CNC , INVESTMENT CASTING, et. al.
No such thing as a stupid question ?
I ASSuME by the context of where I read this that it is a construction technique. Can someone give me a short definition of any?
I ASSuME by the context of where I read this that it is a construction technique. Can someone give me a short definition of any?
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Try this link... it explains it quite well. Ruger uses this process for their handguns (not sure about their rifles).
http://www.ctiparts.com/investment_casting.htm
Bert H.
Real Men use a SINGLE-SHOT!0 -
its done for precision, and is a good process, in a normal casting that is done and precision mesurments are needed on the casting it would need to be machined to size after casting, this process takes away the need for machining, the only draw back to it is that sometimes the quality of metal used may cause weakness in the part our casting, also if its not casted properly air pockets will form sometimes withing the material that cannot be seen and also makes a weak casted part, to check for this there is a process that they x-ray the part but most companys don`t x-ray do to the cost of the process and if its required the price of the casted part is high. hope i helped.
mag44pistol0 -
"CNC" and "INVESTMENT CASTING" are two different manufacturing processes.
"CNC" is Computerized Numerical Control, this is high precision machining controled by a computer program.
The two previous posters, gave you a good rundown on Investment Casting.
When the above two processes are used in conjunction, the machines run by the CNC programs, machine the final, very tight tolerences and required finish on the Investment Cast parts.
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Bert Hs link gives the closest description of the actual process and the metals like 17-4PH, a miraging, stainless steel used by some gunmakers. Parts come out of the process so close to final size that only minor finish machining is required. Aside from the possibility of inclusions and voids in any casting, the direction of crystal formation on cooling is from outside inward which is less than ideal for stressed parts, giving them inferior properties to a similar part formed by forging or rolling where grain flow follows the contour of the part. There is no cure except to use more material or higher strength steels like 17-4PH. This precipitation hardening steel is super strong and is used by Cassull for his hand cannons.
Ruger is a leader in having worked the kinks out of the investment casting process for making reliable gun parts.
CNC machining centers are completely automated machine tools having cutters, driven by computer programs, that can completely manufacture a gun frame from a block of steel or aluminum.0 -
Hey v35, we are finally beginning to agree on stuff! Just thought I'd throw in, maraging 17-4PH stainless steel is ferromagnetic after heat treat (attracted to a magnet). It is tough stuff, even in the cast form. Years ago, I was working at a popular builder of business jet (the kind you might be vain about), doing an in-service inspection on a 17-4PH engine mount that was originally cast material. A crack was found on inside surface of the casting using magnetic particle inspection, crack was about an inch long. This was after several hunderd hours of service, I forget, maybe a half- life inspection. We pulled the original radiographs (x-rays), the crack was there when the mount was new. The original film interpreter had written the indication off as a screen artifact (non-relevant, due to lead intensifying screens). The interesting thing is, the mount was re-xrayed at the same settings, same geometry, it was determined the crack had not grown a bit since it was new. The material is tough stuff, even with those kinds of flaws. I wouldn't worry much about cast 17-4PH gunparts. Even though I do like to rub people about their cast M1A receivers.
To err is human, to moo is bovine.0
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