Air conditionner centrifugal impeller

thingiverse

This is a printable impeller designed specifically for portable air conditioner condensers like the Supra Blizair Twin 4150R, but can also be used with other models that utilize the same 21x11 impeller. I created this impeller as a replacement after the original part self-destructed due to wear and tear. I divided the print into multiple parts to minimize material waste in case of failure, reduce excess support material, and optimize print orientation for maximum strength. The STL file fan.stl accurately describes the original fan design, while modified_fan.stl showcases an assembled view of what I printed. The other STL files represent individual parts, carefully oriented for optimal printing. After extracting the aluminum shaft from the broken part using acetone, I inserted it into place after heating it in the oven to make it fit perfectly. Initially, I designed a version in ABS plastic, which functioned well for a few minutes before overheating caused it to deform slightly. The centrifugal force then amplified this deformation, causing the impeller to hit the housing. Based on my experience, I believe that printed ABS parts have too much tension due to layer shrinkage, making them less heat-resistant than injected parts. To overcome this issue, I designed a second version in polycarbonate and increased the thickness of the bottom around the blades for added rigidity. This impeller has performed flawlessly, withstanding continuous use over several days without any issues.