4 Inch Duct Adapter for Creality K1

This adapter allows for 4 inch dryer duct to attach to the exhaust of the K1's chamber fan. 

No supports required.

The only hardware required:

• 4 bolts that are a at least 25mm long (ideal) or longer (30mm will also work).
• 4 washers if using the M2 and M2.5 bolts.
• 4 matching hex nuts. 
• Dryer hose
• Dryer Clamp

There are different versions with different lengths of duct-transition and different bolt options.

The original (and longer) versions meet the commonly used 15° maximum angle for duct transitions. The short versions are simply shorter but do not meet that rule. How much you care about maximum transition angle likely depends on if you have a strong in-line duct fan or not. If you do not, I recommend the original version for maximum air flow. 

The M2 bolts will work without modification to the printer but you will need washers for the fan side. Simply remove the existing bolts for the chamber fan and replace with the new bolts. 

The M2.5 bolts may work without modification (not tested) but the hole will definitely be tight. You will also need a washer for the fan side.

The M3 bolts will require the existing screw holes to drilled to slightly larger than 3mm. The holes are not far from 3mm so this a very minor change. However, the original screws will no longer work. I only include this an option in-case the M2 and M2.5 bolts are hard to get.

The nuts simply need to press fit into place. I used a set of channel lock (my favorite tool) and it was very easy (and satisfying) to press them into place. 

I used 3 wall, top, and bottom layers with 15% grid infill for the print. Its very strong.

Enjoy.