This openscad code generates stackable trays with any width/length, and equal size divided sections in rows and columns. It is customizable in most dimensions.

The key to the model is a “lean” value calculated from the height and thickness of the outside wall, with an added factor for easy stacking, and a “lip” on the outer wall that will grip the bottom of the tray on top.

The included models are for relatively specific purposes:

The pencil tray is (roughly) half the width and length of an Ikea drawer, and the correct depth to hold pencils, colored pencils, and water color pencils. The Prismacolor marker and dry erase marker trays are the same length/width as the pencil tray (they can stack with each other in any order), but with 16mm depth for the Prismacolor tray, and 19mm depth for dry erase markers.

The snack organizers are intended to fit in a cabinet, and hold different snack items, fruit cups, bags of peanuts, granola bars, etc. The size I printed was limited by the size of my printer. If you have the capacity for it, make a tray the full depth of your cabinets.

Printing Notes:

No supports are needed.

Any bed adhesion issues are going to show up on the resulting print (The blue snack tray in my pictures suffered this fate). A brim can be helpful to fight this, along with all the usual tips (clean print bed, adhesive layer, higher bed temperature, choice of filament, etc).

Customization:

Very thick walls, or very shallow trays will cause the lean value to grow very high, and eventually produce a not very useful tray. Set the floor thickness based mostly on the weight of the items the tray will hold. Set the wall thickness based mostly on the weight of all the trays you plan to have above.

Very large and thin walled trays will be too prone to buckling. Thicker walls, and interior dividers can help. The snack trays printed in PLA are doing fine with a few pounds each.

Excluding quite extreme differences, different trays with the same wall thickness, and internal length/width dimensions will stack with each other, with most possible heights. Because the lean value does not depend on the dimensions of the box, you can print a 20 by 20 box of each height, with all the other settings you want, as a cheap way to do test fits. Increasing extra_space_for_easy_stacking and both wall thicknesses by a bit will help if anything is too constricted when stacking different height trays.

If you need any specific help, feel free to message me.