About 3 months ago I purchased my BW from a friend who purchased it from a YT reviewer here in Australia. The reviewer didn't have a lot of nice things to say about the printer and commented about how it did really poor quality prints.
My friend spent some time messing around with it but he also has about 6 (no, I'm not joking!) other printers that work flawlessly, so he didn't want to spend the time with a problem machine, especially as one of his printers was a CR-10 and they are fairly comparable printers. So it gets unloaded to me as he knew I was struggling with the print volume of my A8 (I do LOVE my modified A8 though)
When it comes to time, I don't have a lot of it spare, what with running my own automotive business and my family. So, I've had the BW for about 4 months. Never ONCE got a decent print from it. My issue was always the bed levelling and Z offset. Combined with a lack of knowledge about this printer (remember it was already assembled?) it took me months of spending 5-10 minutes here and there to figure out how to calibrate this damn thing.
But I did it. Today, I stumbled across a .pdf which showed me how to do an "initial" BLTouch calibration and lo and behold, it laid down a PERFECT first layer on my test cube.
I still have to figure out what the deal is with the bed levelling. But I believe thats all to do with it where it believes the BLTouch is located compared to where it actually is. Because once it begins to measure the last row at the back of the bed, the BLT just misses the bed and consequently attempts to drive the carriage through the bed, through my desk and out the otherside of the earth.
I've managed to overcome it for the moment by waiting for it to home X and Y and then literally forcing the bed back about an inch.