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Ultimaker / Cura

3D printer / slicing GUI built on top of the Uranium framework
GNU Lesser General Public License v3.0
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Thin support towers - Prime tower is missing layers, printing it mid-air #13437

Open themobydisk opened 2 years ago

themobydisk commented 2 years ago

Application Version

5.1.1

Platform

Windows 10

Printer

Ultimaker S3

Reproduction steps

  1. Open CURA with defaults for an Ultimaker S3
  2. Extruder 1 = PVA, Extruder 2 = PLA ^^ This only happens if you set extruder 1 to PVA. If you select PLA it behaves differently.
  3. Import an STL that needs support sitting on the model, not the platform. See attached example.
  4. Check "Support"
  5. Check "Enable Prime Tower"
  6. Slice

Actual results

The resulting prime tower does not work: the prime tower only prints the PVA on the layers that need support. So the first layer that needs PVA, the prime tower attempts to print the PVA floating in mid-air, which does not stick to the tower. The nozzle then has a long string of PVA hanging when it goes to print the PVA.

Expected results

I wanted the result produced by CURA 4.13.0. The prime tower primes both nozzles, starting from the bottom, regardless of which layer is the first layer to require support. The prime tower stops priming the PVA at the last layer the PVA is required.

Checklist of files to include

Additional information & file uploads

Does not happen in CURA 4.13.0 (I have not tried other versions) Does not happen with PLA as the support material Does still happen if you swap the PVA to extruder 2. CURA BUG REPORT - Prime tower is missing layers.zip

MariMakes commented 2 years ago

Hey @themobydisk,

Thanks for your report. 👍 Sorry, it took us a while to get back to you 😞

What you are seeing is by design, the inside of the prime tower doesn't need to fill up to function as a place to prime. The inside ring is only printed if it is actually being used for printing.

What I do notice that your model is heavily impacted by the support changes introduced in Cura 5.1. Suggestions on getting more sturdy and functional support can be found here: https://support.ultimaker.com/hc/en-us/articles/6103470096028-Why-are-thin-support-structures-missing-from-Ultimaker-Cura-

I did notice that if you change the support overhang angle to 70 degrees your model has a higher chance to succeed printing: image

We've added a ticket to the backlog with the intent to improve this support behavior. For internal reference CURA-9658

Thanks for the report! 👍