Duplicator D9 fan duct II

prusaprinters

After switching to a bondtech extruder on my Duplicator D9 (400 MK2) I noticed an increase in heat-creep induced artifacts on my low-temp material prints. I was expecting this somehow since a few factors are handicapping proper hotend-cooling on this machine: all-metal hotend replacement of the aluminum extruder block by a plastic extruder block printer in enclosure So after I semi-failed on the part-cooling fan (https://www.thingiverse.com/thing:4044949), I decided to give up my previous approach in trying to use the given fan and started with shopping for the most ridiculously overpowered 24V radial fan I was able to get my hands on. Here's that beast: https://www.distrelec.at/de/radialluefter-dc-dc-51x15x51mm-24v-6m-rlf-35-ebmpapst-rlf35-14n/p/15421093 Finally I'm able to use my hotend as a hair dryer. But my actual goal was to never-again worry about heat-creep, and this one - although pretty pricey - does that job very well. A cheaper and more silent fan might be a better idea in most cases since this one draws more current than the printers mainboards can supply. A more sane fan-choice with a power rating that matches the original one will spare you tapping 24V directly from the PSU. Further downsides are an increased noise level (which isn't an issue since it's under a cover) and more weight (very close to the x-axis, so no big deal either). To prevent the duct from leaking and causing drafts over your print I recommend lining the x-carriage with some sponge rubber. And this is the only thing you need except from the fan and the duct. Oh: and some tape or foil to cover that big hole right underneath the original fan. You can see it in one of my pictures as some yellow foil. The fan is mounted by clipping it into the duct and the duct is held in place by 2 screws that are already installed on the stock hotend. Just use these and maybe some shims. That's it. Good luck. ~~Further plans: A slider to split the airflow and use it for extruder motor cooling or part cooling would be nice. And maybe make an adapter for the fan to suck air from outside the print chamber.~~ edit: all done. Except for the part cooling part. Outside-adapter soon to be uploaded. editedit: ...instead I made a shovel-like thing that forces the strong airflow from the heatsinks outlet upwards. Without that there's a chance of causing a draft on prints. editeditedit: So there's this comically overpowered fan on my printer, yet my extruder motor is getting too hot to touch under certain circumstances (enclosure closed, bed at 120°C, high volume flow); considering that the original fan also provided some tiny amount of cooling to the e-motor, I can imagine the lack of such to cause problems with future prints. Therefore I decide to pressure-relief my fan with some air channels that just pass the motor block. Additionally I tweaked some clearances to minimize escaping air even further. These make installation harder - it looks like the holes don't fit but that's intentional, so you have to use some pressure against the backplate for mounting. Print Settings Printer Brand: Wanhao Printer: Duplicator9 Rafts: No Supports: Yes Resolution: 0,15mm Infill: 0% Filament: ColorFabb HT clear Notes: The given orientation for the inlet is the one I can recommend printing. The shovel needs to be rotated by 90°. Also use some support. Material-wise I tried PETG for the early prototypes and they seemed to withstand testing on some small high-temp prints. For the final part I chose a CPE from [colorfabb](https://www.amazon.com/colorFabb-90-285-113-Filament-Diameter-Black/dp/B01I4VZXNK?dchild=1&keywords=colorFabb&qid=1618263217&sr=8-3&linkCode=ll1&tag=thingiverse09-20&linkId=1ee3dc99cc4c4e6ea97eb2d25ece1b71&language=en_US&ref_=as_li_ss_tl) that they call HT (basically tritan) and is supposed to withstand temps over 100°C. Category: 3D Printer Accessories