Random/eratic axis movement/homing during print...FIXED

Hello,
I have been having a problem for the past several months to where, during a print, the printer would pause and either the X or Y axis would move to an end position and then resume printing again. Usually it would return to where it started, so no big deal. But sometimes it would not return to the correct spot and the print would be ruined. More recently, the extruder started behaving like this, which would drive the filament out of the extruder and ruin the print.

This problem seemed to be common enough that a lot of people have it, but not common enough that everyone knows what is causing it. It is also not common enough to even have a fancy name. Like "z wobble", or "over extruding" or something. People don't know what to call it or how to describe it. That makes it very time consuming searching the forums for an answer. That is why the title of this post is worded the way it is, to try to capture someone's search.

I would like to start a new/fresh conversation about the issue and the suggested causes, and ultimately what I did to fix mine. Please feel free to comment on if you had the issue and how you fixed yours. But here are the most common suggestions I could find, and my thoughts on each.

1) The end stop switch wires are too close to the motor wires which induces a false endstop signal. So the wires need to be spread apart from each other.

This is the first 'fix' I read. To test this theory, I started a print, and during the print I would manually activate an end stop switch. Nothing happened. When I pressed the X or Y end stop switch, there was no affect. I took this to mean that even if a signal was induced into the system, it wouldn't do anything. Now I do realize that different printers use different electronics/processors. Mine is a Reprap using an Arduino and a RAMPS board. Maybe a different printer would react differently, but to me this does not seem to be an issue for my printer.

2) Check the G-code.

The problem is completely random. If I restart the print, if may print fine. If it's in the g-code, it would fail the same every time.

3) Change the SD card (assuming you are using one. I am.)

This was the first thing I actually tried. When I first got a printer I was told to only use a 2GB card. I could only find a 4GB, and it worked. But with the problems I thought that maybe this is why I was told to use a 2GB. I ordered one online, and the problem got better. Maybe. It's hard to tell if a random problem is better. But it still acted up. Better or not, I still had a problem.

4) Put a ferrite bead on the ribbon cable from the LCD controller.

This is the next thing I tried. And problem solved! Before this, the printer would not print 30 minuets without 'acting up'. I have now printed 4 parts, each taking 5 1/2 hours with out a single glitch or hiccup. I used snap-on RF chokes from Radio Shack part number 273-0104. There are two in the bag, which is perfect, because there are two ribbon cables. The instruction say to fold the cable in half, and wrap around the choke once.

Please view the pics of the installation. In my opinion, this is the best thing you can do to your printer if you are using an LCD controller. I don't have to baby sit my printer any more. I can start a long print and trust it to not screw up.

Again, feel free to make other suggestions, and if any of the other suggestions fixed yours, or if you know of another fix to this issue. Or any other thoughts, concerns, or comments.

Thanks for your time, and I do hope this helps someone,

Same problem here, probably eletromagnetic interference as well, I tried printing straith from computer and worked

I have experienced this early last year, believe the issue for me was somewhere between the slicer "in my case slic3r" and ejecting the SD card from the PC. when viewing the gcode came across a few corrupted lines too massive section of gibberish with in the gcode file.
I can rule out " 1) The end stop switch wires are too close to the motor wires"....

endstop and motor wire share the same slot in the beams and never presented problem....

"2) Check the G-code.
The problem is completely random. If I restart the print, if may print fine. If it's in the g-code, it would fail the same every time. "

This makes me wonder if you had couple of exposed wires shorting on each other, when you added the ferrite bead you managed to separate them.

"4) Put a ferrite bead on the ribbon cable from the LCD controller."
am just not convinced this is the solution dont get me wrong it want hurt, but if that was the main problem there be a lot more of us raising this issue.

Edited 1 time(s). Last edit at 05/18/2018 04:40PM by jinx.