Agreed. It was SteelBikers concept that was so ingenious.
I actually used a 2 inch 1/4"-20 bolt because the non threaded (smooth) section was 1-1/8" long. Using a hacksaw I cut the bolt's overall end-to-end length to 1-5/8" which left a threaded section of 3/8". Smoothed the cut with a file to remove all burrs.
I didn't have an acorn nut but I did have a nylok? nut (a 1/4-20 nut with a built-in plastic locking ring feature sometimes called an anti-vibration or aircraft nut).
I also didn't have the recommended spring but I did have one that was 5/16" diameter x 1" long made of 0.038" wire. It's a stiffer spring but was still easy enough to compress. Since the spring was a bit too short I added a washer to the outboard side where SteelBiker shows the acorn nut. It preloaded the spring just enough. Thinking about it now, I could have stretched that spring and left out the washer.
This is a fantastic workaround for the stuck key syndrome.
creakndale