- There are some core term definitions
that are important to understanding
the rest of the subject matter at hand.
The first of which is the definition of
molds, mold making, casts, casting, and cycle.
Understanding these specifics now
will help inform your absorption of prototyping methods,
which in turn inform manufacturing technique.
Let's get started.
A mold is a three-dimensional negative of your part,
sometimes called a die or cavity.
The goal of a successful mold
is to capture all geometric features of your original part.
A mold can be made from many different types of materials,
depending on the desired end-needs of your components.
Mold making is the creation of a mold or negative
from your original or master part,
capturing dimensional and textural detail
for the use of creating reproductions
that are identical in form to your original.
Mold making takes the majority of your work time
for procedural planning after the design of the part.
It includes many factors
that will affect your production process
and is the most meticulous procedure
we'll cover in this course.
A cast is a three-dimensional copy of your part,
a reproduction.
A cast can be made from any number of materials,
chosen specifically for the end-use,
reflecting the project requirements.
The goal of a successful casting
is to reproduce all geometric features
of the original master part
with the added flexibility of different material choices.
Casting is a reproduction of your original master part
and refers to the process
of filling your mold cavity or cavities
with material that hardens
and is then removed from the mold
once cured into a stable state of solidity.
In many cases, casting can be repeated
multiple times with the same mold.
A rule of thumb, for ease of prototyping molds,
is that if your final parts are hard,
the mold should have some give.
If your end parts are soft, the mold can be hard.
Casting involves logistical planning
for timing the rhythm of multiple castings.
In prototyping, this process involves
preparing the material,
getting the material in the mold,
the curing processing time,
the cooling period,
removal of the part,
and restarting the process.
In mass manufacturing, this is generally called a cycle.
This cycle is the end-to-end procedure
for preparing the material,
getting the material in mold,
the forming cycle, and the ejection of the part.
Factory cycles are much faster than prototyping,
but involve a much higher initial cost,
which is why full-scale manufacturing
is generally reserved for designs
that have had most of the bugs worked out
prior to the creation of the die for high-volume use.
Let's look at those steps now.
The first phase is the material preparation phase.
The material in storage needs to be converted
into usable stock, sometimes by melting it.
The second phase is the material placement phase.
Once the material is prepared, it has to get into the mold
by pouring, placing, or injecting.
Once the material is in the mold,
the material goes through the hardening phase.
The material changes state and solidifies.
After the hardening phase,
the material still has to cool down
so it maintains it's new shape.
Now that we have reviewed what these core process terms are,
we can start diving into the methodology
of designing for mold making.