THE ACU-CAST PROCESS
Master Model
The Acu-Cast process begins with creating 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 blue print or STL file dimensions, to
insure accuracy.
Silicone Casting Tooling
The master model is then placed on a parting board to
establish direction of pull. A silicone rubber negative is
then made of the master model. This silicone rubber tooling
makes it possible for us to duplicate prototypes or
short-run multiples. After removing the master model from
the silicone tool the tool is assembled.
Plastic Prototypes
Vacuum Casting Resin is measured precisely into Cup A
and Cup B. Place both cups into the top chamber and the
silicone tool in the lower chamber. Automatically de-gas,
mix and pour the resins with the pre-programmed casting
cycle. As the resin flows into gates or runnels the tool is
pressurized to ensure void free parts. Remove the cured part
from the mold after oven curing.
Trim
Finish the replica of the master by trimming off gates
and runners.
First Article Inspection
Check for dimensional accuracy to the initial master
model.
Prototype Run
Continue producing consistent quality parts with
material and color versatility in the vacuum casting system. |
|
TOLERANCE REQUIREMENTS
Whenever a master model is needed to create plastic
prototypes, 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 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.
| .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.
Silicone Tooling & Casting Requirements
| .000
to .500 |
+-.005 |
| .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 core require additional
.010 |
In many cases secondary machining operations can be
performed to maintain closer tolerances if needed. |
