Thousands of tutorials to learn from
Steps
1 new sketch draw circle on plane for outside diameter
2 new sketch draw circle on plane for inside diameter
3 Draw helix using outside diameter (1 revolution or less)
4 Draw helix using inside diameter (1 revolution or less)
5 new 3D skech convety entities outside helix
6 new 3D skech convety entities inside helix
7 Sheetmetal loft between two 3D sketchesMore than one revolution in the helix will not let you flatten pattern