This is a remix of SalsaVerdeByTheGlass's awesome “Rack for BFS - 20 Bin”, and is fully compatible with the original source design.

Use superglue when assembling the two halves of each tier, which connect with dovetail shaped tabs.

This design builds on the original with sizes for 9U and 12U cases.

I also included some other extras:

1. Extenders to add 4U or 6U to the height of a tier, without needing to reprint the whole thing.  These are the Green and Red parts in the above image.  These extenders are not tested, but the design has been checked out in CAD and the slider (feedback welcome).
2. Wall clips to help secure a tall stack to a wall (not for hanging a rack on a wall).  These are available in 2 types, one uses large 3M Command Strips, and the other uses #8 wood screws.  There is also a thicker version of both designs, in case the rack is not tight to the wall (the thicker design adds 1.5mm to move the clips that much further from the wall.  The wall clips are not designed to support a rack hung from a wall, I used them to stabilize a tall stack or racks which was sitting on a shelf.  

I have installed the 6U, 9U and 12U rack tiers, and they work with the similar size Gridfinity Cases (linked below).  I built a shelf of 10 tiers using a mix of these racks and the racks from the remix source, and it is very sturdy.  My boxes however don't have much in them currently, so I do not know how much weight it will support.  I installed the wall clips at the base and also near the top, to help stabilize my 10 tier tall rack (I used the 3M Command Strip versions).  The wall clips will not fully support a rack hung on a wall however.  I used the wall clip to help support a tall stack of tiers that was sitting on a shelf.  Use your best judgement on how or when to use the wall clips.  

I did not test the 4U and 6U extensions, but there was nothing that appeared to interfere and the design for those parts is very simple.  Feedback is welcome as always.

Parts:

• Each tier of the rack will require (4) M3x10mm SHCS.
• The wall clips will require either (2) Large 3M Command Strips, or (2) #8 pan head wood screws

If you want to check out my other Gridfinity cases, you can find them at the links below:

1. Gridfinity Box For Stuff 20 bin (6U)
2. Gridfinity Box For Stuff 25 bin (6U) (max size for a Bambu X1C/P1S)
3. Gridfinity Box For Stuff 16 bin (6U) (Ender 3 size)
4. Gridfinity Box For Stuff 16 bin - 12U deep version (Ender 3 size)
5. Gridfinity Box For Stuff 2 bin (6U) (small test version)

Additionally, there are some alternate latch parts which may help if you do not have the M3x30mm screws or have difficulty installing the latch “cleat”.

Other stuff:

If you need some bins for small parts, the following bins with covers are a good option to use with the Box For Stuff 20 bin and 25 bin cases (or other 6U tall cases):

1. 1 compartment 2x1 (3U, 6U, 9U) bin with a magnet pickup tool
2. 1x1, 1x2 (3 Compartment) and 1x4 (6Compartment) bins with lids (6U) - version 2.1
3. 1x2, 1x3, 1x4 (6U, 9U and 12U) Lidded Bin for Stuff with Latch Version 2.0
4. 2x2, 2x3, 2x4 (6U, 9U and 12U) Lidded Bin for Stuff with Latch Version 2.0
5. 3x3, 3x4 (6U, 9U and 12U) Lidded Bin for Stuff with Latch Version 2.0
6. 4x4, 4x5 (6U, 9U and 12U) Lidded Bin for Stuff with Latch Version 2.0

If you find these models useful, please post a like or a comment with some pics of your prints.

You can find the other things I'm working on at my blog here. You can also follow me here or on Printables to see what new stuff I post. If you would like to support my work, you can Buy Me A Coffee using this link:

https://www.buymeacoffee.com/mystoopidstuff

Thanks for looking!