The v-process casting method was first developed in Japan as an innovative method for manufacturing precision automotive components. The process is not widely known by engineers in the United States because it is not highly publicized and there are very few producers in North America.
But the process is really terrific for a number of reasons:
1) the tooling costs are relatively inexpensive.
2) tooling changes can be made easily and cost effectively.
3) precision castings are made with a smooth surface finish.
4) process can be utilized for prototyping as well as supporting production quantities.
5) piece price is competitive with die casting through 15,000 pieces.
Let's take a look at each one of the five reasons listed above. First, tooling is precision machined out of a polymer that is tough and durable. And very easy to machine. Solid models are downloaded to CNC software which creates the tool paths of machine the patterns. Cutting time is fast and tools can be made over a couple of days.
The tools are a replica of the part(model) to be cast. A cope and drag(top and bottom) is made. The tools are then mounted can then be mounted into the V-Process machine. Tooling price ranges from $5,000 to $25,000 (even for the largest parts).
Second, tooling revisions. Minor tooling revisions can be made in less than an hour. Major revisions will take longer but still very quickly. If material needs to be added to a certain section of the tool, blocks can be inserted and cnc machined.
Third, smooth precision castings. Because the mold is made up of fine sand held together by vacum and a thin(.005 thick) surlyn sheet, the castings have a surface finish 125 rms or better. The castings are produced with a minimum wall thicknes of .125.
Fourth, casting setup takes minimal time. Tools can be shuttled in and out of the equipment in about ten minutes. Down time is minimal. Plus the tool can be cycled over and over to produce the required number of parts. Normal production quantities are 500-2000 pieces at a time.
Fifth, the process is competitive with die casting. Now with large automated turnstyle type equipment, cycle times for this process are faster than ever. Large components (24" x 18") can be cast just as fast as smaller components. So if you take into consideration tooling costs for large die cast components ( $ 150,000 and up), you can produce a lot of castings in the V-Process and be competitive with die casting.
If you would like more information about v-process casting, subscribe to www.manufacturingtips.com and request information on aluminum casting
Carl Kruse is a writer, speaker and sales executive in the manufacturing business. He specializes in mechanical component development which includes casting, plastic molding, machining, stamping and prototyping. He can be reached by e-mail at carl@krusetechnologies.com or subscribe to his blog http://www.manufacturingtips.com |
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