Assemble as per "Assembly.skp", a Sketchup 8 (free version) file.
All parts slide together except the letters, which were attached using cyanoacrylate in a somewhat haphazard fashion. In any case, make sure the word "Year!" clears the bottom of the cam stroke!
Depending on the colors and type of plastic you chose (PLA or ABS), you may need to sand, scrape, file, etc., and/or glue the parts in position. With white and black, I found that a medium amount of sanding, scraping and filing was required. With white and orange, the parts slid together without very small additional work. Most importantly, the lifters must slide freely in the guide columns and the axle caps must turn freely within the holes in the base. If yours do not, sand, scrape and/or file as required to obtain a free sliding / rotational motion.
Questions? Comment, and I'll do my best to answer.