The Van Norman number 570 "automatic rotary broach" is an automotive machine shop milling machine (surfacer) used for resurfacing the flat surfaces of engine blocks, cylinder heads, and manifolds.
While it is named a "rotary broach," its operation is closer to milling or fly-cutting, not traditional keyway broaching. The machine uses a large-diameter (14-inch) cutter head with carbide-tipped inserts to shave a surface flat in one semi-automatic pass, a process that was traditionally referred to as broaching in the automotive industry. It is designed for dry cutting and is prized for producing a consistent 80-90 micro finish on cast iron and aluminum parts. Key features and function:
Function: To machine flat surfaces on automotive engine components (heads, blocks, manifolds).
Operation: The cutter head rotates, and the work table automatically traverses the workpiece past the cutter, removing material in a single pass.
Efficiency: It is known for fast set-up times and a quick cutting process, capable of resurfacing a cylinder head in six to eight minutes.
Design: It operates with the workpiece positioned above the cutter, which helps prevent contamination from metal chips and coolant.
