Build manual says "move IR sensor as low as possible". So it' s a centimetre or two below the nozzle. Later you do the first Auto Home with Z offset set to "-5mm". So the nozzle is then a LONG WAY above the glass plate. Then you are supposed to move the glass bed up until it touches the nozzle, in 0.1mm increments. I can move it up 5mm. But no more. So the bed is still a long way from the Nozzle? What to do?
I have a dual, so I can't be certain about commissioning yours. I did have a similar problem and, after a searching on the forum, turned the lead screws by hand to get the level where I needed it.
The IR sensor needs to be higher than the nozzle. Like 1-2mm, not cm. ie: if you're raising the bed, the nozzle would touch before the IR
Had this same issue. I've never gotten the offset to work properly. Waiting for a youtube video of the process I just adjusted mine manually, which I'm used to from the Robo3D R1.
OK I think it's sorted now guys. It's just very unintuitive. You have to set the offset LOW (like the -5mm suggested in the manual) in order to then be able to raise the bed towards the nozzle (after an autohome). Doesn't seem to be another way of doing it. Otherwise it blocks. Then you can enter a new Z offset, after a calculation, but then, after the next auto home, that will not bring the bed up to where you had it (touching the nozzle) but a little way off. The confirmation that the the BB has understood what you want comes when you crank the bed up manually and when it displays Z=0 then the bed is touching the nozzle as you wanted it. Grrr.
haha is there a guide somewhere to our firmware somewhere, written in a way that makes sense for the BB implementation?
I don't know about a guide, but Richard Caunt has already modified it and supplied some details. I forget whether that was here in the forum or on G+. He altered the orientation of the dial rotation, increased bed movement speed, and a couple of other things.