Edge bending
Quotes are verbatim and attributed to their original authors.
Steel edges are straight as supplied and must be bent to the tip and tail radius before layup so they follow the shovel. Doing it cleanly — a smooth curve without twisting the edge — is one of the more finicky steps, and the forum's builders converged on a few good tools.
By hand versus a roller
Hand-bending around a form works but is slow and inconsistent. A three-roll bender turns it into a quick, repeatable operation: "with a three rolls edge bender you can bend the edges for one ski in a few seconds" (davide, #378).
The Harbor Freight ring-roller modification
The most-copied home tool is a cheap ring roller re-machined to grip an edge.
Pre-bent edges
Some edge manufacturers will sell pre-bent edges, but the minimum orders are industrial — one builder was quoted a minimum "of about 65 kilometers," so this only suits large producers. Suppliers such as CDW were mentioned as offering the service in smaller quantities.
Going CNC
A powered, CNC edge bender was prototyped on the forum. The key design lesson was roller geometry — bottom rollers close together and small in diameter need far less force to feed and bend the edge. The hard problem is feeding:
Proposed fixes included cutting a deeper groove with a rubber ring for grip, and a toothed centre roller that meshes with the edge teeth — though at tight tip radii the teeth close up and a sprocket no longer fits.