Once I had the retired Geeetech A10 3D printer powered up, I could start poking around to see what is working and what is not. Obviously the control panel was my entry point to jog each axis. I was very happy to see the individual motors move on command, but I couldn’t command a homing cycle just yet due to the missing Z-axis switch.
However, the control panel itself was annoying to use. The screen contrast was poor, and user responsiveness is lacking. I frequently find that encoder steps were ignored, as were some of my wheel presses to select menu options. I experienced the same frustration with the Monoprice Maker Select, and I had thought those issues were specific to that printer. Now I’m starting to wonder if this is common with 3D printers running Marlin on a ATmega328 control board.
The good news is that I don’t plan to interact with the control panel for much more than this initial test. Once I established the board was functional, I no longer feared the USB port damaging my computer so I found an appropriate USB cable and plugged it in. The expected USB serial device showed up. With the popular settings 250000 8N1, I could command the printer via Marlin G-code. This is how I intend to control this machine as a three-axis motion control platform.
I didn’t intend to use the control panel anymore, and I could have just left it alone. But it also sticks out to the side of the printer and awkwardly taking up space. After a particularly painful meeting between a body part and an outer corner of the panel, I took a closer look at how it was connected to the control board. It seems to be a single ribbon cable plugged into a single connector that had two dabs of hot glue to help keep it in place.
I removed the hot glue and the cable to see if this printer would continue functioning as a USB serial peripheral, in the absence of the control panel. Good news: it does! I could move all three axis (X, Y, and Z) via
G0 commands. So after removing two M5 bolts, the control panel go live in a box. Cleaning up the printer outline and hopefully reducing painful episodes in the future.
Now I need to install a replacement Z-axis homing switch in order to try homing cycle.