It’s been an interesting couple of days. 1st, after dialing in my new BLTouch, I decided to redo things a bit. Someone posted that it helps to dial the bed springs up tight, then loosen them a couple of turns. Sounded like a good idea.
1st problem: after powering up & trying to AutoHome, the printer tried to drive the nozzle to China. Fortunately, I hit the power switch before any damage was done – the glass didn’t even break. I tried cycling the power a couple of times, with my finger hovering over the power switch. Good thing: I had to quickly power off both times.
Then, I realized that the BLTouch wasn’t powering up, nor the LCD. Opened up the power chassis, reseated the breakout board 3 times (until I finally got a normal display instead of a blank screen).
While I had the power chassis open, I decided to replace the ribbon cable that links the control board to the display, because the original 1 was being stretched just a little after I moved the LCD Display unit up to make room for the storage drawers underneath. I wanted to give extra length because I’m thinking of redoing the drawer unit to make the drawers a little taller & probably add 1 or 2 more drawers. These ribbon cable connectors are a real PITA to dissassemble, but I’ve done it a number of times in the past, so I knew what I was in for. On the positive side, the new ribbon cable worked 1st time
Next was to dial in the Z Offset again. I reviewed a couple of YT videos to see if they had any tips or tricks I wasn’t aware of.
I ran into a problem. I used Pronterface to talk to the printer. I issued a G28 to AutoHome the printer. The X axis moved all the way to the right, as expected, then started to move back on the Y. However, something weird happened: the hotend moved about halfway back then moved forward & left as if it was moving to the center to home the Z axis using the BLTouch. Unfortunately, it didn’t stop at the center. It kept moving left & forward until it started to bang into the front cross rail. Power button time again. Tried it again a couple of times. Then, I stood up from the chair I was sitting on & noticed something. The cable that links the hotend to the control board had flopped over to the rear of the printer and, guess what, it was being pushed into the Y axis limit switch. So, a note to the wise… Also, it seems like a good argument for a cable chain.
I flipped the cable back up where it belongs and AutoHoming started working properly again. I did the paper trick to find the Z Offset value, then printed a few of the 20mm X 20mm 1-layer squares, adjusting the Z Offset before each print. Got it dialed up pretty well, but the squares were coming out a little thick, so I reduced the flow rate from 98 to 95.
That’s about it for now. So, watch out for little things like cables flopping over, and axes moving where they don’t belong.