Quiet PSU shield for Sovol SV06 (Plus) ACE

This is a replacement shield for the power supply unit used in the Sovol SV06 ACE and SV06 Plus ACE printers. (This model is essentially a companion build to the MCU shield.) They come with a cheap chinese-made 400W PSU which, while working fine, is fitted with a fan that is about as loud as a vacuum cleaner and also always on. (I.e. its thermal design isn't even that bad, but the acoustic design is terrible.)

This replaces the case shield by one that allows to use an external 80mm fan and (optionally) a 2596 step-down module to reduce the fan's RPM. The model file prints fine with 0.2mm line height and a standard 0.4mm nozzle and needs no supports.

What you will need for the build:

1. The printed PSU shield (I recommend using PETG, though PLA should be fine).
2. 6 M3x4 melt-in nuts for the case screws (the existing screws should work fine).
3. 2 M4x5 melt-in nuts for the fan.
4. 2 M4x35 screws for the fan (I recommend brass, but other materials should be fine).
5. A quiet 8025-type PC case fan of appropriate voltage (24V or 12V when using the step-down module).
6. A simple 80mm fan grill; I used this one.
7. 2 M3x4 melt-in nuts for the step-down module (optional).
8. 2 M3x5 screws for the step-down module (optional).
9. 1 LM2596-type step-down converter module (optional).

Also, if you do not want to damage the existing case shield and fan, you'll need a  cable with a JST-XA (2.5mm) plug. Those can be hard to find, so a JST-XH will do in a pinch,  after you cut off its friction latch. XA uses a different locking mechanism but is otherwise similar. (It might then be wise to hold the connector in place with a small drop of hot glue, however.)

If you want to use the LM2596 module and a ready-made cable with a JST connector: take care of the polarity, as this is not standardised, and that small buck module will fail in a rather melodramatic (and permanent) fashion if you connect it to -24V.