Qidi tech Plus 4 4020 fan upgrade

This was made to help with heat break cooling and lower noise. As the original fan we very annoying to listen to. Unfortunately some QoL had te be sacrificed for this to work. like now having a fan connector to deal with and the cover mildly interfering with the hotend cables.  

Parts list

• Noctua NF-A4x20 (PWM): https://noctua.at/en/nf-a4x20-pwm (Note: PWM does not  matter because the plus 4 only has 2 wires for the fan. so he the cheaper version)
• Mini DC-DC Variable Step-down Buck Converter 0.5A (https://www.amazon.com/Remote-Controlled-Aircraft-Converter-Step-Down-MP2307/dp/B0DSZBNSLJ)
• 2: m3x10 bolt 
• 1: m3x20 bolt
• Heat resistant material like: ABS-(CF/GF)/ASA-(CF/GF). > 100C. (I used: Siraya Tech Fibreheart ASA-GF TDS)
• Dubble sided tape for the buck coverter
• 2: 4x3mm magnets (4mm diameter 3mm long)

Print settings (To modify)

• Auto tree supports: Hybrid (Required)
• Modifier Parts (Required)
  • 0 Perimeters 
  • 0 Top layers
  • 0 Bottom layers
  • 20% Triangle infill (Avoid using 3D infill)
• 7 Perimeters (Recommend)
• Variable layer height of 0.2 (Recommend)

To get the triangle vents import the main parts first ("4020 Fan mod A/B"). Then for each part import the corresponding letter A/B ("4020 Fan mod Tri-mod A/B") separately. Make sure to print "Part A" on the side face. 

Add the “Modifier Parts” print setting to the “Tri-mod” modifiers. You might have to move the modifier parts vertically to make them overlap with the parts correctly.

Assembly

Fan Wiring

Start by removing the original fan and bracket. cut the original fan leads and make sure you have plenty of length. Cut the Noctua fan black and yellow wire in 2, make sure to have ~50mm of wire on the fan side. Solder to fan-side cables to the output of the buck converter. (The green and blue wire are redundant here.) make sure the green and blue wire are short enough to not short anything. Solder the connector-side. 

Tool head Wiring

Next use the included “mod adapter thing” included in the Noctua fan box and the orange “connector ball”. Put the black wire in one and the yellow and red (from the toolhead) in the other. and squeeze them to lock the wires in place.

Putting it together.

Slot the fan in the “A part” on the bottom open side. Use 2-sided tape to stick the buck converter somewhere on the front-inside. Avoid the closed side for clearance reasons.

Add the 2 magnets (1 for each part) to the features with a 4x3mm hole. To the bottom-rear of both parts.

Screw the “B Part” to the rest to lock the fan. Use the m3x10 bolt for the top 2 holes and the m3x20 for the bottom one.

Installing

Connect the the fan to the tool head and put the cover on. (Just like to original). Make sure to dodge the hotend power en and temp-sensor cables.

You should be done! Happy Printing.

PS: This is my first tutorial so its probably rough around the edges. Feedback would be welcome.