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home metal casting a miniture car grill
Mr Whippy - 28/12/12 at 09:59 AM

Hi

Wondering if anyone can help with this or has done similar with low temp metals

I want to make a miniature of this grill around 30 cm wide in metal, plan is to make a replica in wood that a silicone mould is then made from it. Then cast the grill with some reasonably strong low temp metal, aluminum I think is too hot to use but has anyone used something that would be easier? Needs to be about as strong as aluminium just easier to pour and cast. Not keen on sandcasting as that has been hit or miss in the past well more miss than anything...

Not really made any measurements but I recon it would weight about 1/2kg all up

Any ideas? ta

Oh and had thought about rapid prototyping one in a structural plastic if the cost was not too great as I can get a 3D model easy enough, wish I had a machine myself one day




[Edited on 28/12/12 by Mr Whippy]


rf900rush - 28/12/12 at 10:52 AM

What about the new wave of DIY 3D printing machines that use ABS.


ReMan - 28/12/12 at 10:58 AM

That a lot of small detail in that mesh, tha i would have thought wold be difficult with any amature open casting method and would require a pressure casting method. (from dim and distant engineering training)!


Mr Whippy - 28/12/12 at 11:07 AM

not sure tbh I thought of casting it vertically with the silicon mould in a box so the metal ran down all the grill slats, but yeah quite a bit of detail but not any more than say metal toy solders? If I could find a suitable metal I could try some experiments

The rapid prototyping looks really good but I think it would be hundreds of pounds for something like this? So far I can’t even find prices, they just offer to give a quote. Anyone used a company?


ReMan - 28/12/12 at 11:11 AM

Has it got to be metal?
If it's for a "toy" could you vac form silver plastic for effect?


hughpinder - 28/12/12 at 11:30 AM

I've cast aluminium various ways - pure aly (and most alloys - Ive done 6082 and 5053 the same way) can be easily melted with a good blowtorch (a roofers torch and propane bottle work best) in a cheap stainless steel measuring jug and lift with mole grips (about £4 from Tescos) (I usually preheat on the barbeque to save gas). Drop a polystyrene bead in every now and again to form an inert gas layer and reduce oxidation. You will also need some fort of scraper/stirrer. I doubt that you can cast the very thin wires - the metal will cool too much in the very thin runners to make it more than an inch down one of them (toy soldiers dont usually have very long very thin bits) You may be better off casting the thicker outer bit and glueing wire mesh on the back.
Best of luck
Hugh


trextr7monkey - 28/12/12 at 11:34 AM

Hi Whipster,
Pewter might be the way forward but the mesh might be a problem - could you cast frame then insert fine mesh behind as a seperate assembly?
We invested in a small ultra safe child friendly pewter kiln a while back ( checkout "Flamefast" - lots of tips there too) to interest girls in jewellery making- it is about £30 a kg and goes a long way, so far we have only made small stuff but lots of ideas for moulds are about - we use photo mounting boards sandwiches where the item to be cast makes up the middle layer with a sheet either side which allows stuff thin enough for pendants and earrings to be made.

Could you not just CNC machine it out of wood/ board then spray?
Another way would be to CNC the frame then use it as a trapped Vac forming mould with silver plastic as Reman suggests
hth
Mike


TimC - 28/12/12 at 12:13 PM

What about buying a Rocky Mountain Grill for the S3 and hence making it much easier to copy?


trikerneil - 28/12/12 at 02:38 PM

How about Woods metal (cerrobend)? has a melting point of 70 degrees C.

HTH

Neil