BBQ 97mm to 40mm Blower Server Fan Duct press fit 1012 KH302

thingiverse

I designed this blower duct specifically for attachment to a Delta KH302 BFB1012EH blower fan, intended for use in stoking a fire pit that features a 50mm pipe with air holes drilled through it to enable airflow from outside into the middle of the fire. The outer circumference of the top circle measures 40mm, while the distance between the two flat sides is approximately 33mm. It fits onto the fan's output via press fit. The walls of this duct are about 2mm thick, although they do thin out in a couple of areas where the fan presses in. I printed it using my Haribo Prusa i3 mk2 at a speed of 60mm/s with 0.2mm layers, employing ABS material at a temperature of 245°C and a 40% fan setting within an enclosure that reaches around 50°C. Supports are necessary for the lip where the fan pushes in until it reaches its full insertion point. This lip is roughly equivalent to the thickness of the fan's case, providing a smooth airflow path. While I have yet to test this duct on the fire pit, my intention is to use a 12v 3amp fan to move a significant volume of air through the plastic, thereby keeping it cool enough not to melt.