ibudmen's Catch didn't let me go. As we found it a little bit too small to catch all the ashes (and not to get knocked over by our children all the time ;-) ), I already had tried to make a bigger one in Inventor fusion (http://www.thingiverse.com/thing:224721) which was nice, but not as beautiful als the original one (http://www.thingiverse.com/thing:75477).
Now, I played around in OpenScad and made another one which is closer to the original, but about twice the size.
Catch_XL.stl | 274.4KB |