred.
You'll notice that once I select on inferred
I have a lot of my selection intent options pop up
and are available to me.
So again, these are very important
to what you're doing here.
Now objects to define a plane.
This is pretty straightforward.
I select my plane,
in this case the zy off of my initial datum CSYS
and you'll see here I can do an offset.
Simple basic offset.
I can move this around.
I also have the ability to scale my planes.
So if I want to I can grab one of the little handles here
and make it bigger, smaller, whatever you need to do.
The planes will try to scale them size
to the actual part that you're working on.
So if you're working on a large part
and you pick a face off of that it'll scale to that face.
If you pick a small face it'll scale to that small face.
So sometimes you have to actually make the planes
bigger or smaller to fit your screen appropriately.
You also have options here to increase the number of planes.
Let's say I hit five.
What's going to happen is I'll get
five equally spaced planes,
and if I increase that offset value
you'll notice the planes also increase
because they are all equally spaced to that offset value
that I indicated.
I can reverse the direction
so if I need to go in the opposite direction,
and then I can also reverse the orientation of a plane
by using this reverse direction,
and what this is for is basically
if you go all the way back and use a plane as a reference
there's a normal so maybe I placed a sketch on that plane
or I offset something off of that plane.
This is the default direction of,
let's say the Z direction off of the sketch
or the offset direction off of that plane.
So if I switch it like that
then that becomes the default direction
for whatever it is I place or attach to that plane.
I'll just swing this back down to one and reverse this
and reverse it again.
Select OK.
So you'll see datum plane here in the tree.
I'm gonna go back into datum plane.
This time I'm gonna pick this plane right over here
and I'm gonna pick the plane that I just recently created.
Now when I do that what's going to happen is,
in this case it's gonna give me a bisector.
That bisector is right at the middle of those two planes.
Select OK and there's my datum.
So now I'm just gonna hide these.
I have a solid body set up right here
so I'm gonna show that.
Select in my datum plane and once again
I'm gonna pick my inputs.
This is one of those where you have to be careful
if you're picking a cylindrical face
you wanna make sure either you pick the face
or you pick the center line of said face.
In this case I wanna pick the actual face.
And here just gives me a datum plane
as a tangent to that face.
Not much I can do with it.
I can do an offset off of that if I want to.
And then I can, again,
cycle the normal direction or plane orientation.
But if I pick a second cylindrical face
like this right here,
you'll notice it gives me a tangent plane.
Now I have alternate solution,
and that's what this alternate solution is for
is I can cycle through the various solutions
that are there based off of two cylindrical faces.
And again I can reverse it.
If I want to, again, do an offset
I can do an offset off of the plane that's created,
and in fashion here I can reverse as well.
And again this is the plane orientation.
So if I select okay, again, it makes my datum plane.
I also can do another datum with bisectors
between two angled faces as you see here.
You'll notice it gives me the bisector,
and let me turn off offset so we can see it
right at the place of creation.
And then you'll also notice an alternate solution.
That alternate solution does a perpendicular plane
to the bisector at the vertex
or where the two faces would intersect out in space.
You'll notice I don't actually
have to have that intersection.
The system knows where that intersection occurs.
And there's my plane.
I'll go back into datum plane.
I do want to talk about an option down below,
it's called associative.
You'll notice that if I turn this off,
when I create a plane it's gonna create a fixed plane.
All that really means, let me go ahead and do an offset,
select OK, is that this plane now has no reference
to history back to the original element that created it.
So because of that it's not gonna move.
So if this gets bigger, smaller, or changes,
this is gonna stay fixed in place.
And this is kinda handy because there are times
when you're designing something
that something can't move, right?
Maybe you have an external reference
that needs to always be exactly the same.
And this is how you go about creating that.
If I need to make a change to it
I can always double click on that plane.
You'll notice it creates a fixed plane here.
Change the type of plane that I want it to be.
Do my offset.
Anything that's created off of it
will use it again as a reference, right?
It's gonna remember that
all of its children features are built off of it.
So they will be built based off of that plane again.
Now if I turn on associative you'll notice
that I can create it and make it a reassociative plane.
So it's not really dead, per se.
You can build it without the parental history
or you can build it with,
and if you need to make a change without history
it's easy to go back in there and make the change.
One more type of plane that I wanna talk about,
let me just go ahead and hide these,
I'm gonna show this spline.
And I'll go back into datum plane.
I'm gonna pick this curve.
You'll notice that when I pick the curve
it dumps a plane, it is radial to the curve,
or normal to the curve depending on the terminology
you wanna use,
so as I drag this along you'll see it always stays normal
or radial to the curve at that point.
I can control that with a percentage of arc length
or an arc length.
So if I need something to be
a specific distance from that end,
maybe I need it to be 120 millimeters off of that end,
it's 120 millimeters,
or I can change this and say a percentage.
Maybe I want it at the exact center of that
I can just say 50% and now we know it's at the exact center.
Some other options that we have here,
alternate solution at that point,
it's tangent to the curve in one direction,
tangent to the curve in the opposite direction.
So you have, again,
those options there at that point location
having those planes set up and created.
Select OK.
As far as the datum axis goes, pretty straightforward.
Let me show you with a datum axis, I can pick a curve,
and on that curve what it's doing is
at that specific location that I selected
it's creating a datum that's tangent to that curve.
Let me go to settings.
Now you'll notice, again,
I have associated similar to the other.
I also have a reverse direction for that axis.
If I want to I can come over here,
and let's do this here.
I'm gonna hold the shift key down,
I'm gonna deselect it.
This time I'm gonna turn on my point on curve.
I'm gonna pick a specific point location on that curve,
and another specific point location on that curve,
and you'll notice the datum axis
runs through those two points,
so gives you those ability to pick a point,
two points form an axis.
If I want to let me go ahead
and bring back the solid bodies,
let me show those.
If you do want the axis,
let's say around that cylindrical face,
you can go back into datum axis and pick that.
And again, you have the ability
to reverse the direction of the axis.
And that's important,
especially if you're doing revolved parts
because the axis does determine the way things rotate.
Remember, right hand rule.
So if the axis is pointing in the opposite direction
it's going to create a revolve in the opposite direction.
So your zero to 180 basically changes.
So you wanna make sure you just set it up and create it
based off of the need for your rotation to spin correctly.
Last one is datum CSYS,
and datum CSYS is basically a combination
of your datum planes and datum axises,
except for this will create there planes and three axises.
So if I come in here and I want a specific type of CSYS
or a location I can use a dynamic,
and I can drag this, rotate it.
Maybe I want this at a specific point.
I can pick a point.
So if I come in say this endpoint,
there's my CSYS at that endpoint.
Once I select OK you'll see it creates that
datum coordinate system.
So pretty straightforward.
Again, if you want to you can come over here
and use various references as well.
Maybe I want it to be at a specific origin
and point in a specific direction,
so I can use additional references here
to orient and create a datum CSYS right where I want.
Again, get familiar with your datums.
They're very powerful, extremely useful tools.