December 30, 2022
Description
This originated as an idea for briefly pacifying children stuck at home during the COVID-19 pandemic. One child had recently figured out the concept of an Advent Calendar well enough to enjoy them, but was asking to do one long after Christmas had passed. So, we set to work thinking up what small item could be printed at home to place in a newly-renamed "Quarantine Calendar" for a few minutes of peace and quiet per day. A multi-purpose coin/token was our answer. Quiet Coins are easy to print (~10min, no supports or brim required), small enough to fit in at least our re-usable Advent calendar, and multi-functional: they can become many things based on what design you add to them. They can be the day's art project - whether blank or with an added design, have the kids paint them! Additionally, they are sized to match common checkers pieces, so they can be used as new checkers or as replacements in games: they're drop-in replacements for at least the edition of Connect Four that we have.
Usage ideas:
This is first and foremost a concept and starting point - you know your kids best and what they'd respond to. The coins have space to add a design (simple or sophisticated) either raised or engraved, and still be able to stack neatly. OpenSCAD sources, well documented, are included: to make your own decorated version, just include <token.scad>; and combine your design with baseToken();. The base design has been adjusted so that the top surface of the coin is at z=0, so you can add above or subtract below to your heart's content.
We'll add more designs soon, but we've started with the blank coin as well as a set of number coins: the digits 1-9, with little bumps/pips corresponding to each number, turning them into math manipulatives. I was able to print all 9 on a single run in a bit over an hour.
Most of the pictures show prints made with a 0.4mm nozzle (most common size), 0.28mm layer height, 2 perimeters and top/bottom layers, 18% infill, no supports, brims, or rafts, in eSun PLA-PRO. (Each coin takes about 10 minutes to print on my machine with these settings.) The model is very forgiving so just about any print settings that can produce something will work.
Details:
This is a very easy print. I tested with a 0.4mm nozzle, but nothing is that thin for the nozzle size to be critical. There's very little perceptible difference in quality between 0.2mm layers and 0.28mm layers, so feel free to use thick layers to save time if your printer is set up for it. I used eSun PLA-PRO in Cool White for the printed samples in the photos, in an old modified Makerbot Replicator 2X, but pretty much any filament printer should work. (SLA should also work, I would expect, if you can find isopropyl alcohol to post-process with - but that level of detail and precision is overkill.)
No bridging is involved, and the first layer is large and round so bed adhesion should be not a problem. Overhangs are limited to a 30 degree slope to make the lip for nested stacking, which should be doable even in a poorly-tuned printer. Infill percentage is up to you: I used 18% gyroid infill because that's what my default PrusaSlicer settings were, but it wouldn't necessarily need to be that high. You can go down to 2 perimeters and 2 top/bottom layers to further save print time.
The G-Code is for a Makerbot Replicator 2X with PLA in the left extruder. (I have a part cooling fan added too, but that shouldn't be too critical with this model.) I uploaded it just to quiet the warning - everyone with something other than a Rep2X (or FlashForge Creator Pro) will want to re-slice it.
License:
Creative Commons — Attribution
Rylie Pavlik
