I don't see this topic addressed anywhere so I'll ask what I hope is a new question. My I am setting up a homebrew printer roughly based on OrdBot frame and Repetier firmware / Host. The bed is nearly level, but of course never completely so. I am at the point now where, when extruding a "raft" (I think it's called) to begin printing a part, the extruder has a difficult time finding the Z=0 height. When I place the extruder at the proper height and power cycle to set this location as 0 in the firmware / Host software, it of course moves to another X/Y coordinate to begin printing. At this point, the extruder drops down and either scrapes the blue tape or digs into the bed.
(1) I "think" (this is actually a question) I need to know how to level the bed? I've done a "Config / Level Delta / set P1 P2 P3 points", "Calculate Leveling", and M500 Store to EEPROM. This doesn't appear to be sufficient. What else do I need to do in this area?
(2) How do I tell the firmware / Host software where Z=0 is? I don't have a Z probe, this doesn't seem to be a necessity, is it?
Thanks again for your help.