Smartitions: Create Lasercut Custom Partitions for Shipping!

Let's say you want to ship a PC or a Mason jar or a 3D printed part, and being the normal human being you are, don't have large volume of packing peanuts. If you can model the object, you can make a custom cardboard lattice to protect it!

Where I work, we accumulate incredible amounts of cardboard every week. While we do have recycling, it seems terribly wasteful throwing out flattened cardboard boxes without reusing it at least once. My department, despite having a lot of powerful and shiny equipment for making things, has a laser cutter. It is by far my favorite tool to use. I started with 2D engravings, then moved to 3D boxes and enclosures using all manner of joints. Then I discovered Autodesk 123D Make. Like most folks who have downloaded it, I had a lot of fun designing stack-able objects from cut sheets I had around: soccer balls, a model of DNA, the school mascot, etc. While using all of this scrap cardboard, it really got me wondering... What about non-objects? You know, holes, gaps, voids, hollows, cavities. I could create custom cardboard lattices for shipping delicate items while reusing scrap cardboard!

This Instructable will show how you can use free tools like TinkerCAD and 123D Make to create your own custom cardboard partitions / support ribs for cardboard box interiors. Makers rejoice! You can ship like the pros do!

For this you will need.

1) Your object to be shipped.

2) A box to hold your object comfortably.

3) Some cardboard sheet, preferably all the same thickness.

4) Computer with 123D Make and a browser for TinkerCAD or 123D Design. You can use nearly any CAD software you want, and since 123D Design is still new, these steps are for TinkerCAD.

5) Laser cutter.

Your Object
If you already have an STL file of your object from your own design or from a 3D scan, feel free to skip to the next section below.

For my side business, I need to ship Mason jars. While the shape of a Mason jar is admittedly simple, you can follow these steps with nearly any object. I wanted to keep the procedure as straightforward as possible. I find that starting off with an oversized workplane in your favorite units with the largest step size is best. When you need more finesse for maneuvering your objects you can shrink the size and return to a larger step at anytime.

For nearly all objects you will be modelling only the exterior. I will be using two cylinders (lid and container volume) and two hemispheres (the top and bottom tapers). I could play fast and loose and just use a single cylinder. But, the more detail you put into your model, the better your result. My model is about 7 inches tall and 4 inches across at its widest. Once you're finished, group all the sketch's components together and admire your creation.

Your Box
With your model complete, it's time for the magic. The box I will be using is a 9-inch cube. Grab the Box shape and drag it to the workplane. Resize it to the dimensions of the INTERIOR of your shipping box. Once you're happy with it, select both your object and the box and click the Hole option on the right of the screen. This is TinkerCAD's subtraction tool. Place your object inside the box, noting that you will likely need to raise it up so it occupies the center of the box volume. If you don't there won't be any support ribbing later on. Now, select your box volume and click Color on the right side of the screen. This returns volume to the box shape and box shape only. What you can't see is that inside is a now a void the same shape of your object!

To save your model, select "Download for 3D Printing" form the Design dropdown. Save as an STL file.

Importing

Open up 123D Make and use "Import..." to select your STL file. You'll be presented with a your box in a grey workspace. At this point, check to ensure your dimensions match with reality. I've found that importing can scale down sizes. If this happens, fret not. Simply adjust with the panel on the left.

Interlocked Slicing

For this part of the process, I can't hold your hand very much. Your object will be different from mine. I will show you how I went about with the Mason jar and you'll just have to experiment for your preferred results. Make mistakes, and have fun!

For what we wish to accomplish with making our lattices, there are two viable options under the Construction pane: Interlocked Slices and Radial. I began preparing for this Instructable using Interlocked Slices. This tool takes your STL 3D object and slices it into planes along two perpendicular axes. The number of planes can be adjusted and for sanity's sake, reduce it to 3 or 4 per axis for now. You'll quickly see how the partitions will work. They occupy a (usually) cubic volume but there is a clear void within it where your object will sit safely. You may have to reorient the Slice Direction to get the planes to intersect the void just right. Use Assembly Steps to see an animation of how your cut cardboard will look. This is where you may notice something odd happen, or not!

Radial

123D Make doesn't know that a solid object will sit within the center void eventually. So it will attempt to construct the box planes in a way that would cut through! It's like a rookie magician actively sawing the volunteer in half on stage!

To my surprise, I've found that using the Radial setting to be best. Where the Interlocked Slices are rectilinear and uses a construction method that cuts across and through the box, the Radial style builds from the outside into the center. So, if you have an solid object in the middle, the incoming slices stop at or near the center. Your mileage may vary. In the case of this mason jar, it was not only easier to build with Radial, but saved a bit of cardboard. As you can see above, I chose 4 vertical planes and 3 radial planes. While I could have done 4 and 4, I really liked the asymmetry of 4 and 3.

Get Plans

When you've finished spinning axes and replaying the Assembly Steps, you're ready to laser cut. There's been a preview of what your cut sheets will look like the entire time you've been working in 123D Make. You can adjust the sheet size on the left and see the result on the right. There's a handy custom option when you're stuck with irregular sheets like I do. Click Get Plans at the bottom left panel and export your favorite file format.

Laser cutting

The vector files may need cleaning up to remove artifacts but at this point, it's smooth sailing. Standard laser safety applies: ventilate, never leave unattended, have a fire extinguisher nearby.

Assembly and Conclusion

Recycle the excess cuttings and assemble your partition lattice! I had a snug fit with my jar but its better than a loose one. After rigorous unscientific testing, I am very confident my little jar could withstand the worst that shipping couriers could dish out. I have video of dropping this box with an open lid from a height of 15 feet and both the box and the jar remained intact! As an added bonus, it's naturally compartmentalized for smaller items within the box. Shipping a laptop? The cords can stay sequestered in their own space. Selling a kit? You can laser etch what parts go in each section for easy packing and unboxing.

With free and easy access to CAD tools and the growing popularity of 3D scanners, I believe you can use this technique to ship nearly anything!

Thanks

I had a lot of fun creating this. I hope you enjoyed reading about it. I have to thank my wife, Stark, Sims and the Seniors.