I've occasionally posted my progress in this subject on another forum. It's time to bring this forum up to date.
For those who are not aware of the problem when an HG pilot wants to change from prone flying to seated or supine flying it's that the body position differences make it so that the seated pilot can't properly reach a control bar rigged for prone. The seated pilot is sitting with the upper body farther back so that the bar needs to be moved back from its prone position.
So the glider could be re-rigged for seated but then an old problem of the sitting pilots in the early days would come back. That is the pilot's weight not being able to move far enough forward, because of the base tube position, to be able to gain more glide speed. Therefore, I've been working on getting a good bar adapter design that will leave the control bar in its forward prone rigged position. My latest iteration in the design is a combination of things I've already tried, where I'm attempting to incorporate good things from those designs and eliminate the poorer aspects of those designs.
AT THIS POINT I WANT TO HEAP MANY THANKS ON MY FAITHFUL, AND MUSCLE SORE FROM THE DOCKWEILER SAND BLUFF, TEST PILOT, BOB KUCZEWSKI He along with several others have added their time and energy to helping me evaluate the results of different approaches I've taken to solve the problem. I need to add that all of things I've tried would work OK in the air and mostly on landing also. The main problem to be dealt with is in the light wind launching run.
The seated pilot sits lower than the prone pilot so a launch "touch & go" is more likely and a good running form is more critical. Some of my bar adapters did not allow the pilot to get far enough forward to get a low enough angle to get good speed at the start of the launch run. I discovered this was very dependent on the hand position on the bars. Holding vertical adapter bars does not allow the pilot to move forward of the vertical bars so it became obvious that the launching pilot needs to be holding something that is more or less horizontal until in the air. Once in the air, then the vertical bars are best for flying control but if you need to "belly up to the bar", then the horizontal bars come in handy or reach through the adapter bars and hold the glider's control bar uprights.
In the photos I've posted are the various approaches I've tried. The one I call "U" shaped is similar to the Northwing tow pilot adapter. The latest design is the one where the bars angle in toward the base tube. This design has not been flown yet but attempts to combine a horizontal handle bar and vertical bars that go high enough to allow the shoulders to push against them at the start of a launch. That was a problem with the "U" shaped bars. The angle at the bottom allows clearance from the ground when the glider is parked and more room for the pilot's knees to rotate around in the swing seat. It also reduces material used. This adapter can be installed or removed in one minute each, without tools.
I reiterate, this latest approach has not been flown as of November 14, 2020
Frank Colver