Redesigned Qidi Q2 Toolhead Model Cooling Fan Duct with Air Intake Fence

Description

The stock model cooling fan duct sucks. Here I have redesigned one. The main purpose is to add air flow guiders so the cooling air could be more even and stronger. To maintain the dimension is important so it would not cause other problems such as bumping somewhere etc, and it should be easy to print and to assemble as well. I also think that it would be nice if I can keep its original looking. 

The new design comes with four main parts: 

• Main Body, same shape, same looking, same dimension.

• Air Duct Cover, to cover the air flow guiders. It also has magnet slots for placing the original front cover.

• Bottom Cover, for original big mouth (38mm) fan. Added thin walls to guide the air flow.

• Top Mounting Cover, to connect all together and mount on the toolhead's plate.

One of my ideas is that, if you are an experienced hand craft guy, you could even use the original duct part to cut it to adapt the other two parts without printing the Main Body and Top Mounting Cover from this design. Then you will have the exactly same exterior looking, nobody knows you have ever changed it. lol~

A new optional part (Air Intake Fence) was uploaded on Jan 11th, 2025. See the Updates below for the details.

I have uploaded six files, two 3MF files and four STL files. The reason is that the Main Body and Air Duct Cover need support to print properly. So I designed the printing support (designed for 0.2mm layer hight) particularly for these two parts and saved in 3MF format, and saved the STL files without support. You could either simply print the STL models (4 of them) or pick the Main Body and Air Duct Cover in 3MF to print, the Bottom Cover and Top Mounting Cover in STL.  There are newly added 3 files, please refer to the  Updates below for the details.

Highlights

Instead of the empty duct chamber, one of the main features of this design is to add carefully arranged thin walls (Fins) to conduct the air flow more evenly distributed. 

Also, it may not be easily discovered, I have opened up both sides of the front to allow the air go through the front, which originally were blocked by the posts for magnet installation. This gives much better cooling effect by providing 360° degree air flow as the stock duct only can provide less than 270° degree uneven air flow. The uneven and uncontrolled air flow may cause other problems such as blow the freshly extruded filament askew from the right position.  

About The Fan

This redesigned cooling duct 100% fits original fan, not other changes are needed. It can improve about 2 times better cooling effect according to adopted users' feedback . 

Other than the original (5015) big mouth (38mm) fan (around 7000rpm), there is another fan has the same dimension but more powerful (around 9000rpm), which is the fan for BambuLab X1. It's easy to find out from the market and 100% compatible. However, you'll need an adapt cable (MX1.25 female to PH2.0 male, as you can see in my pictures) in order to use it. You also need to switch the two power wires. That's it. 

There is a newly added experimental Bottom Cover design for small mouth 5015 fan, 19.5mm wide mouth, which allows to use more common fan type. And Qidi Q2 does have some machines were assembled with this type of narrow mouth fan, probably on older batch of products. Huge thanks to @OfflineREX_3965786  for his professional contribution! 

Printing Tips

• Globally, setup the Line Width to 0.4mm, at least 3-wall, 3-top layer, 3-bottom layer, mine are all 5.

• The default layer hight is 0.2mm. As to the 3MF files, slice the support (in Objects) seperately with 1-wall, 0-top shell layer, 2-bottom shell layer, 20% Grid infill. Note, the 3MF files don't come with slicer parameters, you'll need to deal with it in your own slicer, such as the Lay on Face, etc.

• You can use the STL files if you want to print in different layer hight or setup your own support. 

• Use heat resistant material to print of course. :-)

Updates

Jan 8th, 2026

Uploaded a modified version of the Air Duct Cover, changed the hole shape to flower type so it should be easier to snap the magnet in and easier to apply glue in it.

And I uploaded a .step file of the Air Duct Cover (pre-supported) as well, for ones who wanted to make some modification.

Jan 11th, 2026

Uploaded a new designed model Air Intake Fence, to prevent the wires in the toolhead's back drop into the fan intake which could cause serious problem. It could also be installed on the stock cooling fan duct since the dimension is exactly the same. It added 0.8mm hight on top of the installation screw holes, the original screw should fit.

Feb 4th, 2026

Uploaded an experimental Bottom Cover model for small mouth 5015 fan, 19.5mm wide mouth, in step format. Huge thanks to @OfflineREX_3965786  for his professional contribution! For ones who are interested about the design, you can dig out the discussion between me and @OfflineREX_3965786 in the comments section. :)

BOM

Well you do need some screws to put them together.

Notice: 

Because of the Air Duct Cover has two ears to mount on the original holes. And that two ears have added 2mm thickness. Hence at least one of the original M2.5x5 Hex Socket Cap Head Screws needs to be replaced with a M2.5x8 counter-sunk screw to avoid interfaring with the hotend cooling fan on the right side. 

Installation Diagram

Installation process

Two M2x8 Counter-Sunk Slf-Tapping Screws are mounted at the back and side.

As shown on the above diagram, because of the Air Duct Cover has two ears to mount on the original holes. And that two ears have added 2mm thickness. Hence at least one of the original M2.5x5 Hex Socket Cap Head Screws needs to be replaced with a M2.5x8 counter-sunk screw to avoid interfaring with the hotend cooling fan on the right side. 

Newly added Air Intake Fence

How to Place Models in Slicer

Placing the Bottom Cover and Top Mounting Cover

Placing the Main Body and Air Duct Cover with support.

Placing the Main Body and Air Duct Cover without support.

Enjoy！