3D printer - installing a BLTouch clone part 2
Oh dear. I spent around half of my Sunday recalibrating my bed based on the probe output pasted into a spreadsheet. One part I didn’t consider was that the Y coordinates were inverted - the first line of points was the front of my bed but I assumed it was the back of my bed. My failure to validate my assumptions caused a calibration error of 0.9mm by the end.
To give the BLTouch credit, it didn’t fail to print with this configuration. It just had some significant issues, as you might expect. Unfortuantely, after another day of calibration, the output would show it was near level but the prints would still come out with a middle sag. My bed is glass, so it’s very flat, some slight lift at the corners… why’s it sagging so much?.
I believe BILINEAR bed levelling was the root cause - this is good for beds with warps but my glass bed is quite flat. I believe my X carriage isn’t very secure, causing a higher error rate on one side. I see why the Z limit switch is used. Eventually, I issued an M500 and reset my Z probe offset before manually levelling my bed by sight. Within two prints, my bed was perfectly level again.
I would say that this experiment was a waste of time and money for my configuration. Not only did I waste time failing to understand some output, but I ended up returning to my previous levelling setup. If I felt the urge to return to this experiment, I would probably reflash my firmware with LINEAR bed levelling enabled. It seems more suitable for my unique configuration.
I’ve decided that the noise is too much, so I’m buying new stepper drivers. I spent a while looking for good drivers before finding the drivers I wanted paired with a 32bit mainboard to erase my Octoprint USB jitter. I purchased it immediately. When it arrives, I’ll likely revisit this configuration, as the installation process promises to be challenging.