I'm slowly taking apart my retired Canon Pixma MX340 multi-function inkjet, and I've wrapped up my second pass examination of control panel electronics. Now I will switch attention to its paper feed motor assembly. First of all, calling it the paper feed motor is an understatement, I just don't have a better name. Looking at gears and shafts on my first pass, I knew it is linked to several other mechanisms beyond feeding paper. I got a close look at how it can open the paper tray door at the front of the machine, but everything else is still buried out of sight at the moment.

They are still buried because I paused physical disassembly in order to ensure the machine remain in a running state. This was very useful as I probed electronic control and communication signals while it was running live. I gained far more insight this way than I could have if I couldn't run the machine. I learned a lot about the document feeder, the scanner, and how the main board communicates with the control panel. After all that, though, I'm close to exhausting everything within my current skill level to understand. But I think there's one or two more things I can do before I pick up the screwdriver again.

I want to record paper feed motor mechanism's behavior. I can see with my eyes it turn forward and backwards multiple times at different speeds. There's a sequence that runs upon power up, another one when it goes into standby, and naturally there is much more when the machine prepares to actually put ink on paper. I want to quantify that motion more precisely than what I can see with my own eyes. This way, in the likely event the machine stops running as a result of future disassembly, I have something to reference. Correlating them with mechanisms that probably won't run by the time I disassemble the machine far enough to get to them. I need to quantify exactly what I want to record, then go look for tools that can help me do it.

This teardown ran far longer than I originally thought it would. Click here to rewind back to where this adventure started.