S5 Hotend - Z Height Too Low - AA 0.8

[cmuhleman 1]

Hi All,

 

Just started working with a new print core, the AA 0.8, and I'll have an occasional issue where the Z height isn't calibrated correctly and the hot end will scrape across the face of the print bed after calibration and while the print is starting, plugging the filament into the core and scraping up the bed.

 

This happens every time I attempt to do a dual extrusion print with with the AA 0.8 print core and only sometimes when printing with just the AA 0.8 core. I can't quite tell the rhyme or reason to what causes it. One file printed just fine, but when I reoriented the print by 90 degrees, it scraped across the bed.

 

I'll attached a picture, just incase that's got any clues on it, as well as the gcode.

 

Running Cura 5.6.0 and firmware 8.3.1.

 

Any advice would be appreciated. Thanks!

UMS5_Corrugated.ufp

[gr5 2,228]

So it sound like sometimes the active leveling is off.  I don't think the 90 degrees thing had anything to do with it.  But it sounds intermittent which makes it harder to debug.

 

Start by going to maintenance and testing the leveling sensor.  It's a very quick test.  It gives you some numbers I think (different versions of the firmware show you the numbers differently and I lose track).  Lower numbers are better.  8 I think is the passing threshold.  larger numbers means there is more noise confusing the sensor.

 

The most common thing messing up the leveling sensor is the front fan.  It can both be the cause of electronic noise or the fan coil can act as an antenna to pull in radio noise from around you.  Make sure electronics like computers, phones, toasters, etc are at least a meter from the printer.  Especially motors like refrigerators and vacuum cleaners.  Keep those 2 meters away, lol.

 

Let us know the returned value when you do the sensor test.

[cmuhleman 1]

Ah, I see. So it does a separate active levering for each printcore, and the second one, for whatever reason, seems to be failing. That makes sense. I'll run that test and report back.

 

Thanks!

[cmuhleman 1]

Reading came back consistently low, from 1.67 to 2.05. There is a regular 2d printer sitting next to it, but not in operation during calibration or any 3d printing.

 

More importantly, I can't seem to replicate the issue anymore so, this may be unnecessary! I'll keep an eye on it and post again if that issue returns.

 

Thanks for your help, gr5!