Sprue detective

Have you guys actually looked at a sprue of parts? Not just looked for parts or looked to see where the flash is. I mean really take a good look at the details and art of the sprue.

Of course, older models may not have the best molding or design. But many newer models have improved molding technology and improved master molds.

Take a look at the sprue from a recent model kit and you’ll be amazed. If you know your models, everything is there: bolts, nuts, weld seams, barrel jackets, charging handles, individual tank treads, car trim and the list goes on.

To make a model kit, someone has to find a 1:1 vehicle and measure everything about it and take many photos. But the work is not over.

Next, workers make pattern models of each part, several sizes bigger than the final parts, carving them from soft wood, making sure each part fits together properly. The pattern models get covered in epoxy resin. When the resin dries, the wooden pattern models are removed and the cavity filled with resin.

These resin model parts are copied by pantograph onto steel “tools” or large pieces of metal to form the molds for the parts. Using the pantograph allows for the scaling of parts down to the final scale. The location of each piece on the tool is planned ahead of time along with the sprue and gates that guide the molten plastic.

That is a basic description of how the molds for models are made, and they might differ between companies, but that’s generally how they’re made. Read more about this process at How Products Are Made.

So remember all the work that goes into making the sprues of parts we use to assemble our models or lose in the carpet monster.