Casting detailed 15mm

[NateD]

I've been sculpting miniatures in roughly 1/2 inch scale for an RPG, and I'd like to start to cast them so I can get an army out of 1 sculpt. Problem is, I can't seem to figure out how I'd deal with some of the tiny appendages. I don't think I can get away with doing a pour cast. What methods would be able to cast this in resin?

[RageofAchilles]

Hi,
I think you might be better off with white metal casting for these guys. Resin would be very brittle , plus you would need a Vacuum/Pressure setup to get the best out of resin.

While you can get very fine details with a gravity cast in white metal, spin casting would be your best bet. I first got into casting with white metal and some of the parts wee very fine, venting and having a warm mould to pour into were key.

The other good thing about white metal, is there is no wastage. Any miscasts damages and cut off sprues are re-used.

I would really recommend watching this video on youtube, very informative.
https://www.youtube.com/watch?v=IYVIVzCmH10

[NateD]

Thanks, RageofAchilles! I'll check these out!

If anyone else has an idea on how to best reproduce these (in any material) please chime in!

[mangozac]

As RoA has suggested, the only way to produce such fine parts in resin is using a vacuum and pressure technique. I personally don't have a problem with the idea of them being resin, so long as it's a lower hardness product so that they are less brittle. Forge World used to produce insanely finely detailed 10mm miniatures in resin (although admittedly they are quite fragile).

Most of the figures could be done as a single piece, although your four-armed guy not so much.

Were you set on doing the casting yourself or are you happy to find someone else to do it on commission?

[NateD]

I'd like to do it myself. The long term goal is to sculpt and cast game pieces for a game I'm trying to produce. Right now, it's just a hobby, though.

[NateD]

Has anyone tried making a centrifuge (I think that's what it's called?) that uses more typically shaped molds? I suspect it would work by having a square mold attached to a small arm that would channel the metal to the mold. I feel I could make that much easier than the circular mold system in that video (although the circular mold does clearly have many advantages, so... someday, maybe.)
Also, would this same system not work with resin?

[RageofAchilles]

If casting in white metal it isn't absolutely necessary to have a spincaster, it simply improves your chances of getting good results and allows for faster production.

Your idea of a custom centrifuge could work, but if your going to do that you might as well be making round mould for spincasting anyway. Stick to small gravity pour moulds to start with, they are certainly adequate for metal casting until you get more seriously involved.

Just be sure that the rubber you buy can handle the melt temp of your metal , this can range between 99oc - 325oc high lead alloys are low melt, especially with high levels of bismuth added, if you don't want any lead then a lead free pewter will be your best option but the melt temp will be much higher than most commercially sold rubbers can handle.

[mangozac]

The problem with using rectangular moulds in a centrifuge is that you end up with a massively eccentric weight which causes stability problems. You would have to offset with a similarly weighted mould or balance on the opposite side and even then, as I understand it, it's difficult to have perfectly balanced.

Spin casting resin does not work as well as with metal. The centripetal force isn't as effective as 50PSI+ of pressure. The only advantage is speed.