@deckingman thanks for your time and dedication on the repply. I am planning to add some cork sheets on the underside and probably a heater for the chamber in the future for more complex materials. my mirror bed was 4mm as it was only supposed to "flatten" the bed (I was unable to find a good aluminium tooling plate on my country, ended up using a regular aluminim plate) and was actually reused from my home. this printer is only for large projects so I dont mind giving a full hour of cooling down after a 3 or 5 days print. for smaller projects I use a 200X200 printer.