Posted to News on 28th Dec 2005, 00:00
The art of sand casting
Sand casting is an art as old as technology itself, but the accuracy of modern day sand casting ranks it alongside the best metal forming techniques available. Both cost and styling benefits suggest designers should give it serious consideration for anything less than high volume production, although runs of several thousand are quite possible.
Aluminium casting techniques at Norse Precision Castings can achieve tolerances of 0.4mm and wall thickness of 3mm, and sizes approaching one metre cubed. The almost infinite versatility of shape allows the designer unbound freedom of style and functional shape. Whilst pattern making is critical, sand technology also plays a key role. In larger structures, up to eight or ten complex cores are carefully pieced together for the final mould. A significant advantage of this is that product variations can be economically accommodated as frequently only one or two pieces need to be changed.
The adhesive provides some degree of strength to the sand but a high degree of cleanliness and care on the shop floor is needed to produce accurate repeatability and a consistently high quality of finish. Experience in mould design, particularly the feeders and the excellent fluidity of aluminium, enables cavities and strengthening ribs, even logos, to be incorporated. Good machinability post casting then allows the finished part even tighter tolerances, with tapped holes, machined flats and slots.
