I have made the two wheeler which works perfectly. Obviously there are bits of post-printing work to be done but well worth the effort. I did have an issue with the tipper which I printed as instructed with 100% infill. The weight of the 4 marbles was not sufficient to tip and I had to drill out the tipper counter weight.
Overall, I am very impressed with the two wheeler and am now starting to print the bucket tower.
The idea of being able to change the modules is very cleaver and I look forward to seeing different modules becoming available.
I believe that Luka is promising a "bigger, better and brighter" design and I am looking forward to seeing that