UPDATE: I added a second version. The flash tube is not in the center of the youngnuo, so I moved the flash up 4mm. Now the lighting is more evenly - and now it also works with the zoom-lens.
Instead of a torch you can mount a flashlight to the gbeam. This adapter is for the youngnuo-yn560.
As with the "originals" you have to use adhesive tape to fix it.
It works well with a 35 mm or 50 mm lens. With a zoom (80 - 200 mm) the lower part of the picture was to dark (with the first version).
35 mm or 50 mm means, that the projection will be quite big on a short distance. That´s good for indoor use - for example projecting interesting backgrounds while shooting pictures.
Printed well without support.
Freecad-file added to make changes if needed.
Set the "zoom" to 105 mm on the flash.