Spin Casting – The Basics
You need five basic elements to spin cast metal miniatures:
- Centrifugal Force
You need rubber to create your mold cavities, and metal to fill those cavities. Heat and pressure makes your mold. Pressure, heat, and centrifugal force allows you to get your metal into the mold cavities.
Most tabletop games miniatures are made with pewter and organic rubber molds.
Rubber mold blanks are placed into a frame that maintains the shape of the mold and allows you to apply heat and pressure. The rubber melts, flows around the miniatures, and then hardens. A layer of mold release keeps the two halves from sticking together so you can pull the mold apart and remove your casts.
A hole in the top half of the mold allows you to pour molten metal into the mold while it is being spun, and the centrifugal force of the spinning causes the molten metal to flow from the center of the mold into the cavities. As the metal cools, it solidifies, and you have new miniatures.
That’s basically it. You can get a lot of fancy equipment to do all of that, but you can also get it done with most anything that can apply the appropriate forces. You need about 2,000 pounds of pressure on a mold and 250-350 degrees Fahrenheit to cook it properly. Your pewter needs to be at about 500 degrees for casting, the mold should have anywhere from 10 to 30 pounds of pressure on it to keep the two halves from separating, and it needs to spin at upwards of 500 RPMs.
Josh Qualtieri (ZombieSmith Studios), for example, scratch built his first spin caster out of old washing machine parts, and vulcanized molds in his oven with a scrap metal frame and some clamps. That said, $3,000 will get you a second hand professional setup, you can get a spiffy new one for as little as $6,000, and you can drop more than $10,000 on a high-end basic setup if you’ve got way more money than you need.
Over the next few months we will walk you through the spin casting process end to end, in more detail that you probably give a shit about. We’ll have plenty videos as well, for those of you who prefer to watch crap on Youtube. But the new computer isn’t in yet, and I don’t have time to wait 6 hours for a video to render on my laptop, so you’ve gotta wait, okay.