I wanted to have a cover for my UM2 extended + to have a closed compartment for ABS printing. I made one from 6mm phenolic or "Pertinax" with white outer color which I got cheap from Ebay (20 Euros for all). It is very sturdy and can be milled easily. It was milled with a 1.5mm mill. The connection is like the Ultimaker, with Tabs and screws, I adopted the same method. This gives a very stable casing which fits very perfect on the UM2. On the pictures the Polycarbonate windows are missing, I milled these from 8mm PC. Update: I added a temperatue controller (Inkbird ITC-2000 ) and made a case for it. The files are here too. It show me the temperature at print head height. If necessary you can add a small fan to it which starts to run if the case interior gets too hot.