Build plate issues on S3

[nolank 0]

Hi,

I've a S3 that is giving me build plate issues lately. It fails to auto level returning: "Difference between detected height of both PrintCores exceeds realistic values”.

The build plate will approach the print head and stop some distance away from it (several mm). Occasionally one core will successfully make contact but then the second one will fail to.

Manual levelling and restarting the printer rarely work but repeated attempts to restart the print eventually succeeds. The only other clue to what is going on is a report of a "Unknown build plate" conflict when loading a print from USB.

 

I've factory reset the printer, installed the latest firmware and the latest version of Cura. The only thing I haven't been able to do is connect the printer to our Institution's WiFi so I can sync it directly to Cura due to network restrictions. I don't see any way to change the build plate to anything other than the stock one so I don't know why the printer is reporting a conflict after a full reset. I see similar posts here and all I can see relevant is the proximity sensor as the culprit.

 

Any ideas?

Thanks.

[gr5 2,170]

Thanks for explaining that the nozzle doesn't touch the buildplate in failure mode.  99% of people don't mention this and it's crucial information as there are 2 other failure modes.

 

I believe in the maintenance menu there is a way to test the sensor. It should return a value.  Values at 8 and below are good.  The larger the value the more noise or something is detected?  I'm not sure exactly.  Values around 15 I think cause intermittent failures.

 

Anyway run that test a few times to get a baseline and assuming it's well over 8 try some things and try to get that to a lower value.  Get a baseline with the 3 fans off and again with the front fan on (actually maybe you are forced to have the front on during the test?  not sure).

 

Check the two wires to the sensor.  When you open the front door on the print head the sensor swings down - it's in the base of the print head.  It's basically a flat metal plate and the capacitance is determined by the distance from that plate to the metal plate under the glass bed.

 

Tug very gently on the two wires to see if one pulls free because it's not connected at all or was barely connected.  That was my issue on my printer when it was failing active leveling.

 

Next fan cable.  Try rerouting the front fan wires.  Or unplugging the fan.  Sometimes the solution is to replace the front fan.  If it works fine with the fan off but fails with the fan on then you need to either route the fan cables farther from the sensor cables or you need to get a new fan.

 

I believe the side fans don't matter because I think they are off during leveling.

 

 

[gr5 2,170]

By the way if you have older firmware it doesn't report the number on the screen but you can get it from the log file if you open the file containing "boot0.log" in the filename and search for "noise std".  When I did the test I got a noise value of 2.2.  A friend of mine got a 3.  Again, anything < 8 is pass.

[rsvveen 0]

Dear all,

I was triggered by the fact that you get the 'Unknown build plate' message.

I get this message on a S5 and figured out that I get this message only when using Cura 5.2.1, but not when using Cura 5.1.0.

I tried several settings and designs but the same behavior.

Something in Cura 5.2.1 causing this problem?

[MariMakes 198]

Hey @rsvveen,

It's a harmless and known issue introduced in Cura 5.2.1.
You can read more about it here: 

 

[rsvveen 0]

Dear @MariMakes.

Thanks for the message and info.

Is there a place where known issues and bugs of each Cura version are listed on the Ultimaker website.

Now I notice that this question/problem is mentioned in several posts.

Before posting I checked, but cannot find such a known issues and bugs list for Cura versions.

Thanks for your help.