S3 Auto Calibration problem ?

[gcarlier 1]

Hello,

 

I'm new here, happy owner of an S3 since yesterday. I experience a problem, a beginner one I presume, but I have problems when starting new prints, as the levelling auto calibration seems not to be ok, maybe ? As shown on picture, some parts on base are not printed. Do I have to calibrate manually in this case. Or do I have an other problem ?

Thanks very much

 

Guillaume

[gr5 2,210]

It looks like your glass is not flat.  Ultimaker uses tempered glass and the process of how it is made tends to give you glass that is not as flat as would be nice.  It would be nice if the glass was flat within 0.05mm but that's hard to do.  It looks like your glass is out by about 0.1mm (high in the thin areas).  The most common error for tempered glass is "high in the middle".  Kind of like a mountain.  Or sometimes a ridge. However:

 

1) This looks fine - if you had let the part keep going you would have gotten a fine looking print (pretty sure) and the bottom would have been flat within about 0.1mm (pretty sure).  Which is quite flat.  The downside is that your part will stick LIKE CRAZY in those areas where it's so thin on that bottom layer.  Extra squish means it will stick badly to the glass and you may have a little extra trouble getting it off the bed on that side of the print.  But probably not enough to be a problem.

2) Yes the "active leveling" is supposed to do multiple point leveling (I thought?) but I guess not quite enough points.

 

I would check with a metal straight edge to see how flat your glass actually is (it's possible something under the glass - say a grain of sand is bending it up in that spot.  It's easy to bend the glass by a few tenths of a millimeter.

 

If the glass seems perfectly flat (straight edge doesn't rock) then maybe you are right and it is the active leveling.

 

Active leveling works better if the spring in the bed is weaker than the spring in the core so you could loosen the 3 leveling screws a lot which will reduce that spring force and might make the active leveling work better.

 

If I'm right and it's the glass you could ask your reseller for a replacement.  Most likely you can get a free one if you can convince them it's the glass. But I think this piece of glass, although it may be worse than average, it still looks like it's within acceptable tolerance.

[gcarlier 1]

Hello,

 

Thanks very much for detailed explanation. Indeed my glass is not so flat after check... I try to play with screws, and will see if it's better, and trying to have another glass.

 

Thanks again

 

Guillaume