Duplicator D9 fan duct

thingiverse

Here's the result of countless iterations trying to improve the part-cooling fan included with the Wanhao Duplicator D9 (MKII 400). It's supposed to fit the original 4010 fan without requiring any disassembly, simply using 2x M2,5x15ish screws + nuts (optional) for attachment. At first, I wondered why Wanhao didn't put more effort into their part-cooling design. Now, I understand... the original duct-less design is sufficient for almost all needs. If you still want to try a fan-duct, you have three options (with names reflecting their appearance): * The Poo: This one features an organic shape and was designed in Blender. I'd like to use that as an excuse. Initially, it looked nice but needed constant improvements to enhance airflow, eventually resembling a piece of junk. However, it actually works, albeit not much better than without a duct. One issue with these 4010 fans is their uneven flow distribution; measuring air velocity on one of these fans revealed a ~75% drop-off from one side of the outlet to the other. Additionally, there's likely a swirl that I wasn't able to measure exactly. So, I started over completely, utilizing flow simulation and parametric CAD. Here are the results: * The Vortex: As its name suggests, this one creates a vortex with the "eye" at the nozzle. Unfortunately, it decreases air velocity more than duct-less designs, making it almost useless for part-cooling. However, it can prevent cooling your nozzle... which can also be achieved by not using a fan at all. * The Pincer: This crab-pincer shaped version is designed to have decent airflow just below the nozzle while not obstructing the view on the extrusion. It works somewhat but isn't overwhelmingly better than duct-less designs, making it fine. I half-recommend this one. Pictures differ slightly from the CAD file; these were older versions. By the way: The picture of failed designs shows only a fraction of the actual failures. Most went straight into the trash after trying. I know this is nothing to brag about, but I think some people might relate to that, which is why I uploaded it too. edit: Sorry for the wonky layout. It looks fine in the preview but Thingiverse decided to go nuts as soon as it's published. Also, the aspect-ratio of the pictures is supposed to be... normal. One last disclaimer: I made these ducts for my printer with almost every part modified. There's a chance they won't fit on your printer. Specifically, I'm worried about the BL-touch probe which has a slightly different position on my D9, and I'd appreciate feedback on that. Also, there's a chance for the duct to almost touch the print surface when you have a very short heatbreak. So, don't install your all-metal hotend on the topmost position.