Stop half way printing & Layers shifting

Hi,

Recently I am having trouble of my printer stops half way printing. I suspect it is something to do with the connection because it dosnt always stop at the same spot and sometimes if I am lucky, I can get the same gcode file printed...

Also I sometimes, the layers are being shifted.. the range can vary between a few mm to even 1-2cm!

I am using Ponterface ad marlin, any ideas would be much appreciated.

Cheers,
Adrian

Edited 2 time(s). Last edit at 03/27/2012 05:05PM by ahbtsang.

If you're using Marlin, it's probably stopping because your electronics stop detecting the thermistor, so it shuts down the extruder. Does it output warnings about temperature protection? In any event, check your connections. Shifted layers are caused by skipped steps on the motor that controls the axis along which the print shifts. If the affected axis has too much friction, reduce it somehow (smoother rods, more appropriate bushings or bearings, better bushing alignment, more lubrication, etc). If after that the motors still aren't getting enough current to overcome the amount of friction, increase it and provide active cooling for the stepper motor drivers. If the motors still aren't capable of putting out enough power to overcome the friction, get better motors

Thanks for your quick reply and info.

About the stopping:
the printing process stopped suddenly and there weren't any messages displayed in the ponterface console. Thermister being disconnected could be a cause, but I doubt it because after it stopped, I couldn't disconnect and connect or restart ponteface... I had to unplug the usb, exit ponterface and start everything again... I'm sure that I didn't touch any other cables apart from the usb...

Shifting layers,
Again the shifting problem came at random times.. I know a reason may be the motors skipping steps, but I forgot to mention, when a layer shifted, it shifted in both x and y axis.. and during the whole shifting process there weren't any strange noise. It just happened smoothly! Right now I am using linear bearing for x and y axis, when the power is off, both axes could move easily so again I doubt it is the friction...

any other ideas??

many thanks.

ahbtsang Wrote:
-------------------------------------------------------
> Thanks for your quick reply and info.
>
> About the stopping:
> the printing process stopped suddenly and there
> weren't any messages displayed in the ponterface
> console. Thermister being disconnected could be a
> cause, but I doubt it because after it stopped, I
> couldn't disconnect and connect or restart
> ponteface... I had to unplug the usb, exit
> ponterface and start everything again... I'm sure
> that I didn't touch any other cables apart from
> the usb...

Sounds like USB problems. What's your host OS and electronics? Does the USB cable you're using have a ferrite ring around it?


>
> Shifting layers,
> Again the shifting problem came at random times..
> I know a reason may be the motors skipping steps,
> but I forgot to mention, when a layer shifted, it
> shifted in both x and y axis.. and during the
> whole shifting process there weren't any strange
> noise. It just happened smoothly! Right now I am
> using linear bearing for x and y axis, when the
> power is off, both axes could move easily so again
> I doubt it is the friction...

This could still be the driver boards overheating and shutting down for a moment. If you point a fan at your electronics, does the problem reproduce?

Are you plugging in any other powered devices to the wall socket near the printer as power spikes from power tools can do this

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__________________________________________________________________________
Experimenting in 3D in New Zealand

NelsonRap Wrote:
-------------------------------------------------------
> Are you plugging in any other powered devices to
> the wall socket near the printer as power spikes
> from power tools can do this


That's a good point. I've had a printer stop dead in its tracks when I ran a paper shredder plugged into the same outlet.

Pointedstick Wrote:
-------------------------------------------------------
> NelsonRap Wrote:
> --------------------------------------------------
> -----
> > Are you plugging in any other powered devices
> to
> > the wall socket near the printer as power
> spikes
> > from power tools can do this
>
>
> That's a good point. I've had a printer stop dead
> in its tracks when I ran a paper shredder plugged
> into the same outlet.

Mine skipped when I started a power saw on the same circuit

---

__________________________________________________________________________
Experimenting in 3D in New Zealand

My gen6 machine will skip steps due to power surges. Also bright light does strange things (optos).

It used to do the shutdown mid print thing but it typically gave an error...something like "linenr not lastline +1" I think. I have had the issue less since I repositioned my USB, power, stepper and endstops. It seems noise was the primary cause of this issue. That printer is about 95% solid now (and I am using Marlin from October or so). Combination of noise and too high of acceleration were my primary issues.

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Thanks for all the suggestions, I believe it has something to do with the board.. the wires came with the endstops were too short and so the only suitable place to put my electronics was to cable tie it to the A frame.. recently it kept sliding so I suspect this is causing the problem... I don't have time to try out other possibilities yet, but I'll spend sometime rerouting the cables and see if any improvements...

My usb cable isnt a cheap one,, but it doesnt have the iron ring around it.

here is my setup anyway:

Win7
Reprap Prusa
500W PSU
RAMPS1.3
Pololu drivers
Mechanical endstops
Marlin
slic3r > ponterface

Cheers,
Adrian
Heated bed