Inspired by the recently posted video and build instructions here on Eurobricks for Akiyuki's Ball Factory, I have reverse engineered Akiyuki's Cup-to-Cup GBC. It has been built with parts which I had available at the time, so it is a mixture of colours at the moment;
The next steps are
1) model it using MLCAD to produce an appropriate LDraw file
2) use BrickLink to obtain the appropriate parts (to reduce the colour mixture)
3) create build instructions using LPub and test them using the parts bought in step 2
4) make the build instructions available for others
It will likely be a few weeks before I get to step 4 but once I get there, I will post appropriate links in this topic.
Regards,
David