Print Details

This model was inspired by Kingy23's Coffee bean dosing tray (V2 update). But I lost the STL that they made, so I decided to model a new one while fixing some problems I had with it. Using the Loveramics/TensHundredsThousands Dosing Tray as inspiration for the shape and features.

Two models are provided, Small and Large. The smaller one is the original design, and the larger has been scaled up 125%.  The former works best for 1-2 cup brews, while the latter works better for batch brews.

Dimensions

*The larger number is to show the capacity when filled to the brim. But the lower number is closer to the capacity that one would use for RDT. Please note; due to the varying weight, size, and roast level between beans  specific numbers can't be provided.

Printing Tips:

I designed only 45 angle overhangs, so this should print easily. But I would recommend the following to help ensure that it prints smoothly

• Lower print temperature to help the layers cool quickly
• Ensure the fan is on full blast when printing overhangs
• Slow the print down when printing overhangs.
• Make sure the spout (the part with the most overhangs) is facing towards the fans on the extruder.

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Please Note: 3D Prints are not food safe!

I recommend you only use this print to measure dry whole coffee beans. As you cannot be sure that your filament will not leach out unsafe compounds, prevent microbial growth when exposed to water or other liquids, or prevent microbial growth when ingredients and items get caught in crevices or layer lines. For this reason I suggest that you avoid doing the following;

• Using the Ross Droplet Technique
• Measuring ground coffee
• Measuring tea
• Measuring liquids, and fine dry ingredients meant for consumption

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Motivation

I tried other models for dosing coffee beans and experimenting with the Ross Droplet Technique (RDT). However most models I found tended to either be aesthetically ugly, shallow, the beans bounce out too easily, and/or have too narrow of a spout to work properly. The most successful one I saw was the aforementioned one by Kingy23, however it was still pretty easy to make beans bounce out; and the spout was too shallow which made beans often flow away from my grinder or centrifuge tubes (which I use to freeze batches of beans, and take with me when travelling).

I took inspiration from the look and proportions of the Loveramics/TensHundredsThousands Coffee Dosing tray. Which in turn was inspired by Cha He tea vessels, used to measure and display tea in Chinese tea ceremonies. Like the inspiration, this model features a deep but narrow mouth for easy pouring into small openings, gentle overhangs over the bowl to prevent beans from bouncing out, and aesthetically pleasing proportions to make this model wonderful to look at and pleasing to handle.

Unlike it's inspiration, this model features more gentle overhangs to prevent issues while printing. And it features a gentle teardrop shape, unlike the Loveramic's mostly circular proportions; to help make it easier to handle and take less space in a travel coffee setup. Additionally, I gave it a slightly narrower opening to make it easier to pour beans into 50ml centrifuge test tubes.

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My Settings

The print in the picture was printed with a Prusa MK4 with Input Shaper enabled and a 0.4mm nozzle, using the 0.15mm STRUCTURAL &MK4IS 0.4 preset. Additional settings I used to help improve the quality of the print;

• Layers and Perimeters
  • Perimeters: 5
  • Avoid crossing curled overhangs: Enabled
  • Scarf joint placement: Everywhere
• Infill
  • Top and Bottom Fill Pattern: Concentric
  • Fill Pattern: Rectilinear
  • Fill Density: 100%
  • Infill before perimeters: Enabled
• Speed
  • Dynamic overhangs speed: Enabled
  • speed for 0% overlap: 10%
  • speed for 25% overlap: 20%
  • speed for 50% overlap: 33%
  • speed for 75% overlap: 50%
• Support Material
  • Generate support material: Disabled

For the filament, I used Polymaker Polyterra Charcoal Black. And I would recommend the following settings in PrusaSlicer with this filament:

• Nozzle First Layer Temperature: 205C
• Nozzle Other Layers Temperature: 195C
• Max Volumetric Speed: 12mm³/s