"Troll forge spincasting plastic miniatures" Topic

Here the link:
link

Seems they develop a sort of technology, don't know if the difference is in the mould material or in the liquid plastic or in the spincasting mechanics but I'm really curios about.

is not possible cast polystyrene with spincasting? This will be a great solution IMHO, polystyrene can be melted more time like metal (resin no) and is really inexpensive.

Injection molding is normally used for plastics. Spincasting is normally used for metals. Spincasting with plastics may be a revival of an older technique for plastics but is definitely not the norm for modern plastics manufacturing.

Why did you link to a comment, ya melon?

Ed's been at this a while, and while I haven't kept up too closely, I've seen some of his test results over the months and they look brilliant. Think more about Reaper's new Bones range than Finecast; though that's not to say it's the same.

Even so, he's been tweaking something in the mix and process for a while, and keeping pretty quiet about it. AFAIK there's no polystyrene in it, but I've heard him talk about ABS a couple of times.

And polystyrene plastics are usually cast this way:

link

… with steel moulds costing thousands of your transatlantic currency of choice. What with the rise in the price of tin and the shift towards injection moulding by those mini companies who can afford or recoup it, there's been a fair bit of interest in casting tough, cheap plastic on the smaller, more affordable spincasting scale.

But I'm just parroting what little I know. Wait 'til an honest-to-goodness mouldmaker and caster turns up here.

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Warren B.
minisculpture.co.uk

I guess I'm pretty ignorant, but I thought this was the way plastics were cast. They certainly aren't gravity cast, are they?

My understanding is that typical injection moulding machine uses high pressure to force the (liquid) polystyrene to the mould to fill it properly.

Thus no need to apply spin to make the plastic flow better into the mould.

I would think that if you could combine injection and spin casting that you might really have something there.

This can be a great solution.

But why cannot try polystyrene on a spincast machine? Is too dense?

Some month ago a moulds reseller tell me resin is not good with the usual rubber moulds because the chemical substance in liquid resin damage shortly the mould during the catalysis. Also, the great problem with spincast and resin is the great quantity of resin wasted in mould ducts, when work with metal the mould ducts can be recycled fast (take it and put on your melting pot). Polystyrene will resolve this problem, because, if I'm not wrong, the polystyrene can be melted again like metal.

Now, I would like to know if someone tested polystyrene

Baggy@ combining spin cast and pressure injection? Seems impossible to me.

There are a number of spin castable plastics on the market

I am currently in discussion with the provider of one.

The wastage is what is getting me down, as everything that I currently cast in metal all of the other material that fills the voids in the mould can be re used, the spin cast plastic cannot, and is wastage, and at current cost from my supplier it looks like about the same cost overall. (the material is very like fine cast. but more plastic like)

I am pretty certain you cannot spin cast polystyrene.

Hi Maddaz111,
but what type of plastic they use in spicasting? ABS? is it like Prevateer Plastic? Or like Reaper Bone line?

Agree wastage is a big issue in spincast.

Why cannot use polystyrene? The only issue I can think is about quickly cools.

Its Finecast, pretty much all the stuff we call resin are forms of plastic. There is a huge diversity of material.

Yes, I know, all plastic are sort of resin and, so, all resin can be called plastic.

In the link I posted previously, I found this comment:

We [games workshop] tested spin casting polystyrene pellets at GW for several years (when I worked for them) with some success but kept going back to a resin type mixture, not actual polystyrene by itself. Unfortunately the testing stopped when our mold room manager left to work for PP and took all the info he was working on with him. I'm not sure what he does for them but it wouldn't surprise me if they came out with something similar soon.

So, seems finecast is practically spincast of liquid resin. They also test polystyrene on spincast, and I'm curios about the result. Polystyrene is IMHO the best medium: can be recycled (so no wastage in your mould), is rigid (so no twisted blade), is light and can be worked fast and easy for conversion.

Seems a mixture of polystyrene with other product (Ed say no PVC in it).

Perhaps it would be a good idea to understand the different materials and the terminology. This link gives a good description of what most people mean when they say "plastic", and following the link to this link describes what most people mean when they talk about "resin". The fundamental difference is that "resin" under goes an irreversible chemical change on curing, where as, when heated, "plastics" do not. That's why you can reuse waste "plastic" but not waste "resin".

New type of casting material are the future for our little market. Metal becoming too expensive (and don't forgot shipping cost increased a lot in the last years, and metal weight is counterproductive)

Hope some company release some "restic" formula in a near future.

Another point like very much about trollforge figures is the total (or not visible) amount of mould lines.