May 15, 2025
Description
I recently moved into a new apartment and, unfortunately, the landlord didn’t provide me with a key for the water valves. I borrowed one from a neighbor and, after measuring it with a caliper (triangle 11mm), I started searching for a suitable key.
After browsing dozens of listings from Polish stores, AliExpress, and Temu, I couldn’t find the right one anywhere. I even started studying the standardization of these keys, but it turned out there basically isn’t any...
So, I decided to design one myself.
The triangular and square keys are slightly oversized — by about 0.1mm (at the narrowest point, due to rounding) up to 0.3mm — to compensate for any possible printer inaccuracies while still ensuring the key won’t slip. Additionally, the model includes two extra keys: Circural 2-pin and Stepped square — their dimensions are shown in one of the photos.
I aimed to keep the overall diameter of the keys as small as possible (a smaller key will fit a larger hole, but not vice versa), while also making sure there’s enough room for at least two extrusion lines for a 0.4mm nozzle to prevent the keys from breaking easily.
Please note that some manufacturers create very non-standard locks — for example, an 8.4mm square — to maintain a monopoly on their keys.
Therefore, please carefully measure your lock, as it’s possible that none of the included keys will fit perfectly.
I’m also providing a .blend file with a key template and a centered origin point.
You can simply add a cube or a cylinder (3 armed) to customize your own key.
Printed with a 0.4mm nozzle, 0.12mm layer height.
Larger nozzles are not recommended.
Supports are generally unnecessary — my old Ender 3 only struggled a bit with the Circular 2-pin key.
License:
Creative Commons — Attribution — Noncommercial
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