MK2.5s - MK3s fan shroud modification...

thingiverse

3-19-2020 NEW Version uploaded V2 is a significantly improved version with greatly enhanced air flow. This remix of the fan shroud from Github has proven to be a game-changer for printer owners who experience thermal runaways due to excessive hot end temperatures. The standard fan shroud that comes with the printer and update kits allows far too much air to hit the hot end, often causing catastrophic overheating. To mitigate this issue, I initially reduced the fan speed to a crawl, but there's only so low you can go before it becomes ineffective. Undeterred, I located the Github model and made some crucial tweaks to the central air flow. The result is a design that still allows air through the part, but significantly reduces the amount of airflow directly at the hot end. By combining this improved fan shroud with a silicone sock, I've been able to safely operate my printer at 60% fan speed without any thermal runaway issues – a clear success in my book. Important note: To get the best results, it's essential to print this fan shroud in ABS as recommended by Prusa. With the silicone sock now part of my arsenal, I'm eager to test its limits with PETG. So far, the results are promising, but I'll continue to monitor its performance and provide updates accordingly. Update: Even with the sock in place, PETG was still running hot. In response, I printed a new version of the fan shroud in ABS and attached some photos for your reference. The good news is that it's still working flawlessly, and I've been able to crank up the fan speed to 80% without any thermal runaway issues – a major win.