How to set up an Ender 3 Pro with BL Touch?
Preface: I am new to 3D Printing.
I bought an Ender 3 Pro, set it up and, without doing any adjustments, ran a print from the memory card supplied. It went well. Nice and smooth.
My motherboard has 4.2.2 printed on it and my BL Touch is v3.1. Firmware from https://forums.creality3dofficial.com/download/ender-series/ender-3-pro/
I installed a BL Touch - admittedly very fun, using the many variations of instructions online -
* Hardware first
* Flashed firmware (not 100% sure I got the right one as the Enter-3-Pro-v4.2.2 Marlin2.0.1-BL-Touch-V1.3.1 makes my LCD screen beep continuously whereas the Marlin2.0.1-BL-Touch-V1.1.2 does not. I have not tried the "Ender-3 Pro Marlin1.1.6-BLTouch V3.1" option, maybe I should)
* Added G29 to Cura for print instructions to run BL Touch bed level
* Ran through setting up offsets - again, using the many variations of instructions. As I'm new to all of this, one set of instructions led me to score the bed a bit with a hot nozzle. Eventually got it to lightly grip some paper in each of the corners. Stored the settings.
The prints started by basically dragging the nozzle so close to the bed that it barely extrudes anything. So I adjusted the Probe Z Offset to 0.1mm higher, which prints better, except in the middle-right of the bed where it barely extrudes again.
I've run through levelling the bed in the corners and at various points using paper and the adjustment underneath, then confirmed with auto-home and probe z offset. I did think that the whole point of the BL Touch was to avoid having to do this step though. I may be mistaken.
The same thing happens -- middle right seems higher and thus less extruded filament. The bed still appears to be flat - checking with a straight edge shows no visible light across it.
I'm testing bed level using a bed level model from thingiverse: https://www.thingiverse.com/thing:3244876
I bought and fitted a glass bed. This had no noticeable difference, so I don't think the bed being scored was the issue. Then I found out that the supplier has their own firmware, so I loaded that on. Re-set bed level, re-set the z-offset, etc... it was still printing all but middle-right for the first few layers.
Physically levelled the bed. I put the machine as level as I could get it and tightened / loosened each of the bed screws until it was level (to within a 0.1mm or so) back to front, left to right, and both diagonals.
I still feel as though I shouldn't have to get the bed perfectly level as I thought this is what the BL Touch was for, and if I have to dial it in so accurately, what does the BL Touch actually do other than flash pretty colours?
After physically levelling everything, it is a much better print but the front two corners are struggling to extrude the first layer or two, so if I were to tilt the bed forward (lower the front), this may resolve itself assuming the BL Touch doesn't then compensate.