Easy $35 Sailplane Stand
I began by forming two 3" x 3" x 6" blocks out of flexible packing foam. The foam I had was only 1" thick so I glued three layers of it together for each block, using 3M spray adhesive. Then I wrapped the sides and top of each block with black duct tape, glued the blocks to the top of the work support with 3M adhesive, and secured them further by wrapping duct tape around the blocks and work support top.
The support comes with a removable pin to allow tilting the top to a 45 degree angle, but that makes the top loose and unstable. I added washers, tightened the swivel bolts, and replaced the removable pin with a nut and bolt to make the top solid.
I added two small bungee cords, about 1/4" thick and 12" long, to hold down the fuselage at the front and rear of the wing.
I drilled four small holes in the bottom of the work support top, spaced 3" apart, and permanently attached each bungee cord at one end while using a keyring at the other end to make it easy to attach and release.
The stand folds up to a compact size, making it easy to transport...
... but extends to a perfect height for assembling the plane at the field.
After the stand is set up, the sailplane's center wing panel is attached to the fuselage and then the assembly is mounted on the stand.
The front and rear bungee straps are wrapped around the fuselage.
The plane and stand are very stable even with only one wingtip attached.
The foam blocks are short enough that the flaps are clear and can move freely. All the control surfaces are free and can be adjusted while the plane is mounted on the stand.
The stand is heavy enough to prevent tipping over in normal wind, but in stronger wind it can be lowered for extra stability.
Here's an added latch that attaches to the launch hook so that you don't need to wrap a bungee cord around the fuselage:
Jody Miller used wider foam blocks and narrowed the space between them to grip the fuselage and keep his plane from swiveling in the wind: