Printer Head Can't Find Home

[larryalc 1]

Problem: Printer head would not center on the build plate. Once a print started it would go off to the side and hit the right wall making a horrible noise. It would also not “Home” (X axis) through the "Advanced" option on the unit control panel.

Solution: Through a couple of other posts in the community all of problems pointed towards the end switch. I checked it, the X-axis switch clicked like it should. I turned off the printer and physically moved the head to the center of the plate. I then got into Pronterface (this was a life saver) and drove the head in all directions while monitoring Pronterface’s chat screen. Sure enough, every time I tried to drive the head towards the –X direction (home end switch) I would get a message back from Pronterface saying that I hit the end switch – I was still in the middle of the build plate. That told me I had a bad end switch.

Well, long story short, I cut the X end switch out…still had the problem. I opened the bottom of the control panel and pulled the X axis end switch control plug from the controller (blue wires) – problem solved!!! So, somewhere there was a short in the wiring.  I pulled the left side of the printer off and found the X end switch wires (blue wires) pinched between the extruder motor and the case. Pulled the wires out, repaired the insulation, and now runs great!

Cause: A couple of days before the problem occurred I did some stupid things. I tried to switch different PLA reels, simultaneously, while running a build. This jacked up the extruder. I couldn’t get the material out of the extruder so I pulled the extruder apart. This disengaged the internal servo motor. I did a “touch and feel” to realign the extruder and internal motor so that I didn’t have to open up the cabinet. In the meantime, the X-axis wires (internal with the motor) got caught in the reassembly… and thus the pinch. Everything worked fine for a couple of days because it took that long for the heat of the motor to finally break down the wire insulation so that it caused a short…and the constant positive end switch signal.

I'm a newbie, so this was fun to investigate and learn more about the printer. I did several very successful builds until this problem. I’ll probably screw up a lot more in the future with experimentation, but that’s the fun part! This is a very nice machine.

[123bob 0]

Thank you for this post!

I too was having x axis homing problems after having installed an Olsson block and |Robert|'s feeder. I found that I had accidentally caught one of the x axis switch wires under the feeder motor. It also took a couple of days to fail.

What was different in my case is that only one of the wires was pinched against the motor. The switch ohmed out fine so I was baffled. What was happening is that the wire was shorted to ground on the feeder motor case. This had the effect of making the machine think the switch was activated all the time.

Your post made me look further into the wiring and I found the short to ground.

Pulled the wire loose, taped it up, reassembled carefully, and now she works just like new! Whoo-Hoo!

The symptom it was showing is that when I would make the head "home" using the maintenance menu, The x axis would not move home. It would hop to the right about 1.5 cm. It would keep doing this with every homing attempt. Eventually it would have ran into the wall on the right side.

Thanks again,

Bob