Just finished building a printer of my own design. Nothing unique.
The X-Y plane is fixed and Z is up and down. Height is gained by lowing the platform.
I am using a Printrbot Rev D board and every time I start a print the platform goes up about 5mm.
I would like the first movement to be down 5mm.
Using Repetier Host and Slicr and have added G28 to start code.
Do not know G code but have tried to change Z movement in the code to negative with no luck.
Any ideas?