THE ACU-CAST PROCESS
Master Model
The Acu-Cast Process begins with a master model. These
models can be created in a variety of ways. We can build
models from furnished prints or by utilizing your solid
modeling capabilities via STL files.
Inspection
Upon completion, the Master Model is inspected and
documented, using prints or STL file dimensions, to ensure
accuracy.
Pattern Tooling
The Master Model is then placed on a parting board to
establish the parting lines of future molds. A temporary
rubber negative is then made of the Master Model. The
permanent rubber positive is then created from those
negatives. This permanent rubber tooling makes it possible
for us to get duplicate prototypes or short-run multiples.
Plaster Mold
A plaster slurry is then poured over the rubber tooling
(positive) to produce a plaster mold (negative). This
plaster mold is then placed in an oven for 12-14 hours and
baked to assure that all moisture is removed.
Metal Part
Both halves of the plaster mold are then assembled and
the cavity poured with a wide range of aluminum or zinc
alloys. As the metal cools and solidifies the plaster is
then broke away from the casting and disposed of.
Trim
At this stage of the process the gates and sprues are
removed. The casting goes through a visual check and
straightening process prior to being inspected, machined and
shipped.
First Article Inspection
The casting is processed through our Quality Assurance
Department where a visual and dimensional inspection is
performed on the casting and any secondary operations.
Secondary Operations
Castings at this point are ready for secondary
operations (per customer specifications):
A. Heat treatment
B. Machining
C. Chemical film, chromate conversion, paint or
special finishes
D. Assembly |
|
TOLERANCE REQUIREMENTS
Whenever a master model is needed to create production
tooling, an accumulative tolerance scheme is required.
Following is a brief description of the tolerance
requirements used by the Acu-Cast Process. These are the
general guidelines established by Acu-Cast Technologies.
Each job can be discussed on an individual basis.* Please
feel free to contact any of the management staff for further
details.
The Creation of a Master Model from Blueprints
Tolerance required for master models built using customer
furnished blueprints are as follows:
| 0.000
to 1.000 |
+-.005 |
| 1.000
to 3.000 |
+-.008 |
| 3.000
to 6.000 |
+-.010 |
| 6.000
to 12.000 |
+
-.013 |
|
Each additional inch requires +-.001 |
|
Angles +-.5 degree |
The Creation of a Master Model from STL files
Master Models built using customer furnished STL files and
built on layer manufacturing machines require additional
tolerance due to warp and surface finish. Due to the short
shelf life of the material used in these models, only one
production tool can be produced.** If long-term production
is required, a permanent tool can be manufactured.
Contact us for further details.
| 0.000
to 1.000 |
+-.008 |
| 1.000
to 3.000 |
+-.010 |
| 3.000
to 6.000 |
+-.012 |
| 6.000
to 12.000 |
+-.015 |
|
Each additional inch requires +-.0015 |
|
Angles +-.5 degree |
Customer furnished master models will be our starting
guideline to determine tolerances for our castings.
Production Tooling and Casting Requirements
| 0.000
to 0.500 |
+-.005 |
| 0.500
to 1.000 |
+-.010 |
| 1.000
to 6.000 |
+-.015 |
| 6.000
to 12.000 |
+-.020 |
|
Each additional inch requires +- .002 |
|
Angles +- .5 degree |
Across parting lines and cores require an
additional +-.010 |
In many cases secondary machining operations can be
performed to maintain closer tolerances if needed. |
