This tiny module from Akiyuki is so cute! Made with a limited number of bricks, this GBC module is one of the first Akiyuki videos published on his channel and is for sure an excellent module to start with. Simple does not mean bad: the mechanism is just clever and the balls are reaching the top of the structure in such a smooth way.
| Original design by: Akiyuki | Number of parts: 453 |
| Original Blog Article (Japanese): here |
Complexity for building:  |
| Price for Building: €, cheap |
 | Download LDD Building Instructions |
LXF file provided by DutchtreatNL LXF file 2 provided by DutchtreatNL |
 | Download LDraw Building Instructions |
MPD file provided by David Julian Manley MPD file 2 provided by Courbet |
 | Download PDF Building Instructions |
PDF file provided by David Julian Manley (Additional Inputs from djm) PDF file 2 provided by Courbet Related to MPD file 2 from Courbet (version 2 of the module) |
 | Building Instructions, parts list and more available on Rebrickable | LEGO Set MOC-5123 – Akiyuki”s Zigzag Stairs GBC provided by David Julian Manley |
We do NOT recommend v1 of this design.
It falls to bits!
We built V2. Works like a charm.
hello jasperv78,
indeed, you are not the first one to report issue on the building instructions for this module. But I know that the EuroBricks forum community is working on a workaround (link is here: http://www.eurobricks.com/forum/index.php?/forums/topic/117305-gbc-the-akiyuki-project/&do=findComment&comment=2592659 (you have to browse the posts))
DutchtreatNL also reported equivalent issue to me:
“On Page 11, 2 lbley Axles 5 and 2 black Axles 6 are being used, which should be constructed like the popout picture. After that, the lbley axle is connected to a “Technic, Axle and Pin Connector Angled #1”.
The height of both axles look the same from the instructions and also the ldraw file.
However, I don’t think this is possible and the black and lbley axles should be switched.”
For your investigations, you can inspire yourself from V2 version of the module designed by Courbet. This one is proven to be reliable.
Thank you very much for this fast reply. I felt pretty stupid not being able to create this not-too-difficult module, but luckily I’m not that bad… 😅
When following the Manley instruction, the mechanism is not working. Instruction 7&8 seem the issue to me, fitting the parts in 8 does not work. When swapping the pins such that it does fit, the cross bars keep blocking a full rotation. Will try to solve it by a slightly different approach