This model is hard to print - read the hints or live with some wasted plastic!

What is This?

This is a model for really minimal Gridfinity 6U bins. They are basically just a single layer shell with a 0.5mm bottom plate.

There are two reasons why I created this:

1. I really want to waste as little filament on bins as I can. Environment and such, you know?
2. I wanted bins that match my calibration cubes that can be used as bins without the need to print them in vase mode. Vase mode is not a good thing if you want to fill your build plate with separate objects, obviously.

Printing Hints

This model is a bit of a torture test for your printer, even if it's well dialed-in and your filament settings are really good for regular prints. Have a look at my test object progression:

The one on the left was printed with my MK4 and Prusament PETG Anthracite Grey with stock settings in PrusaSlicer 2.7.1. As you can see, the seam becomes a problem if your shell consists of just one single perimeter. To be honest, the result was still way better than I had expected - respect to the Prusa engineers.

The one in the middle was created by setting the seam mode to “random”. It has holes like a piece of swiss cheese, but it's functional for holding nuts and bolts and to be honest: The hole pattern is quite pretty. Still, I wanted to get rid of the holes.

The one on the right uses the random seam and filament retraction was reduced to 0.2mm - it actually holds water and is just as sturdy as my vase-mode version, as far as I can tell.

All these prints were made on an Original Prusa MK4 with firmware 5.0.0, a 0.4mm Obxidian nozzle and a layer height of 0.15mm. Input shaping was active. Your results may vary if anything in your setup deviates, but the mitigations above should be a good starting point for getting something useful on your printer.

Whatever you try, though, you should absolutely make sure that your extrusion multiplier is set properly because this model will fail in spectacular ways if it is not. Sadly, I didn't take a photograph of it, but I had one experiment that could be seen as a piece of art, even though it didn't really resemble a Gridfinity bin.

Somewhat Parametric

In the FreeCAD file, you will find a spreadsheet with the parameters for this model:

If you want to create other bin heights, just alter the total height - 1U is 7mm and 2U (14mm) is the smallest sensible value. Then add 4.4mm to account for the stacking lip. So, if you need a 4U bin, just use 4*7+4.4 = 32.4mm as the total height.

The wall thickness depends on your print settings and it should typically be equal to your extrusion width. I assume that setting it to twices that value will result in a more sturdy double shell, but I haven't tested if that works. Please post a make with a comment if you try this so that others may benefit from your learnings. :)

The bottom thickness should be equal to the total height of your first 3 layers. As PrusaSlicer defaults to 0.2mm for the first layer and 0.15 for all subsequent layers, you end up with the 0.5mm in my default values. Feel free to toy around with this if you like thick bottoms.

Additional Credits

When creating this, the discussions with users of the Unofficial German Prusa Discord helped a lot - especially herbert, klausn and Daniel.B helped a lot. If you speak German, you should really have a look at this very civil and helpful Discord server.

Changelog