Sheet metal unfolder for AutoCAD (no need of DXF convertions) - Shareware $48. LITIO is a sheet metal program that calculates flat (unfolded) sheet development of ducts, rectangle to round transitions, cylinders, cones, pipe intersections, connections, bifurcations, elbows, etc. For HVAC, hoppers, cyclones, dust extraction, ducts, conveying systems, silos, piping, etc. To draw your sheet metal developments directly in AutoCAD R2000 and later (no need of DXF convertions).

Steps of use: First select the 3D surface you want to unfold. (You can select: either inside, outside, or mid cross sectional dimensions and/or height specifications; to draw or not the 3D surface, and the unfolded sheet as a mesh [to help you when bending the sheet] or as 2D contour [to ease cutting]; the precision of the calculation of the developments). Metric Units/Imperial units: the program automatically sets the units according to the units used in the current drawing session. After finishing the input of parameters, the program draws the 3D object and the respective development. Afterwards, you can use the 2D developments for CAM cutting (plasma, laser, etc.) or manual cutting, by plotting them 1 to 1 (1 d.u. = 1 mm or 1 d.u. = 1 inch), and using them to mark sheet and cut.