Thermwood Patents Internal Bracing for Large Cut Layer Molds

Thermwood has patented a method for stiffening large hollow molds built from stacked, machined sheets. The technique, detailed in US Patent 12214528, adds small protruding anchor points to selected layers during the cutting process. Support members then span between those points inside the cavity, reinforcing the structure without wasting material.

This is not conventional 3D printing. Thermwood's cut-layer process cuts individual sheets on a CNC router, nests the pieces for efficiency, then stacks and bonds them. The result looks like a solid block once machined, but it is actually a shell. For very large molds, that shell can flex or vibrate during use. Internal bracing solves that without filling the whole interior with expensive aluminum or steel.

The patent describes a controller that can automatically place anchor points where stress analysis says they are needed. Support material does not have to match the shell. Thermwood suggests using different metals, composites, or even 3D-printed inserts. The system could span rods between points, stack supports across layers, or cross-brace the interior like a truss.

Large-format additive manufacturing usually focuses on printing faster or with better materials. Thermwood is asking a different question: what if the best way to make a huge tool is not to print it at all, but to cut it from sheets and brace it intelligently? The patent does not require new hardware, just smarter software that understands where stiffness matters.