I was in DIY mode today and came up with something simple, functional and relatively easy to fabricate.
I have the aluminum cold shoe's coming tomorrow to replace the scrappy parts I used to prototype my bracket. Once I complete assembly and paint it I'll show some images.
I was going to make it to accommodate a flash with the head rotated vertically but I'll save that for another version if I find I need it.
My primary reason for wanting this bracket/adapter was to be able to use a Speedlight inside an octabox. I'm currently able to fire in to a 24" x 32" softbox and although I have not taken critical measurements I find the light to be fairly even. I know that in an octabox I won't get completely even light but that's ok. I'm willing to accept and work with that in order to have round catch lights when I work outside. To me, it doesn't make sense to be shooting outside during the day and have square catch lights. In the studio I'm fine with it.
Anyway, the bracket I made took a different approach than most. There is no need to attach any hardware to the actual speed ring. I'm taking advantage of the umbrella mounting hole.
What I did was simple. I'm using a 1/2" aluminum rod inserted in to the umbrella mounting hole, with a dimple placed so that when you tighten the thrumbscrew it locks the rod in place so it can't spin or rotate.
I flattened a portion of the rod and mounted a strip of aluminum to it with a cold shoe mounted for the flash, and a second cold shoe a few inches behind it for a Pocket Wizard. Initially I thought that having the PW behind it would block the controls and display but that's not the case. I can still see and operate the controls with no problem.
Once I have pictures this will all make sense but it's quite simple, strong, effective an much better than a single bracket that holds and suspends the flash, speed ring and modifier, and this is also much better than the flimsy flash bracket kits currently being sold.
My design includes the use of a Bogen 2905 umbrella swivel bracket. I haven't tested it with other brackets so the height and position may change. No guarantees of any kind other than with the Bogen bracket.
I'll have images tomorrow.