Built upon the Gridfinity Storage Box by Pred, this multi-box storage system allows effortless access to multiple storage boxes while maintaining their stackability. Additionally, the modular handle provides optional portability.

The solution also includes optional mounting capabilities for wall installation using a French cleat, although this feature has not yet been tested.

Technically, this storage system can be used with just about any kind of storage box due to the parametric design.

The storage system is assembled using M3 button head screws and bolts. Most makers are likely to have M3 assortments readily available; however, for those who don't, the following kit was used during the construction: https://a.co/d/0gfEO0l. This kit has ample screws for a 4-tall storage unit with plenty to spare. However, if you build multiple units, you may run start to run out of M3x6mm or M3x10mm screws and may want to pick up those sizes individually.

What do I print?

A basic storage unit requires:

• A left side panel and a right side for each box being stored
• A back support plate for each box being stored, minus one. For example, if storing 4 boxes, you need 3 back support plates.
• A top plate. I recommend the solid top plate with handle holes.
• A bottom plate. I recommend the wireframe bottom plate.
• 2 feet (optional but recommended).

Standard printing configurations should be suitable for all parts. No supports are required for any of the components.

I printed all parts without a brim, but depending on your printer's reliability, you may find it beneficial to use a brim for added stability during printing.

Note that almost all parts are printed with their external surface facing down on the print bed, emphasizing the importance of bed adhesion for a smooth surface finish. This also allows for the use of a patterned print bed for unique surface effects.

Important - Multi-Level Side Panels

Multi-level side panels allow you to print multiple side panels as a single, unified piece, reducing the number of components and screws needed. This design enhances overall stability and strength while utilizing slightly less filament (approximately 5g per level). Whenever possible, opt for multi-level side panels for increased efficiency.

For general use, I suggest primarily printing the 2x side panels. I've included 3x and 4x options as alternatives, but they likely won't fit on most print beds.

Additional Options

Feet

While not technically required, feet are a valuable addition, especially when using the wireframe bottom. They cover the exposed hardware and help prevent scratching any surface the unit is placed on.

For a soft, malleable foot, you can print it in TPU with 10% gyroid infill. PLA and PETG are suitable alternatives if TPU isn't available or preferred.

Attach the feet to the bottom wireframe plate using M3x10mm screws and to the bottom solid plate using M3x15mm screws.

Handle

The handle is a great option for portability. To incorporate the handle, you will need to print:

• Top plate with handle holes
• Handle
• 2 left handle mount
• 2 right handle mount

The handle mounts are attached to the top plate using 8 M3x10mm screws. The handle itself requires 2 M3x30mm screws.

The handle has undergone extensive testing with 4 loaded storage boxes, demonstrating considerable strength. However, I advise against using the handle with more than 4 boxes, considering that storage boxes can become quite heavy when fully loaded.

French Cleat

The option to mount the storage unit to the wall using a French cleat is available. However, as I haven't personally tested this feature, your input would be valuable. Please use caution when loading the French cleat mount with weight. While it should be quite strong, I haven't had an opportunity to fully test its strength.

The French cleat mount is based on ¾" plywood (21/32", ~16.67mm). Please let me know if other sizes are required.

Boxes full of hardware can get really heavy. You may want to consider using two French cleats. Alternatively, you can use the French cleat spacer to support the bottom against the wall, distribute the weight more evenly and reducing the strain on the mounting points.

To utilize the French cleat, print the French cleat mount and attach it to the back. The French cleat mount is used in conjunction with the back support plates and is positioned behind them, without replacing them. Use M3x12mm screws in place of the M3x6mm screws typically used to secure the back support plates. You can use M4 flat-head screws to secure the unit to the cleat, if desired.

The French cleat spacer is installed in exactly the same manner.

Tip Prevention

The back support plate offers the option of including tip prevention screw holes, which can be added based on user preference. These holes are not intended for wall mounting, as the back support plate is not designed for such a purpose due to its limited strength. Instead, they are intended to secure the unit to the wall and should only be used when the unit is placed on a stable surface. They functions similarly to the tip prevention mechanism commonly found in dressers.

Top Wireframe Plate

The wireframe top plate allows for approximately 25% less material usage. However, it does not support the use of a handle.

Please refrain from using the plastic cross beams as a handle as they are not intended for this purpose.

Solid Bottom Plate

An optional solid bottom plate is available, although it's generally not required in most scenarios. Since the bottom isn't typically visible, the wireframe bottom plate should suffice for most purposes. However, if you prefer its aesthetic or need additional strength, the solid bottom is a viable option.

The solid bottom is attached with M3x10mm screws if feet aren't included, or M3x15mm screws if feet are included. Please note that the solid bottom uses approximately 2.5 times as much material as the wireframe bottom.

Middle Plate

The middle plate is largely unnecessary. It isn't prominently visible when the storage unit is fully loaded. While it does offer added rigidity, it requires a significant amount of extra material and should not be necessary for most use cases. It is available for those who may find it useful, but it's not a strongly recommended component.

An alternative wireframe option is also available, conserving approximately 25% of the material used.

The middle plate is printed in two parts, the middle plate itself and the middle plate back support. The middle plate is mounted between two layers using M3x12mm screws, while the middle back plate is attached with M3x6mm screws.

Assembly

To begin assembly, start from the bottom and work your way up. Mount the left and right side panels to the bottom plate and optional feet using the appropriate-sized screws. Then, stack the side panels together using M3x6mm screws, ensuring proper orientation. Attach a back support plate between each level using M3x6mm screws. If you're using the French cleat mount, install it while fitting the back support plates.

Installing the handle before attaching the top plate can simplify the process. Finally, secure the top plate using M3x10mm screws on the top and M3x6mm screws on the back.

I found that installing the screws using just the bit, without the handle, worked well. The nut does most of the work, allowing you to tighten the screws sufficiently even without the extra leverage from the handle. This method can be particularly helpful for installing screws at awkward angles.

Consider using a threadlocker on the screws, if available, for added security during assembly.

Customizing with Parametric Design

This model was created in FreeCAD using parametric design. This is done using the object ‘Parameters’ within the FreeCAD file. To adjust the Gridfinity configuration, change the parameters in the ‘Gridfinity’ section. For non-Gridfinity boxes, you can modify the box dimensions directly in the 'Box' section. You will first need to remove the formulas by pressing the = (equals) key and then pressing clear.

If you need to modify the hardware dimensions, navigate to the 'Hardware' section. Keep in mind that a screw and nut depth greater than 2.5mm may not work well with the default 4mm floor thickness, which can be changed in the 'Secondary Parameters' section. I recommend avoiding changes to most of the other secondary parameters as they may have narrow operational limits and altering them could potentially break the model. It's best to refrain from modifying anything in the 'zCalculated' section as these calculations are essential for the model's support and altering them could lead to unintended consequences.

Once you've determined the appropriate parameters, open the "Print Ready" folder, which contains the models pre-rotated for optimal print orientation. To export each part, click on the desired component, and select File > Export.

Fostering Community and Modular Innovation

The beauty of a modular design lies in its versatility, enabling individuals to create customized modules to suit their unique requirements.

I've incorporated a range of modular options, but there's always room for more innovative ideas within our community. Let's collaborate and discover the endless potential of our collective creativity!