I designed a tool box for  maintenance of the Centauri Carbon.

When assembling the box, put the two halves together and slide a piece of 1.75mm filament into the hole. You may need vise-grips on the filament depending on your print profile/machine settings. You can then heat some thing like an Allen wrench or nail to melt the filament/hinge pin in place.

I have posted the CAD files @ https://www.printables.com/model/1414484-elegoo-centauri-carbon-toolbox

Please feel free to customize this box to suit your needs.