I wasn't happy with my initial top cover designs but I want one since day one. It's quite cumbersome to clean or remove the dust every once in a while from all the motion parts and connectors on top so I want mainly top cover to solve that. Of course it should help with chamber temperatures but to be honest that's not my main goal anyway (to print like in a chamber with +100°C) 

My initial designs: 

https://hackaday.io/project/175489-changer-a-toolchanger-new-interpreted/log/195964-mixed-opinions-topcover-design

My new approach:

The new top cover should consist of seperate portions which can be sticked/glued together. I've designed to not use sheet metal parts because I want to itegrate some latches/hinges in the front and backpart to easily access the top area of the printer to maintain, check tools or change tools. 

This cover is stil a mockup to play with the design before I'll fully redesign the top cover with individual segments. Of course the acrylic panels are missing in the design as well but in the end there will be 5mm acrylic side panels as well.

Top-view:

I tried to include design elements from the mainstructure and merged it to the top. One example is the groove which represents the 3060-Extrusions from the base-assembly.

In the end my main goal is that you can open the front panel of the top cover (hinged) but I still have to think of the propere hinge type for that. Maybe I'll design my own with a rasting-feature to ''lock'' the front panel in place.