For the next bit, I'm gonna glue on bits of 'plasticard' and plastic tubing. I'm using 0.02 inch thick Sheet Styrene (from evergreen scale models) as well as their strip styrene 210 and 220 (0.03 and 0.035 inch diameter solid round strips. I'd have bought the same thickness, but they only had a pack of each. There are 10 strips in each pack and 3 sheets in the other.
I'm also using precision poly cement (the runny stuff that has a thin pipe to dispense it, not the thick gluey stuff.
If you want it to be like a picture cube, the centres can be anything. If you want it solved without having to muck about rotating the centres, make sure they are placed correctly and have full rotational symmetry (order 4 - like a square, not a rectangle or rhombus). I'll post some when I have done some.