The current idea for the powet bed is two identical square chambers with moving floor. One chamber starts full and one empty, as one is lowered the other is rised and the powder is shifted across. This should create fine layers to work on. This is not a new idea so I hope I can get it to work with plaster. Drawings and photos are to come soon.
Also currently trying to hack various printers to print onto a rigid flat surface but having a lot more trouble with the printheads clogging. It is also looking to be a bit of effort fooling a mid-range Epson Photo printer to think that it is printing to paper. There seems to be light-sensor on the printhead that will not allow a print unless the paper is there. Also there is an army of switches that need to be activated at the right time to trigger the print. It is almost looking easier to replace the printer electronics with a custom inkjet driver.