X calibration messes up part way through large print - shifted layers
I hope someone can help me. I've been trying for days to fix this problem and wasted a LOT of filament doing so without success.
I'm trying to print a rather large object which will take about 1day 10 hrs to print. I get through about 5 hours perfectly and at approximately 1.5 cm high, the subsequent layers are all shifted left by about 2cm.
I've searched and made sure the X axis belts are the correct tension, the stepper motor gets enough cooling, I've tried two different slicers (Prusa Slic3r and Ultimaker Cura), printing via SD card and USB with Pronterface.
When I last noticed the x layer shifted left I paused the print in Pronterface and sent a command to send the extruder all the way to the right and it went only 3/4 of the way. I sent a command to send the extruder all the way to the left and it kept hitting the stop. This shows me there's nothing impeding the range of X movement but somehow the printer's X calibration has shifted.
Does anyone know why this is happening?
Re: X calibration messes up part way through large print - shifted layers
This will happen if the printer skips steps or the belt slips. My primary suspicion (picture of the failed print, please?) is that it is warping, lifting from the bed, and catching the print head.
Re: X calibration messes up part way through large print - shifted layers
This picture shows how the print shifted about 0.5cm halfway up then I continued printing. At the top you can see everything was shifted left about 2cm. (Sliced in in Slic3r)
I modified the model a bit and reprinted (Sliced in Cura). It was going well for about 1cm then the whole layer shifted left 1cm.
This is what it should look like:
Re: X calibration messes up part way through large print - shifted layers
Loose belt, pulley, or cables snagging. Also might be bearing related. How easily does the X-Axis slide side to side when powered off? If you feel ANY grabbing, you should pull things apart to find what is sticking. Some people have reported if they loosen the screws clamping the X-Axis housing over the bearings allows the extruder to move freely.
It is difficult to see, but it also looks like the part might be warping - popping up and loose from the bed in places. If a corner lifts this way, it allows the nozzle to catch as it passes by.
And last - it looks like the model has multiple shells and some slicing issues. Isn't the middle supposed to be hollow?