I was looking at Crazybadcuber's video
on how to make a half proportional 3x3x5 by moving the top layers between a c4u 3x3x4 and 3x3x5. In his video the corner and edge pieces can be changed, but he sands down the centre caps to make them match and then glues them on.
But I thought that rather than sand down the caps, you should be able to unscrew them and swap them also. And then I thought that I could then put the spare pieces back onto the other cube and end up with two new cubes instead of one. So I started with these:
File comment: Starting cubes
cubes_3x3x5_3x3x4.jpg [ 219.63 KiB | Viewed 1192 times ]
And ended up with these:
File comment: End cubes
cubes_3x3x4_3x3x5.jpg [ 219.39 KiB | Viewed 1192 times ]
The 3x3x5 shape changes like a fully functional 3x3x5. Both are very smooth turning, although the 3x3x5 is the better of the two.
PS When I returned to get the link for the video, I noticed that someone has commented that you can just swap the caps like I did, rather than sanding them. But no mention was made of making the second cube as well.
PPS I searched for these ideas on the museum and this forum, but I couldn't find them anywhere. Apologies if I missed them.
PPS I suppose you could also swap parts between these and the centre edges of a c4u 3x3x9 as well?