This is a very simple stackable shelf system I designed for organizing my workbench. They turned out very sturdy and the wall thickness could easily be reduced depending on shelf size.

It is easily scaled in CAD with parametric modeling. The inside height, width, depth and wall thickness can be changed. And the back wall could be removed if desired by using feature suppression in the equations table (Solidworks).

The attached stl model has internal dimensions of 7in x 5in x 2.5in and a wall thickness of .25in. (approx. 178 x 127 x 64mm and 6mm wall) No I'm not sorry for using inches :)

This shelf is printed on the back wall and requires no supports.

The pictured models were printed with 0.2mm layer height and 0.4mm nozzle and 15% infill. Printing with the speed setting produces good results as well. (At least with the Sunlu PLA + 2.0)

Update: 1/24/2026: Updated geometry to reduce warping. also, the chamfer on the back wall being removed seems to reduce warping. Either way, the shelves are still perfectly functional even when it does warp. 

Update 1/27/2026: Added files for flat top plates, interconnection top plates for when you want to stack shelves side by side, and a bottom tie plate to help keep the shelves together. All of these are also parametric. Just keep in mind that they need the dimensions to be larger to accommodate the wall thickness of the shelf, this is due to the shelf being measured by the inside dimensions

Update 1/31/2026: Updated the shelf to allow a bottom corner to be cut out on either side to allow the shelf to stack on top of the interconnect plates. Also the flat top was updated to allow the same thing. Both are adjusted in the equations by feature suppression.