[UM3] Help with calibration

[Nikcho 0]

Hi fellas,

We've just bought new UM3 . So far I've followed the "Get Started" procedure and finished it successfully.

Next step that I did was to use the calibration card for the "Z and XY offset calibration". So far so good. The problem that I have is with "XY offset calibration"! For some reason print core 2 (loaded with type BB) is doing very poor job. I've uploaded photo from the glass plate, after the calibration on my google drive - https://drive.google.com/file/d/0B7tmejZzptFjY25TZUs1ZjRNdFU/view

Can someone guide me what is going on?

Edited April 24, 2017 by Guest

[gr5 2,224]

PVA is trickier to work with than PLA. The basic problem here is that the second nozzle is too far from the bed. Either rerun the calibration procedure and do it manually and make sure the two nozzle are exactly the same height.

Or maybe they are the same height and you just don't notice it so much with the PLA. So option 2 is to raise the bed just a little bit by turning the 3 screws counter clockwise about a half turn to get the filaments (both pla and pva) to squish a little better into the glass. They should be flattened like a pancake.

Squish is the main problem but it also helps to put down a layer of PVA glue. Use the supplied glue stick and put down just a small amount (back and forth maybe 4 times with the stick with most glass getting nothing) then spread it around with a wet paper tissue. This wet tissue will help make it very very thin and also remove some pva which is good. Heat the bed to 60C until it's dry (just a few minutes).

[Nikcho 0]

Hi gr5,

Thanks for the answer!

 

Either rerun the calibration procedure and do it manually and make sure the two nozzle are exactly the same height.

So far I've rerun the calibration procedure several times with no success. I do not understand why when I use the calibration card, I get the needed resistance when sliding under the BB print core but when I start the calibration procedure it just does not apply the material on the glass. At the end It seems that the BB core is not close enough to the glass.

 

So option 2 is to raise the bed just a little bit by turning the 3 screws counter clockwise about a half turn to get the filaments (both pla and pva) to squish a little better into the glass.

At which point should I try this? Or just raise the platform and do it?

 

Use the supplied glue stick and put down just a small amount (back and forth maybe 4 times with the stick with most glass getting nothing) then spread it around with a wet paper tissue.

Is there some tutorial/video for applying the glue?

[gr5 2,224]

1) Mainly I disagree with the calibration card. I recommend using no card and having the nozzle touch the glass barely. If you experiment you can do this consistently even more accurately than the card. This results in a MORE SQUISHED bottom layer.

2) Yes. Just do it. Anytime. Power on. Power off. while printing. Anytime. No need to calibrate anymore as the bed is probably quite level - just a little too far from the nozzle. PLA is more agreeable than PVA. You are probably not squishing the PLA very well either but because it has a little more tolerance you don't notice.

3) Yes! This tutorial shows all these things - how to just adjust the 3 screws. How I do the "no card" calibration. How to apply glue 3 different (and all excellent) ways. It's long but full of great information!

[tomnagel 126]

* XY calibration was done in the factory for the AA/BB combination (only for the AA core that was in the printhead in slot 1 when you opened the box). You shouldn't have to rerun it. Does your printer tell you to run the XY calibration?

* Is there enough material flow? Is the nozzle indeed too high when printing?

* do you have Active Leveling turned on? (should be turned on by default). That should determine the print height accurately

[Nikcho 0]

Thanks again gr5!

XY calibration was done in the factory for the AA/BB combination (only for the AA core that was in the printhead in slot 1 when you opened the box). You shouldn't have to rerun it. Does your printer tell you to run the XY calibration?

No, it does not require me to run the XY calibration. The problem that I have is with printhead in slot 2 - Currently BB 0.4

Is there enough material flow? Is the nozzle indeed too high when printing?

Yes, there is material. I think that the nozzle is too high, but the on the recalibration procedures I set the printhead 2 to be close to the glass.

do you have Active Leveling turned on? (should be turned on by default). That should determine the print height accurately

Yes Active Leveling is turned on

[peteruithoven 4]

You might find this topic interesting:

[gr5 edit - fixed link]

 

 

[Welveryn 2]

It seems really difficult to peform a XY calibration. Actually I tried to, but I had a big bug on the BB print. The extruder always trying to push in and push out the filament (is it a normal behavior?).

 

Then I have a really bad result on the glass, which is not enough relevant to perform the calibration. I guess...

Can you help me to understand?

[gr5 2,224]

1) @Welverynyou are chaning the subject.  Please post a new topic.

2) Did you install 5.2 upgrade?  There is a known bug in 5.2 (latest firmware as of today, april 25, 2019) where XY Calibration does not work anymore on UM3 and S5 with latest upgrade.  The workaround is to manually feed the second extruder when it starts drawing the lines with the second core.

 

[Smil 0]

I have the same or similar problem - except I tried both PVA and TPU (both original UM w NFC and freshly opened).
Newly bought UM3. Fresh updated firmware.

After leveling the buildplate as pr. instruction, I can't get it to print. It seems as if the leveling is not included when doing xy-calibration - as normal prints adheres just fine. For the most part the PLA works ok, but seems to underextrude or not get close enough (I'm unexperienced, sorry) and for every small bit it splashes out (not adhering) it seems to retract the fillament way too much. 

 

 

[gr5 2,224]

I think I just said this in my post above.  THERE IS A BUG IN 5.2 (the latest firmware as of today April 27 2019).  So either don't upgrade your firmware or if you already upgraded you have to manually push the filament through the second extruder when doing XY calibration.  With your hands.  Or don't do XY Calibration.  Or just enter 0 and 0 for X and Y calibration values as that's often close enough.

[Smil 0]

Sorry mis-read your first post.
Do we know if any update is due soon?