(work in progress)
Working out issues with this “foot-out” portaledge concept took some time and a marriage of various new technological developments like CAD/CAM, and this post will also provide tips for other innovators.
In the meantime, see https://www.bigwalls.net/the-d4-story.html
Original 1999/2000 notes (this design didn’t really work that well—it was a hinged design and hinges in portaledges tend to result in a wobbly frame):
I was also hopeful of this design at the time:
Jeff Lowe submitted this design to A5 about 10 years before (too floppy):