Plate and nozzle forcing against each other after ~10 good prints, leveling does not help (UM2+ Connect)

[utopiah 3]

Hi there,

 

received my UM2+ Connect few days ago. I made a dozen of prints without any problem.

My last few prints failed though. The nozzle carries away the 1st layer or so. I believe the plate is either too high or the nozzle too low. I thought this might be due to me changing the material and moving the printer a bit. I then try to level the plate but somehow now, no matter how I play with the plate screws, the nozzle stay stuck to the plate. I can't push under the calibration card.

 

Any suggestion?

[utopiah 3]

Well.. apparently I still need to learn how to turn screws the right way! I'll blame my excitement 😉

 

Adjusted the plate properly now, starting a new print to test but should be all good. Sorry for the noise!

[utopiah 3]

Didn't seem to help. I'll try to lower the bed a bit more and eventually add glue. Somehow the whole head vibrates during some part of the print. It seems as if it is too close to the bed.

 

Good print (2 days ago) on the left and bad print on the right today, despite extra measures e.g. leveled plate few times, added adhesion as visible behind the bad print, added glue on the plate.

 

I'm now checking the room temperature (to be between 20 and 30 celsius) but somehow I can't imagine that'd be a link to the distance and new noise.

Edited December 28, 2020 by utopiah
add photo with comments

[utopiah 3]

Here is the video. 54sec in we can hear the sound of a vibration that didn't happen for the first 10 successful prints.

Edited December 28, 2020 by utopiah

[utopiah 3]

Could it an unlucky situation where

• 3D model sliced with a certain precision
• printer with its intrinsic mechanisms e.g. belts
• some noise e.g. bits from past prints stuck somehow in e.g the z-axis host
• support as a table

all together enter in resonance of frequency and that just "shakes" the whole setup?

 

If so should I just try with other precision, if not design, if not weight the printer on a different table?

 

What's the process here? It's quite surprising to me that the first 10 prints worked nearly flawlessly then somehow now I'm getting, quite literally, stuck.

[utopiah 3]

Room temperature is 23 degree, build volume 25 degree so I can for now remove that from potential causes.

 

Here is a video of the plate moving where 17sec in we can hear a different sound. I'm wondering if this is preventing the plate from moving just a bit, e.g. 0.1mm, but enough for the nozzle to crush the material against the plate and pull it rather than a clean deposit. If this sounds likely, how can I clean the inside of the white box with "ultimaker" written on it?

[Smithy 1,144]

From your first video, the vibrating noise is coming from the sliced gcode. Check the preview, I am pretty sure the printer don't print a straight line, but many very very small ones which results in this vibration.

 

If you still have adhesion problems, I would say (just from the video) you are a bit too high, the first layer should be squished more into the bed. But if you are happy now, then leave it as is.

 

Regarding your second video with the z axis, I don't see or hear any problem, it is normal. 

 

[utopiah 3]

Thanks Smithy for the feedback. I was worried as I never heard that sound until then and it followed or preceded failed prints. I was indeed wondering if gcode and some bad value, but was worried if it was the source of failure rather the consequence of specific gcode. Thinking back I believe you are right that in no other situation I heard those. This is also why I indeed raised the plate : I thought the nozzle was too low and thus pulling away previous part (hence the title for this post). Maybe it was a combination of all those : tricky gcode, lack of adhesion but also "luck" of having one print work. If nothing looks off to you then I'll just perfect my understand of the machine and the process. Thank you again for those clarifications and being my first help in this forum 🙂

[Smithy 1,144]

No problem, you are welcome!

 

Bed leveling is important, it is easy to do, but also the most complicated thing. You need some iterations to get a feeling what is the right leveling, because leveling with the card or a sheet of paper until you feel some resistance is ok, but how much resistance? That's what I mean with feeling. I level with the card until I think the nozzle would scratch the card, but not so much that I can easily move the card under the nozzle. Hard to explain but try a few heights.

 

Regarding gcode, so very small zig zag moves or similar to that can make the whole printer vibrating. I also thought sometimes my printer has a problem, but actually it was just printing a strange wall. You can try the new Cura beta, which should bring big improvements with such strange paths. Specially with circular objects, it should make better results.

 

And if you have further  questions, just ask in the forum. We are here, 24x7 following the sun and normally we are quick in answering questions. 

 

[utopiah 3]

On 12/28/2020 at 1:07 PM, utopiah said:

the whole head vibrates during some part of the print

 

Well it took me a week to figure it out, or rather to understand what was already said : I tried again the same print but I changed back the quality (layer height) from 0.2mm to 0.1mm. Obviously it takes a lot longer but... the "weird" sound is gone. I imagine the zigzag that the slicer made was correct yet problematic for my context.

Edited January 3, 2021 by utopiah