In plastic model kit molding, the sprue is essential for directing molten plastic from the injection molding machine into each cavity of the mold where individual kit parts are formed. It acts as the main pathway, allowing the plastic to flow efficiently and uniformly, which is key to ensuring each piece fills completely without defects like voids or air bubbles. By delivering just the right amount of plastic to each cavity, the sprue helps minimize material waste, an important consideration when producing intricate model kits with multiple small parts.
Once the plastic has cooled, the sprue and attached parts solidify as a single unit that can be easily ejected from the mold. This design benefits both production and assembly, as hobbyists can identify and separate parts themselves during assembly. The sprue also helps maintain the consistent temperature and pressure required to fill each cavity accurately, ensuring uniform part quality and the fine detail expected in model kits.
In addition, sprues organize and stabilize delicate parts, making it easier to handle, inspect, and package them for model kits. This not only keeps components in order but also reduces the risk of misplacement before assembly.
The thing is, to use sprue means you need to design the whole set as one single file. Most software cannot automatically arrange smaller designs into one set for you. For starters this would be a bit more complicated. Therefore we would advise you to first start with a single part design without sprue first.
