hollywoodfoundry Posted November 22, 2011 Share Posted November 22, 2011 I use a New Zealand company for my pewter casting, Zodiac Industries, as do many kit makers in Australia and New Zealand. They do an excellent job, but are not the easiest to make contact with, they do not have a web site. The process used is called spin casting (they also do pressure casting). The spin casting is performed using a rubber 'puck' about 8 inches in diameter. There are two halves to the puck and it is made by embedding the patterns in rubber which is then vulcanised to form around the patterns. The pattersn must therefore be made of a material that can withstand the very hot vulcanising process. This is why I investment cast my 3D builds in Manganese Bronze. This is a proof of a puck sent to a client as a fax: You can probaly make out that the model in this case is a steam locomotive, the variuos items are identifiable as the boiler, smokebox from, domes, backhead etc. In this case, two pucks were required as there were a few more parts than would fit in a single mould, and some needed duplication. To produce the casting, the two halves of the puck are held together under pressure, then it is spun up to speed and the molten pewter is introduced in the centre of the puck. The molten metal is then thrown outwards by the spinning motion and tries to fill every void. The method produces very crisp clean castings, although I do feel they were a little crisper when they used white metal, but that is now a no-no. you pay a set-up charge for the making of the puck mould, then you are charged per 'spin' and also for the metal by weight, however the costs are not high. Link to post Share on other sites More sharing options...
craigwelsh Posted November 23, 2011 Share Posted November 23, 2011 Same system as most wm is made using in the UK from what i;ve seen. Pewter rather than the softer white metals does solder a lot easier as I found when I first used Larnarkshire models buffers. You don't lose any detail transferring the 3D print via investment casting? Link to post Share on other sites More sharing options...
Petri Sallinen Posted November 23, 2011 Share Posted November 23, 2011 The process used is called spin casting (they also do pressure casting). The spin casting is performed using a rubber 'puck' about 8 inches in diameter. There are two halves to the puck and it is made by embedding the patterns in rubber which is then vulcanised to form around the patterns. The pattersn must therefore be made of a material that can withstand the very hot vulcanising process. This is why I investment cast my 3D builds in Manganese Bronze. Geoff, I thank you for your information. The method looks like same than is using with making white metal castings. White metal casting service companies also use centricast machine with vulcanised rubber moulds (also two halves), but more typical way is using cold cure silicone for making moulds (=two components liquid style silicone rubber like making moulds for resin casting, but with white metal castings the mould rubber has to be heatproof and harder. Shore hardness of these rubbers is typically about 60 or more). Using cold cure silicone rubber for mould making means that no heat or pressure is required to make moulds. So it is possible to use plastics, resins, 3D-printings etc. materials in master parts for making moulds. It would be usefull to know if cold cure rubber was also possible to use with making pewter castings. I think that this might be easier — and maybe cheaper — with making master parts. Petri Link to post Share on other sites More sharing options...
hollywoodfoundry Posted November 23, 2011 Share Posted November 23, 2011 Yes, the process is exactly the same as for white metal casting, pewter is simply the 'new' white metal due to the need to remove lead. Zodiac used to cast white metal up until it became 'deadly'. I think zodiac don't used cold cured silicone as it is not as durable as vulcanised rubber. Craig, if you use a good investment cater, then you don't lose any detail. Unfortunately the excellent caster I used is now retiring, so I will have to find someone new. Link to post Share on other sites More sharing options...
billbedford Posted January 17, 2012 Author Share Posted January 17, 2012 Some more stuff, this time a replacement loco boiler. Link to post Share on other sites More sharing options...
simon br blue Posted January 17, 2012 Share Posted January 17, 2012 What is it printed in? FUD? The detail in the cab looks impressive. Link to post Share on other sites More sharing options...
billbedford Posted January 17, 2012 Author Share Posted January 17, 2012 Yes is was built in FUD. This one has been primed to make it visible to my camera. Link to post Share on other sites More sharing options...
hollywoodfoundry Posted January 18, 2012 Share Posted January 18, 2012 Bill, the piece looks really good, with good detail. Did you have to clean it up or sand off any stepping on the surface? Just as an aside, isn't it interesting the you have to paint the item in primer grey in order to take a good photo, somewhat like the steam locmotive manufacturers used to do for the same reason. Link to post Share on other sites More sharing options...
billbedford Posted January 18, 2012 Author Share Posted January 18, 2012 These photos were taken after the piece had been washed in hot water, to remove wax from the surface, and primed. It has since been lightly sanded with a glass fiber brush and will be primed and painted again when the weather becomes a bit warmer. Link to post Share on other sites More sharing options...
N15class Posted January 19, 2012 Share Posted January 19, 2012 The detail in these 3 D printings is great. How does it look after painting with those ridges. Large areas I take can be sanded but what about the smaller parts? Link to post Share on other sites More sharing options...
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