Provided herein is a wind turbine blade mold system having built in precision pins to locate structural components (e.g. spar caps) during layup of composite segments. A plurality of pins can be inserted through the layers of composite layups and into apertures within the mold, with spar caps positioned against the pins to ensure precise positioning, thereby preventing/inhibiting movement of the spar cap relative to the mold. A plurality of pins can be inserted through the layers of composite layups and into apertures within the mold, with cams attached to the pins and moveable to engage spar caps to ensure precise positioning of the spar cap, as well as preventing any drift during subsequent operations. The pins can remain embedded within the final molded part.