This is a modular cooling system designed specifically for the FYSETC Catalyst‑K motherboard. The mount consists of two parts:

Main Fan Mount Body
Interchangeable Blower Ducts

3‑Driver Duct — cools Motor E1, Motor E0, and Motor X
5‑Driver Duct — cools all five drivers on the Catalyst‑K

Features

Modular duct system (swap between 3‑driver and 5‑driver versions)
Dedicated blower cooling for stepper drivers
4010 fan cooling for the MCU and board surface
Clean cable routing with underside hooks and zip tie positions
Uses Catalyst‑K’s FAN1 and COOL‑FAN headers

Fan Header Information (Important)

FAN1 (J25) — Blower Fan

Connector: JST‑XH 2‑pin (2.54 mm)
Voltage: Selectable via jumper (5 V / 12 V / 24 V)

COOL‑FAN (J29) — Motherboard Cooling Fan

Connector: JST‑PH 2‑pin (2.0 mm)
Voltage: Selectable via jumper (5 V / 12 V / 24 V)

Make sure to set the voltage selection jumpers on the Catalyst‑K board to match the fans you are using.

Klipper Configuration

(NOTE: I have yet to test this. Verify everything first with the Catalyst Wiki)

Blower Fan on FAN1 (J25)

Add this to your printer.cfg:

#############################################

[fan_generic driver_fan]
pin: PA3
max_power: 1.0
shutdown_speed: 0
kick_start_time: 0.5
cycle_time: 0.010

#############################################

This will show up in Mainsail or Fluidd as Driver Fan.

When Using the 3‑Driver Duct (E1, E0, X Only)

If you are not cooling all five drivers, you will want to remap your stepper assignments depending on your setup.

For the 3-driver duct I am using:

X → X‑MOT
Y → E0‑MOT
Z → E1‑MOT

Then ensure your printer.cfg uses the correct pins for each axis. (Example mapping shown below — adjust to your machine as needed.)

Keep the [stepper_x] as is.

#############################################

[stepper_y]
step_pin: PD5
dir_pin: PD6
enable_pin: !PD4

[tmc2209 stepper_y]
uart_pin: PD7

[stepper_z]
step_pin: PE6
dir_pin: PC13
enable_pin: !PE5

[tmc2209 stepper_z]
uart_pin: PC14

#######################################

If you are using the 5‑driver duct, no changes are needed. Just uncomment the other driver blocks.

Bill of Materials (BOM)

1× 3‑pin 4010 fan (for board cooling)
1× 2‑pin 4010 blower fan (for driver cooling)
4× M3×18 mm screws (for 4010 fan)
4× M3 nuts
4× M2.5×10 mm screws (for blower + duct)
4× M2.5 nuts
3× M2.5×24 mm screws (mounting the assembly to the printer)
2× zip ties (cable routing)

Print Settings

Walls: 3
Infill: 15%
Material: PLA or similar
Optional: TPU for vibration/noise reduction
Supports only needed on the screw holes on the ducts.

Assembly Instructions

1. Install the 4010 Fan

Place the 4010 fan into the main body.
Secure using 4× M3×18 mm screws and M3 nuts.

2. Install the Blower Fan

Position the blower fan on the mount.
Install the first M2.5×10 mm screw on the side farthest from the drivers.

3. Attach the Duct

Place the 3‑driver or 5‑driver duct onto the blower.
Install 2× M2.5×10 mm screws to secure the duct to the blower.
Install the final screw on the far side of the duct.

4. Cable Routing

Route both fan cables along the underside.
Use the built‑in hooks and zip ties to secure the wiring

5. Mount to the Printer

Use 3× M2.5×24 mm screws to mount the fan assembly and motherboard together onto the printer frame.

6. Connect the Fans

Plug the blower fan into FAN1 (J25) — JST‑XH 2‑pin.
Plug the 4010 fan into COOL‑FAN (J29) — JST‑PH 3‑pin.

Double‑check your voltage jumper settings before powering on.

Modular Cooling Fan Mount for FYSETC Catalyst‑K

0.2mm layer, 3 walls, 15% infill