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DSPC Capabilities

It's not just what we make,
    it's what we make possible!

Direct Shell Production Casting (DSPC) is a proprietary fabrication process for metal parts which combines the advantages of both casting and machining and eliminates the disadvantages of both processes.

The patternless DSPC process produces functional cast metal parts directly from your CAD file. In addition to shortening lead time and saving cost, eliminating casting tools add tremendous design flexibility of complex cast parts which is essential during the development phase. Soligen has combined DSPC, conventional casting techniques and a modern CNC machine shop to yield a "one stop-shop" for cast and machined metal parts and supply them as ready for assembly.

DSPC enables the production of metal parts directly from CAD files.

Alloys
Surface Finish
Accuracy and Feature Sizes
Drafting, Blending and Fillets
Vaccum Casting
Casting Grades
Part Size

(also see design recommendations for metal casting)

ALLOYS:
DSPC enables casting parts from any castable alloy. A partial list of alloys:

  • Aluminums: 206, 319, 328, 356, 357, 390
  • Magnesium: AZ91
  • Copper, Brass, Bronze
  • Irons: ductile, austempered gray, malleable, Si moli
  • Stainless Steels: 3xx, 4xx, 17-4ph, 15-5ph
  • Super Alloys

SURFACE FINISH:
DSPC and production castings are normally shot blasted. Our default DSPC parts surface finish is "as printed". As these DSPC molds are cast, some of the surfaces of DSPC parts contain "stair steps" of approximately 0.005" to 0.007". Shot blasting and gating removal removes most of the stair steps from external surfaces and near areas of gating. When required Soligen can provide hand finishing of DSPC castings to a finish of approximately 125 to 150 micro-inches rms. Proprietary ceramic coatings that are compatible with metal casting can improve surface finish of internal cavities and other areas when access to hand finishing is restricted. Casting appearance can be improved with your express instruction and at additional cost (please consult with Soligen technical team on available finishing processes).

ACCURACY AND FEATURE SIZES:
Soligen uses either gravity or low pressure casting processes to produce DSPC parts, therefore casting rules of thumb should be observed. The DSPC process is capable of producing a net shape casting. When you send a file, unless you otherwise instruct us in writing, we will produce a cast metal part that will match your STL file (except for un-castable features)*. While the DSPC process tends to produce molds that are more accurate than standard sand casting, in order to make your parts more produceable, you should generally assume that the accuracy of the part will conform to standard casting tolerances. For tolerances on non-heat treated DSPC cast parts, refer to the following table: Dimension Tolerance (inches) Equal or smaller than 1 inch +/- 0.021" Between 1" and 6" 0.021 + 0.002" per inch Greater than 6" 0.031 + 0.003" per inch over six inches Angles +/- 30' * If we detect non castable features, Soligen will contact you to receive your authorization prior to any modification of the CAD file.

DRAFTING, BLENDING AND FILLETS:
DSPC castings do not require drafting and fillets, because there is no tooling per se which must draw. The DSPC part will therefore be identical to your STL file in this respect, i.e., if drafts and fillets will be in the part only if they are in the part file. Sand castings are often modified from the original geometry so that the tooling can be withdrawn from the sand without damaging the imprint. So, if you plan to order multiple pieces i.e., sand casting or low pressure permanent mold casting (short production runs) and are not aware of the constraints under which a pattern maker will operate, please make your requirements clear and indicate so at the time that the request for quotation (RFQ) is placed. To avoid casting defects, which result from sharp corners, we recommend that you include fillets and avoid sharp corners in intersection of walls. Our technical team will be happy to assist you. Another important consideration in cast part design is to make an effort to keep the walls thickness of the part as uniform as practically possible. That is because a transition from thick to thin wall section is sensitive to shrinkage due to uneven solidification. Sharp corners and unblended transitions are the most sensitive. You should therefore attempt to blend and fillet intersecting sections. To increase the likelihood of getting a sound casting the design should call for smooth blending and as large a fillet diameter as possible.

VACUUM CASTING:
DSPC shells are suitable for vacuum casting which enables high definition, wall thickness that is thinner and a higher aspect ratio than those achieved in gravity casting. Since DSPC yields a solid ceramic mold (no organic binders) it does not outgas. It also allows pouring at elevated shell temperatures (similar to investment casting).

CASTING GRADES:
Designing the gating in CAD enables us to feed the cast part in more directions and entries than conventional casting. Embedding metal chills is an additional feature that DSPC incorporates freely. These enable us to better control the direction and rate of solidification of the part as well as eliminating shrinkage and other casting defects. Thus DSPC is a perfect process to develop high grades of casting.

PART SIZE:
This is not a limitation. The printing envelope of our DSPC machines is 14"x18"x14" inches. However since ceramic molds can be assembled from multiple ceramic pieces, the final casting mold can be much larger. We have successfully made castings as large as instrument panels for SUV vehicles and as heavy as a Tomahawk missile body. (weighing hundreds of pounds)