Bend It Like an Expert30 Nov, 2003 By: Andy Wendt
How to create sheet-metal flat patterns in AutoCAD.
Few CAD users seem to know how to create a sheet-metal flat pattern with proper bend allowance. Except for those that use 3D CAD software that automatically creates sheet-metal flat patterns, most companies have their engineering departments create a dimensioned drawing of formed sheet-metal parts and leave the flat-pattern calculations to the shop.
The manufacturing trend for sheet-metal parts, especially for prototypes and small production runs, is to use computer-controlled laser or water-jet cutting machines. These precision machines cut with outstanding accuracy, and they can import CAD geometry for a cutting pattern.
I formulated a method to produce accurate sheet-metal flat patterns using AutoCAD to perform the calculations while constructing geometry. This method is ideal for small production runs of accurately cut and formed parts without a custom-made die. However, it works for any sheet-metal flat pattern, even if total precision isn't needed.