Bridge mills and gantry mills share the same silhouette, but the difference that matters is what moves during the cut. On a bridge mill the workpiece rides a table that travels beneath a fixed, double column bridge, a closed structure stiff enough to own tight tolerance die, mold, and precision work. On a gantry mill the part stays put and the gantry travels over it, so the machine can swallow the largest, heaviest workpieces and run travels measured in tens of feet. Part weight, floor space, travel, and accuracy all follow from that one fact.
Drawn from Resell CNC's hands on experience buying, selling, and appraising large format equipment since 2008, this guide shows you how to match the machine to your parts and what to inspect before you buy.