I live in a part of the world where air conditioning isn't really necessary, and during the brief part of the year where it gets uncomfortably warm inside, we usually just put a fan in the window. From time to time, though, I'd come home to discover that a surprise gust of wind had blown the fan onto my bedroom floor or sucked it out onto the roof. Luckily this is a problem easily solved with just a little 3D printing.

Here you'll find a clip you can print one or two of (I'm using two) for holding your fan upright under your window. You may need to make minor modifications if your box fan or window have a different thickness (this assumes 104mm and 36mm, respectively).

Changelog

• 8 May 2018: Updated design to be slightly thicker and use a fillet between interior window pillar and main body (v5). The original STL without those changes is still included as the v3 design.
• 11 May 2019: Updated design to be even bigger than the original by expanding the width of each clip, and adding fillets on all exterior sides. The original STLs are still fine, though! This will just be slightly less likely to become broken by having become crushed in your junk drawer over the winter.