BTT SKR Pico 4010 Fan mount

Later edit: I have added a 20mm tall version i prefer the 25 because i can easily remove/insert the Neopixel and Det Plug 

for the 20mm version you will need M3x25mm instead of M3x30 

If you want to but this Board here is an affiliate link http://shrsl.com/4t601 and you wil support our work 

Item Description: SKR Pico 4010 Fan Mount

The SKR Pico 4010 Fan Mount is a specially designed bracket that allows you to mount a 40x40x10mm fan onto your SKR Pico 3D printer controller board. The fan mount is specifically designed to keep the MCU cool even when using a low noise fan. It is made from high-quality, durable materials that are able to withstand high temperatures and vibrations.

BOM (Bill of Materials):

• SKR Pico 4010 Fan Mount (1x)
• M2.5 screws (4x) - for mounting the fan mount onto the SKR Pico board ( I use M3 see below)
• M3x30mm or M3x25mm screws (4x) - choose the appropriate length based on the mount you're using
• M3x16mm or M3x25mm screws (4x) - choose the appropriate length based on the fan you're using (16mm for 4010 fan, 25mm for 4020 fan)
• 40x40x10mm fan (1x) - not included with the fan mount, but can be purchased separately
• M3 tap - for increasing the mounting holes on the SKR Pico board (if necessary)

Assembly Instructions:

1. Begin by gathering all of the necessary parts and tools.
2. If the mounting holes on your SKR Pico board are not already M3, use the M3 tap to increase the size of the holes. This will make it easier to mount the fan mount onto the board.
3. Place the fan mount onto the SKR Pico board, making sure that the mounting holes line up with the holes on the board.
4. Insert the four M2.5 screws into the four corners of the fan mount and tighten them down securely.
5. Insert the four M3x30mm screws into the four corners of the fan mount and tighten them down securely.
6. If using a 4010 fan, insert the four M3x16mm screws into the holes on the fan mount and tighten them down securely. If using a 4020 fan, insert the four M3x25mm screws into the holes on the fan mount and tighten them down securely.
7. Attach the fan onto the fan mount using the screws that came with the fan.
8. Connect the fan wires to the appropriate headers on the SKR Pico board.

Your SKR Pico 4010 Fan Mount is now ready to use!

This SKR Pico Board its Mainly use with Klipper Firmware

here its a config section to add for this fan mount

[temperature_fan controller] 
pin: gpio20 
control: watermark 
max_delta: 3.0 
sensor_type: temperature_mcu 
sensor_mcu: mcu 
min_temp: 0 
max_temp: 85.0 
target_temp: 35.0 
max_power: 1 #for 100% 
shutdown_speed: 1.0

Here's a breakdown of what each parameter does:

[temperature_fan controller]

This specifies the type of fan controller being used.

pin: gpio20

This specifies the pin on the SKR Pico board that the fan is connected to.

control: watermark

This specifies the type of fan control being used. Watermark control is used when the temperature being monitored is compared to a set target temperature.

max_delta: 3.0

This specifies the maximum difference between the target temperature and the actual temperature at which the fan will run at full power.

sensor_type: temperature_mcu

This specifies the type of temperature sensor being used.

sensor_mcu: mcu

This specifies the specific temperature sensor being used, in this case the MCU temperature sensor.

min_temp: 0

This specifies the minimum temperature threshold at which the fan will turn on.

max_temp: 100

If the temperature of a heater exceeds its configured max_temp value, the firmware will trigger a shutdown and the printer will stop operating. This is a safety feature that is designed to prevent damage to the printer or potential safety hazards.

target_temp: 35.0

This specifies the target temperature at which the fan will start running.

max_power: 1 #for 100%

This specifies the maximum power that the fan will run at, in this case 100%.

shutdown_speed: 1.0

in Klipper firmware, the shutdown_speed parameter is used in the fan control configuration to specify the speed at which the fan will run when the printer is shutting down.

When the printer is shutting down, the fan will continue to run until the temperature has dropped below a certain threshold. The shutdown_speed parameter allows you to specify the fan speed during this shutdown process. A lower value will result in a slower fan speed, while a higher value will result in a faster fan speed.

For example, if you set shutdown_speed to 0.5, the fan will run at 50% power during the shutdown process. If you set it to 1.0, the fan will run at 100% power.

Note that the shutdown_speed parameter only applies during the printer shutdown process. When the printer is running normally, the fan speed will be controlled based on the max_power and max_delta parameters in the fan control configuration.

Shutdonw mean when the printer has a problem not turned off ;)

This configuration should work to turn on the fan when the MCU temperature exceeds 35°C and turn it off when it drops below the specified threshold. With a delta of 3°C

These are additional parameters that can be configured in the fan control section of the Klipper firmware:

cycle_time: This parameter specifies the duration of one cycle of the PWM signal that controls the fan speed. A shorter cycle time results in a higher frequency signal and can provide more precise control over the fan speed. The default value is 0.0010 seconds, which corresponds to a 20 kHz PWM signal. Setting cycle_time to 0.0005 seconds will result in a 2 kHz PWM signal.

hardware_pwm: This parameter can be set to True to use hardware PWM to control the fan speed. Hardware PWM is generally more reliable and provides more precise control over the fan speed, but it may not be supported by all hardware.

kick_start_time: This parameter specifies the duration of a "kick start" signal that can be sent to the fan at startup to help get it moving. A longer kick start time can help ensure that the fan starts spinning reliably, but it may not be necessary for all fans.

max_speed and min_speed: These parameters can be used to specify the maximum and minimum fan speeds that are allowed by the firmware. These values are specified as a percentage of the maximum fan speed. For example, setting max_speed to 0.8 and min_speed to 0.1 would allow the fan speed to vary between 10% and 80% of the maximum speed.

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