|
|
|
|
|
|
|
|
|
|
Part 3 Adding the Ball Bearings
|
|
|
|
|
|
Video Tutorial of this pages contents |
|
|
|
|
|
In
Parts 1 and 2 we created the bearings inner and outer race,
now we need to add
some ball bearings. The 608 bearing has 7 balls so we will create and
position one ball and then use a similar spin process to position the
other six. This time though we will use "Spin Dup" to duplicate the
selected vertices of the first ball around the cursor at the required
step positions.
In front view Num-Pad 1,
go into edit mode Tab,
select wire frame Z,
and de-select all vertices A.
Before
we insert a Sphere to use as the ball bearing we need to
position the cursor
central to the bearing groves of the inner and outer race. To do this
we will hide all the vertices of the bearing race other than the
perpendicular section directly above the cursor. |
 |
|
|
|
|
|
|
Press B
(Box Select) and drag a selection box to select all the vertices to the
right of the vertical centre line. Press B again and select
all the
vertices to the left of the centre line. Repeat this again to select
the remaining vertices below the horizontal centre line. If you select
the wrong vertices simply press Ctrl-Z
to undo the selection.
You should be left with only the vertices directly above the bearing
centre deselected.
Press the H
key to hide the selected vertices. The vertices haven't been
deleted they are hidden so they don't clutter the view and cant be
edited. You can retrieve these vertices at any time by pressing Alt-H. |
 |
|
|
|
|
|
|
You
will now have one row
of vertices directly
above the bearing centre.
 |
Press NumPad
3 to go into side view and select RMB the centre
vertex
of the inner race bearing groove. Now add to the selection Shift-RMB
the vertex directly above this on the outer race. The centre of these
two vertices is the centre point for the ball bearing.
Press Shift-S
to bring up the snap menu and select
Cursor->Selection. The cursor will be positioned at the
insertion point for the first ball. |
|
 |
|
|
|
|
|
|
Unhide
the vertices we
hid to make positioning the cursor easy by pressing Alt-H. Change to
front view NumPad 1
and Tab
into Object Mode. You will see the cursor positioned between the
bearing races directly above the Object Centre.
 |
To
form the ball we will use one of Blenders preset objects, the UV
Sphere.
The sphere is constructed from a series of latitudinal and longitudinal
edges with poles at the top and bottom.
We will be using the geometry from the sphere to construct the bearing
cage and it is important that it is oriented correctly.
|
When we insert
the sphere we need one of the poles to be pointing towards the bearing
centre. To
achieve this it is necessary to insert the sphere whilst in the top
view, so press Num-Pad 7
for the top view and then press the Space Bar
to open the Toolbox. select: Add > Mesh >
UVsphere. |
 |
|
|
|
|
|
|
|
Accept
the default 32 segments and 32 rings, a UV sphere will be
inserted centred on the cursor with a diameter of 2mm. The
mode
will have switched to Edit Mode and all the vertices will be selected.
If you click into front view Num-Pad
1. You will see the bearing is hanging in space and too
small for the race. To correct this we need to scale the bearing.
|
 |
|
|
|
|
|
|
To
obtain the correct scale factor, divide the required size of the ball
by the inserted size of the UV sphere. As the balls are 3.95mm diameter
and the UV sphere is 2mm then: 3.95 / 2 = 1.975.
Press S for
scale 1.975
for the amount and Enter to
accept. The ball now correctly fits
the race.
| Blender
2.44 Update |
 |
When you add a UV sphere
there is a new floating panel that allows you to specify the radius,
along
with the segments and rings of the sphere. So you no longer need to
calculate the scale factor when imputing some of the mesh primitives. |
You can now
simply hold
down Shift
and Click LMB
over the radius figure and input the new radius of 1.975 and click OK.
The UVsphere will now be inserted at the correct size.
Its
still good to understand how to calculate a scale factor, as it will be
needed in many other modelling situations. |
|
 |
|
|
|
|
|
|
The
Object Centre for the
ball is currently central to the UV Sphere
and it would be much more useful if it was positioned central to the
Bearing. To achieve this Tab
into Object mode and select RMB
the
bearing race. Press Shift-S
to bring up the snap menu and select
cursor->Selection. The cursor will be repositioned to the centre
of
the bearing. Now reselect RMB
the Ball
 |
In
the Mesh Panel there are three options for
moving the cursor.
Centre: moves the object so it is centered over the Object Centre.
Centre New: Moves the Object Centre to the centre of the object |
Centre
Cursor: moves the Object Centre to the cursor position, which is the
option we require. |
 |
|
|
|
|
|
|
With
one ball in place we now need to create the other six. As the cursor
is on the bearing center we can duplicate the first bearing 7
times around the race.
To
achieve this Tab
into Edit Mode.
In
the Mesh Tools panel set the Deg: and Steps: as shown.
Press
Spin
Dup to duplicate the vertices seven times around the cursor. As with
the spin command we have just placed a copy of the original ball over
the top of the first one. To correct this select all vertices A. You will need to
press it twice, once to de-select the last ball and then to select all.
Press W
(Specials Menu) and then select remove doubles.
|
 |
|
|
|
|
|
|
To
change the appearance
from the faceted surface of the UVsphere to a smooth
surface,
with all vertices selected click "Set Smooth" in the Links and
Materials panel.
The balls are now created
and positioned around the bearing. Press Tab to go into
Object Mode, Z
for solid view and rotate the view with the MMB to see the
bearing as a 3D object.
In
the Links and Materials panel rename OB:Sphere to OB:608-Balls
If
you haven't already done so press Ctrl-W
and save your work.
|
 |
|
|
|
|
|
|
Part
4 modeling
the cage becomes a little more tricky but as you get used to panning,
rotating and zooming the view, selection of vertices and constructing
models becomes a little easier to achieve. |
|
|
|
|
|
The following is a video
tutorial of the above information |
|
| Top |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
