Prints failing with random offset x/y
New Prusa-built Coreone in November, worked out of the box without problem, upgraded immediately with latest firmware. Since then run about 25 long (time-wise) prints without trouble. Then, a few days ago, a print failed with massive x/y offsets (2-4 mm) and even a crash into the print sheet. No warnings, just failure. Looked for problems with loose belts, etc., nothing to be found. Attempted homing calibration whihch failed three times. Calibrated axes independently and eventually got homing cal to work. Attempted a print but failed on layer 3 or 4 in the same way. This time, I did notice tht the move of the printhead around the print (which is only 50mm across) when not extruding (i.e. moving from one xy to another co-ord to start another extrusion track) was very rapid and emitted a sharp 'bang' type of noise when moving. Now, I have 2 CoreOne machines and the other one with the same firmware does not behave like this when printing the same item.
Has anyone had a similar experience? I did contact Prusa support sending pics of my problem but that was not a good use of my time, they asked me for pictures of the print head, and eventually told me that the hotend was loose, which it certainly was not and is not. I'm getting desperate now, not knowing where to look or what to do....
RE: Prints failing with random offset x/y
... was very rapid and emitted a sharp 'bang' type of noise when moving.
Have you (accidentally) enabled the "don't cross perimeters" option? There is a known firmware issue where the printer tries to accelerate more rapidly than possible with the motor's torque, causing the steppers to slip. Symptoms would fit. Make sure the option is not enabled.
RE:
Thanks mnentwig, I'll check that. But...
In desperation I took it upon myself to check the pulley on the Y drive. It was loose. So I checked the X drive as well - it must have been tightened by a 6 month old baby - it too was nearly loose. Also - shockingly for a Prusa-built machine - there is only ONE bolt NOT FOUR holding the motors in place. On my other CoreOne, all four are there on each motor. More - the one bolt holding each motor was loose! WTF? I paid £1200 for this machine, and it wasn't properly built. Prusa - what are you playing at?? What else is wrong with my machine now? How will I know? When will I find the next build fault? This is unbelievable and has cost me hours. Yet more - when I asked for support, I was told that my hotend was loose - shouldn't the first suggestion be "check the motor pulleys"?? My confidence in the product has been rocked.
RE: Prints failing with random offset x/y
Any chance you have the prints to check the angle? Knowing if it's 45/90 degrees or an odd angle would drastically reduce the number of things we would be looking at