Sliding core tutorial (using side core tool)

The following tutorial demonstrates

the process of modelling a sliding
core.

This will use the side core tool

Modelling the component

First of all model the component
shown opposite.

Working on top plane drawing a

rectangle 120 x 80mm then extrude
upwards by 40mm applying a draft
of 10 degrees.
On completion, apply fillets of 10mm
and shell from below with a wall
thickness of 5mm.

Using the clipping plane the

component should look as shown.

Modelling the cut-out

Next we will add a cutout to the right
hand end as shown. This will be
achieved by creating the cut of
dimensions shown below, adding
fillets or radius 2mm and the
applying draft of 5 degrees and
drafting outwards from the inner
edge.

A sliding core will ultimately be

required to form this detail.

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Modelling the mould
Next carry out the standard steps in
preparation for creating the mould
base.

Finally using appropriate dimensions

create the core and cavity block
using the ‘Tooling split’ command.

Next hide the surfaces and activate

the clipping plane to see the internal
detail.

For improved clarity, modify the

colours of the individual solid bodies.

As Solid Works uses green and red

for the core and cavity surfaces
respectively, I suggest that you might
use the same colours for the core
and cavity solid bodies.

[Colours may be set by expanding

the feature manager, selecting the
appearance icon adjacent to the
solid body in question and then
selecting the colour required.

When selecting colour I recommend

colours from the second row as
colour below this come out very dark
when printed.]

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Modelling the slide
On examining the mould in the region of the
cutout it wll be clear that in order to release the
component the piece of metal which forms the
shoutout must be retracted. This is referred to
as and undercut. As the component remains on
the core when the mould opens; if the detail
which forms the shutout were to remain part of
(and move with) the cavity side or fixed half then
this secment would need to be fully retracted
before the mould can even start to open.

The alternative is for this segment become part of the moving half or core
side. By doing this it is possible the allow the segment to be retracted while
the mould is opening.

This is usually achieved by using guide pins or,

where movement is small, by spring loading the
slide against an angled face.
It is therefore necessary to cut this segment
from the cavity block to produce a slide. It will
then be dovetailed into the core side or moving
half.

Working on the end of the block create the sketch shown above.
On completing the sketch, select the side core
tool and choose ‘up to next’ option.

This will separate the segment shown from the

rest of the cavity creating a new stand alone
solid body.

You are now ready to construct the assembly. To do so export each of the
solid bodies (core, cavity, slide and component) as stand alone parts using
‘Insert into new part’ and then insert them into an new assembly.

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Creating the mould assembly
First of all create a new assembly called
Slide-mould.sldasm

Next insert each part into the mould

dropping each part at the origin by
choosing accept.
For clarity change to cavity half to
transparent. The assembled mould
should now look as shown opposite.

At the moment all components are fully

fixed, denoted by the letter (f).
As we ultimately want to observe the
movement of the mould and slide as the
mould opens we want to free up some
degrees of freedom.

To do so right click on the cavity block

and choose Float.
Next apply assembly relationships to the
two pair of corresponding side faces. A to
A and B to B. Next drag the cavity block
upwards as if to open the mould.

Next ‘Float’ the slide.

To restrict lateral movement, mate the

side of the slide with the side of the slot in
the cavity block (C to C).
Finally mate the underside of the slide
with the parting surface of the core block
(D to D)

Now the cavity block is free to move

vertically while the slide is free to move in
and out as illustrated.

Next we will need to devise a system to

move the slide as the mould opens.

In this case we will use an angled face on

the slide. This will be operated by angled
face in the cavity block.

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Guiding slide movement.
In order to move the slide there are two
possibilities. i.e. guide pins or angle face.
In this case we will used the angled face.

In order to clear the component the slide

needs to retract by 7.2mm over a mould
opening distance of 18mm (this requires an
angle of O = Tan-1(7.2/18) = 21.8 degrees). To
allow some clearance we will use an angle of
25 degrees.

To achieve slide movement the slide must be

enclosed by the cavity block in order to create
the angle face to operate the slide.

To achieved we will cut 10mm of the end of

the slide and add a 10mm wedge to the outer
end of the slide channel.

Modify both slide and cavity block as outlined.

So far the detail looks as shown.

Next we need to draft the back end of the slide

and the corresponding face in the cavity block.
Edit each component in turn and specify a
draft angle of 25 degrees.

The arrangement should now look as shown

below.

Finally mate the angled

faces of the slide and
cavity. The will result in
the slide moving
correctly as the mould
opens.

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Operating mould movement.
Mate relationships are usually infinite. i.e. an axial relationship applied to the
rod and cylinder of a hydraulic ram does not limit movement. i.e. rod is free
slide indefinitely in either direction.
To limit movement a mate relationship between the piston and end of the
cylinder is obviously possible. Different levels of extension can be represented
by different distance values.
However, it may be required to allow the rod the slide freely but within
realistic limits. While collision detection is possible this can be demanding in
terms of computer processing time.

Instead a limit mate may be used.

To apply a limit mate select the parting faces
of the mould, choose the mate command then
under Advanced mates select the distance
mate option. Specify :-
0mm as the minimum value
50mm as the maximum value
30mm as the current value.

This will move the block to 30mm apart but will

allow you subsequently to drage the block
between 0 and 50mm.

Move the cavity block and watch the slide move accordingly.
Note the CAD mate between the angled faces is maintained even when not in
contact. This is because mate relationships are infinite.

In reality the movement will only operate while slides are in contact, therefore
slide movement will need to be limited so that angle faces will come in contact
when mould closes.

Finally we need to add the engineering detail necessary for the slide to
function i.e. a T-slot. Working on the core, create the sketch shown and cut to
an appropriate depth. Add the appropriate detail to the slide to enable it to
slide in the slot.

This completes the mould slide tutorial.

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