Fully parametric upcycling modular drawer lockable cabinet generator (25 grams/drawer)

Put your old physical media racks to use again!

This fully parametric drawer generator will generate drawers with user specified dimensions and compartments. It has been programmed to maximize strength while minimizing material and printing time.

A CD case sized drawer weighs 25 grams and prints in 1 hour, but with a 0.6mm nozzle only 30 minutes. Bigger drawers are still easily kept below 100 grams and 2 hour printing time. A DVD case drawer weighs 29 grams. I recommend swapping to a 0.6mm or 0.8mm nozzle if you are going to print many of these, because not only do big nozzles significantly cut your printing time, they also reduce the amount of seams in the print, increasing strength and allowing thinner walls.

I tried to add features and print optimizations, while keeping everything as flexible as possible. I designed six different handle styles, as well as optional label space which can be assigned separately on both sides. Preset sizes are CD, DVD, VHS and audio cassette cases, but if you can think of other useful formats, please let me know and I can include them.

Post contest edit:

Honoring Prusa fashion, added an extra feature to the generator to include locking of the drawers to avoid them falling out during transport :-)

The drawer generator

Drawers are generated according to user specified parameters, all parameters are at the top of the file. The generator modules are written underneath and the modules are then called at the bottom of the file. If you open the file, you can press F5 to generate a preview.

Drawer parameters include:

• Size (Width, Depth, Height)

• Number of rows and columns inside the drawer

• Horizontal wall thickness

• Vertical wall/floor thickness

• Chamfers for added strength, adjustable in height

• Diagonal raised cross to increase strength and allow reducing floor thickness further

• Separate slot-to-slot height and rails width for multiple slot height drawers, second width for cabinets that are narrower in the back

• Bridging height, so you can keep vertical walls small while ensuring enough layers in the handles to make them look neat

• Optional mini brims on the corners so they won't come off the printbed, but without the material and time cost of a regular brim (they are 6mm in diameter and have a 0.2mm separation gap)

The chamfers increase strength significantly, for most purposes you can get away with 1mm walls and below 1mm floors if you include a chamfer of 1 or more millimeters.

You can choose the style of the handle too, and fully parametric as well:

The handlestyle 2 also has a slight inwards profile so the bridging distance at the top is slightly smaller.

Cabinet generator

A fully parametric cabinet generator is also included, dimensions are calculated automatically from the drawer dimensions in the script and the amount of drawers you want. Keeping material costs low is tricky for something so large, although I still was able to keep an 8 slot DVD case cabinet under 350 grams. Cabinets can have interlocking forks on all sides, the vertical ones stick out and the horizontal ones are integrated into the walls. 

Parameters:

• Drawer used and amount of drawers it should fit

• Wall thickness, used for all five sides

• Back wall can be solid, or only a diagonal cross with horizontal bar of variable width

• Rails for the drawers have adjustable width and thickness

• Extra space can be added between the rails to make the drawers fit easier to slide

• All cabinet dimensions are calculated based on the drawer dimensions and parameters above

• Drill holes can be generated (variable diameter and a second diameter+sinkheight for flush bolts)

• Interlocking clamps can be generated on all four sides;

• Clamps have variable width, height and length

• Bottom interlock can be used as a foot too, simply set the height a bit higher

• Vertical interlocks stick out and give a segmented look, while the horizontal interlocks are hidden inside the walls to give a uniform look

• Bottom and right interlocks are covered from the top for fixed links hide the interlock mechanism

• These interlock tops are long bridge overhangs, you can either print them as is, or use one of two options to improve them:

  • Interlock bridge intervals can be added, which are small 45 degree ribs that are printed right before the cover itself, cutting the bridge length by 4

  • Drop in bridges, these are small slates that have to be printed first, and then placed in the opening when the bridge time is reached, using the pause command in the slicer.

• Additionally, the placement for these interlocks is in the center, but you can also set them to a set distance to align differently sized cabinets along the wall (to fill a corner of your workbench neatly)

• A locking feature is added, an optional sleeve can be generated at the front of the cabinet so you can insert either an L-shaped bar or use straps to prevent the drawers from sliding out during transport.

Having the interlocking features parametric also allows for connecting different sizes of cabinets to each other, as you can give them the same size. Be sure to keep the length of the interlocks long enough (the distance they run from the back to the front of the cabinet), if these are too short, the cabinets can fall over forwards.

I also created an extra module that generates 4 interlocking cabinets with one big drawer each, that fit in the same footprint of a cabinet with standard drawers. The top two have a standard interlock together, so you can link them underneath your other cabinet.

How to use drop-in bridges

You can get perfect bridges by printing them beforehand in form of a simple bar. Leave out the bar at the bottom of you overhang with a small tolerance (like 0.5mm) and make sure it makes a clear slot that the bar can fit in. Print the included bridge pieces first (wait a bit for them to cool and avoid them from being warped), and add pauses at the layer where the bridges are being printed (blue in the images below). Go to this exact layer where the bridge is made, and add a pause. After inserting the bridge, the printhead will have a solid underground to lay the first layer on.

About the software and this project

This has been written using OpenSCAD, a free and open-source coding based CAD tool. Everything is built up from cubes, cylinders and spheres that are placed using code. If you've never heard of it, download it and give it a go, it's tiny and runs on anything locally. All the parameters are at the top of the script, and scroll down to see the drawer calls (you can comment them out to hide them by adding // to the front, or removing the // to see it).

OpenSCAD is a bit tedious to get used to, but for parametric designs that involve determining dimensions using formulas it can be very useful. The Prusa MK1, 2 and 3 were designed using this too!

Inspired by one of Chris Borge's models, but tried to take it to the next level.