Made this to go below morganlowe's raspi 4 case, to hold my Intenso 128GB SSD which I use to boot my Pi from that runs Home Assistant. I left some space for cooling and screwed it into the wall with some wood screws.
Print bracket once, holder twice.
Here's the onshape model so you can modify it if you want. https://cad.onshape.com/documents/fc7ceb793b56584adb7f316f/w/e7ad0b31f7005c5372a292cf/e/a07f86426859f650c3ac2fa7?renderMode=0&uiState=6227a436a839ed51f36983be