I can make a winged sonobe cube and the winged sonobe piece. I learnt to do this from our origami book. The book states you can use twelve pieces to make an octahedron.
We have spent quite some time trying to puzzle out how to do this without success. I then tried to google a tutorial but can only find tutorials for the normal sonobe piece octahedrons.
Does anyone know how to build an octahedron from the winged sonobe pieces?
Image is mine. I took it for this answer.
As you have stated you can make a cube expect you can get to the point with the three pieces together.
Which for me shows where to put the next 6. Is the adding the last 3 units the point where you get stuck?
If so i find assembling the last three pieces together and then putting them in easier.