Blobs with Updated Firmware / Cura on Ultimaker S5

[DrCeeVee 19]

Hi guys,

 

Just a quick post to report that I'm experiencing blobs on my prints, using the latest firmware on my Ultimaker S5 (version: 5.5.12-20200226-UltiBot), and the latest Cura (version: 4.6.1). The print head just freezes for a few seconds (maybe around 5 seconds), and then resumes movement, but it leaves a nasty blob behind it, as the nozzle keeps extruding molten PLA while the head is frozen. The print is otherwise perfect. See attached image. The blobs may happen a few times, depending on the size of the print, and this results in a perfect print with a few large "pimples" on its outer surface, which I have to shave off using a razor blade. I'm using non-Ultimaker, but high quality PLA, the same that has given me many prints without blobs or any other issues in the past.

 

With the older f/w and/or Cura (can't remember the exact versions), and after printing hundreds of face shields for COVID-19, I never experienced a single blob. During the course of using the S5, I've promptly updated the f/w and Cura whenever I was notified of updates. I started noticing the blobs about a week ago, but I haven't been using the printer much lately, so it could go a bit further back. I'm not sure if the f/w or Cura or something else causes it, but it's definitely there.

 

I'm on Wi-Fi, if that makes any difference. I had to stop a test print I was doing earlier, due to a blob appearing on the outer surface. The attached image is from that print. I'm now repeating the exact same print with the exact same material and settings, but using a USB stick as the source of the data, and have switched off Wi-Fi from the S5 Network options menu. This is to rule out any network issues. Will report back when the test print completes (14 hours to go).

 

Is anyone else out there experiencing similar behaviour? Any info, comments, advice, are greatly appreciated, thanks.

 

Edited May 12, 2020 by DrCeeVee
Formatting improvements.

[DrCeeVee 19]

Update: the test print via USB stick (Wi-Fi disabled in printer settings) came out absolutely perfect, without any blobs or other issues. Based on this, it seems that the Wi-Fi may be causing some random freezes which affect head movement during printing. If any of the Ultimaker mods/staff is reading this, please forward my findings to your engineers, as there may be issues with the S5 Wi-Fi and how it interferes with the printing process (it shouldn't).

 

I will keep using the S5 via USB stick for a while, to have more reliable data on print quality, and will then switch back to Wi-Fi to see if the blobs come back, so as to have a more definite result.

 

Will report here what I find.

 

Edited May 13, 2020 by DrCeeVee
Added photo.