A method of cutting sheet metal material, the method comprising the steps of:
- providing a cutting assembly riding on a guide track mounted at an output location of a sheet metal working tool wherein the sheet metal working tool clamps the sheet metal at an output of the sheet metal working tool, the cutter assembly having upper and lower sections, wherein the upper and lower sections have an offset attachment to each other at an interface, in order to allow the sheet metal material to pass an offset of the offset attachment after cutting in an extended bypass cutting operation;
- and
- using a curved profile at the interface and providing a profile difference to deflect the sheet metal material on at least one side of a cutting direction in the extended bypass cutting operation,
- further comprising the step of providing the cutter assembly with two pairs of opposing cutting wheels, whereby the deflection of the sheet metal material also allows the sheet metal material to clear a lagging pair of the two pairs of opposing cutting wheels, with the lagging pair not in use for cutting during the extended bypass cutting operation, so that after the extended bypass cutting operation, the cutter assembly has a position allowing performing a subsequent bypass operation in an opposite cutting direction, with the previously lagging pair of the two pairs of opposing cutting wheels becoming the leading pair of cutting wheels and cutting the sheet metal material in the subsequent extended bypass cutting operation,
- wherein the guide track has a mounting configuration allowing mounting the guide track to a sheet metal forming tool with said cutter assembly riding on the guide track,
- wherein, the deflection on said side of the cut in which the sheet metal forming tool had created or changed a profile in the sheet material exceeds the deflection downstream of the cutting head, so that the working tool can progressively discharge worked sheet metal past the cutter assembly, and the major deflection can occur on the side of the cutter assembly that faces the sheet metal working tool,
- and wherein the interface has a differentiation in its profile, the differentiation comprising the curved profile and at least one additional profile, the differentiation causing a differential deflection in the sheet metal downstream of the cut as the cutting assembly rides on the guide track, so that the deflection falls well within the elastic deformation limits of the sheet metal formed into non-flat shapes and not easily deflected without damage, thereby allowing bypass cutting of sheet metal in a manner that reduces distortion of the sheet metal on a side of the cut in which the sheet metal forming tool had created or changed a profile in the sheet material, so as to not damage a non-flat shape of the formed side of the work.