Sadly the materials in the lack changed over time, the insides are basically just cardboard honeycomb with a thin veneer around it.

So if you want to follow the lack mods on the web, especially ones written in the 2010s, you need to make sure you strengthen the legs to accommodate the hardware

Server rack? That’s a 3D printer enclosure!

https://www.printables.com/model/76318-ikea-lack-enclosure-3...

I love Lack, really versatile piece of furniture/equipment! Not lacking at all :)

server lack