Please help, strange movement while printing

Hi everyone,

Using Ramps 1.4 board / Prusa style printer ( Marlin 1.1.6 ). Printer has been printing fine, now suddenly while printing the head moves away from the model ( No extrusion ) and then comes back & carries on printing.
It does it on both X & Y direction. This happens every now & again. It does not extrude when it moves away. What could it be causing the printer head to move away like this ?

Thanks
Vaughan

I have had the Same problem when upgrading to Marlin 1.1.X.

And for a long time thought it was firmware, have learned it is stepper data noise. I have mostly eliminated this noise.

See posts here

Have duplicated the errors by removing my controller shield Here

Recorded 4 errors with a short 10 minute video in my 1st attempt
The first error occurs at 1:57 second when the LCD Displays garbage. // not a very good example but still garbage on LCD.
The second error at 4 minutes 20 seconds the filament is ejected in middle of print.
The third error at 5 minutes 30 seconds when the Nozzle moves to the X-Axis end-stop and returns to continued Printing as if nothing happened.
And the forth error at 9 minutes 13 second Filament is ejected again and I stopped the video.

After Shielding install on rare occasions I still experience these kind of errors. Need to prevent the stepper motor noise, causing problems from injecting signals into the LCD controller ribbon cables or completely remove the LCD/SD Card and control using USB cable to PC. I have two 3D Printers and only my 24volt 3D Printer has problems, mainly because of the higher voltage.

Hi Roberts,
You are super hero , thanks so much.

I notice there was plenty of garbage on my LCD screen & just left. Now I realize that you say its the SD card problem. When I print from the laptop it does not happen.
Cool, I find a way I can move the cables away from the wires of the step motors . They all bunched up in one box at the moment. So that's a No No.

Thanks a Ton.
Vaughan

Quote
scubi
Printer has been printing fine, now suddenly while printing the head moves away from the model ( No extrusion ) and then comes back & carries on printing.
It does it on both X & Y direction. This happens every now & again. It does not extrude when it moves away. What could it be causing the printer head to move away like this ?

The LCD has menu commands that can be enabled such as Home X, Y, Z, Change Filament, Pause Print and even cancel print ect.....
When noise enters the LCD Cable It acts like you are clicking on the commands, On my 24volt supply printer I experience the Home X, Pause Filament and Change Filament.

So far none of the movements have messed up a print. Then again maybe I have, just remembered had one Print hanging from the Extruder thought it just broke from the build plate.
It may also have been caused from noise causing a Home Z, this then allows the extruder to crash into the model and wallah Model hanging from the extruder.

i had exactly this happen with a bad sd card. changed the card, it's gone. Maybe easiest fix?

Hi,

I tell you how I solved this troubles if it can help...
I have had garbage on the screen so I shortened and shielded cables, it solved screen troubles but then I had the "strange movement while printing" as described by Scubi...

For safety reason, earth AC wire ( the yellow/green one ) is connected to aluminium frame of printer.
Earth is also connected to GND (or 0V ) inside the switching power supply (most switching power supply are not isolating gnd from earth)
My LCD board was hooked on the frame with metallic screws. So ground(0v) of LCD board was connected to ground(0v) of the power supply through the aluminium frame.
But ground(0v) of LCD board was also connected to ground(0v) of the power supply through cable between ramps1.4 board and LCD board.
So I had a big "GROUND LOOP" !!!
I just replaced metallic screws by nylon screws and nylon rings, in order to isolate LCD ground from aluminium frame, and everything works fine now !
I think that noise due to "ground loop" is more important that noise due to unshielded cable.

Edited 3 time(s). Last edit at 12/17/2017 11:43AM by titi67.