- [Instructor] The main parts of the frame are now complete.
But with items like bike frames,
the devil is in the detail really.
By this, I mean that we can now potentially add
all sorts of different extra items
that will actually allow the frame to be more useful.
These could range from small extra mounting points
for bottle cages to areas
where you can mount your brakes and gears.
Depending on your exact setup,
these will vary hugely.
So it's really up to you what kind of items
of hardware you add.
In this first video,
I'm going to model up
and add two mounting points for rear rim brakes.
These are just an example really
because maybe you want to use disc brakes or another kind.
In which case, you probably have mounting points
down here on the chainstay or seats stay
or maybe built directly into the rear dropouts.
But for this style,
we'll just model up a simple boss that's got a threaded hole
that the actual brakes screw into.
If you're starting fresh from this point
and using the exercise files,
then unzip the chapter four files to a new folder
and then open the assembly file for chapter four.
Then start a new part
and start a sketch on the top plane.
Select the circle tool
and draw a circle at the origin.
Make it 15 millimeters diameter.
And then do a blind extrude 20 millimeters.
We'll now make a tapped hole down the middle of this,
so get the Hole Wizard.
Choose straight tap which is this one.
Make sure you're in ANSI metric, size M10 by one,
and then End Conditioned, Through All.
Then for the position,
let's just select this top face.
We'll position the hole at the origin and press okay.
And that's the entire part.
So it's just a small tube with a tapped hole through it.
And we can save this part as something like Brake Boss.
Now go back to the open assembly
and let's insert that part.
You can do this by going to Assembly, Insert Components,
and the brake boss should be open there.
If you don't see it open there,
you can just click Browse
and find the file on your computer.
Let's insert one of them in roughly this position.
Let's drag it around
by dragging with the right mouse button
so it's roughly the correct orientation.
And then we can fix it exactly in place by using mates.
Expand the Brake Boss part
which should be the latest part in a part string
and then select the Top Plane.
And then hold down control
and also select the Seat Stay Plane.
And then release control and add a coincident mate.
So if you look from a side view,
the brake boss should be sticking out
of the back of the bike like this.
If you find it sticking out of the front,
then what you can do is expand that Mates folder,
find the latest mate, right click on it,
and press Flip Mate Alignment.
So if yours is sticking out of the front like this,
just expand that folder, find that latest mate,
right click on that Coincidence Mate,
and press Flat Mate Alignment.
Now we can set the position along this chainstay.
So this will really depend
exactly on your brakes and your wheels,
but I'm going to set mine at 240 from the rear axle.
To do this, I'm going to expand that Break Boss part.
I'm going to choose the Front Plane.
And then hold down control, move around to 3D,
and then also select that rear axle line.
And then release control,
and I'm going to add a distance mate of 240 millimeters.
And press okay.
So now we just need to fix
the exact left right distance of the brake boss.
We can do this by first selecting the Seat Stay Plane
and then go into a normal tool view.
Remember you can open this view menu
by pressing the space bar.
So you may need to press it twice
so we can see from the correct direction,
but we need to set this left-right distance.
Because this seat stays angled,
this will depend exactly on the distance
that you set from the axle.
But for me, I'm going to drag it around
to roughly the correct place.
It's in the middle of the tubes, something like that.
And I'm going to expand the Brake Boss part,
select the Right Plane, hold down control,
and also select the Right Plane in the assembly,
and then release control,
and then add a distance mate.
And for me, 55 millimeters works pretty well.
So it's now a fixed in position there.
And if we look in 3D,
that looks pretty good.
Then next, we want to trim away the back of the brake boss
so it sits nicely against that tube.
To do this, let's just right click on the part
and press Edit Part.
And then let's use a cavity feature.
So go to Insert, Features, Cavity.
In the design components,
let's just select that seat stay part, press okay.
And then for the bodies to keep,
click on Selected Bodies.
We just want to keep that outside section.
So for me, it's this one.
Press okay, and now we've cut away that back there.
So you can exit editing the part,
and that's looking pretty good.
Now all that remains is to mirror this part
over to the other side.
We actually already have a mirror feature in the assembly
that we used to mirror over these parts
of the rear triangle.
So we can use that feature to mirror this part as well.
Find that mirror feature.
It should be the latest feature in your parts tree.
Click on it and press Edit Feature.
And then just click in this Components to Mirror box.
Choose that latest part, the break boss,
and then click Next.
And then select the Brake Boss,
and let's make an opposite hand part.
So click that button, press okay.
If you get any warnings about the material,
you can just press okay.
And if you get any warnings about the units,
you can also just press Yes.
So now we've got that second break boss on the other side
and everything looks good in 3D.
So we've now got two mounting points
that we can attach the brakes to,
and at this point you can save your assembly.