"Align face to build plate" does not work for grouped or merged models

[evilC]

Application Version

5.2.1

Platform

Windows 10

Printer

Snapmaker J1

Reproduction steps

1. Import attached 3MF model which comprises of two parts
2. Merge or Group the two parts
3. Select the merged / grouped model
4. Select Rotate
5. Click Select face to align to the build plate
6. Click the front face with the text on it

Actual results

Model is de-selected and does not change orientation

Expected results

Model should be rotated so that the selected face touches the build plate

Checklist of files to include

• Log file
• Project file

Additional information & file uploads

cura.log
Riot shield 03.zip

[MariMakes]

Hey @evilC,

Thanks for your report 👍
What an interesting case 🤔

It seems that aligning the groups also doesn't work in Cura 4.13, so it hasn't worked in quite a while.
I'll bring it up to the team to see what they can do to improve it. But I expect that if it's not a quick fix that it will not get a high priority to implement.

Fingers crossed 🤞

[evilC]

@MariMakes
This is quite a big issue for owners of IDEX printers.
Presently, I see no way to accurately align a multi-part print AND orientate it to any face.
If, for example, with the attached file, you center both of the models (Without grouping / merging), and use the Select face to align to the build plate option, it DOES NOT align them as they were originally aligned. It is close, but not perfect.
The only way as far as I know is to manually tweak the X/Y position and this takes a long time.

For example, if I do not group the two parts of the model, align them to the face I want to print on, and center both models, this is what I get: (Notice how the text is not perfectly aligned - the blue text is too low down)

Here, I have moved one of the models by 0.1mm on the build plate - note how it is now properly aligned:

Now as far as I am aware, if you have multiple models in a 3MF file, they all share the same coordinate space, so there should be zero reason why it cannot work it out. The problem is clearly not solely limited to the align to face feature

Here is a version of the model that I pre-orientated within my 3D modelling software so that the face I want to print on is already aligned to the build plate:
Riot shield 03 orientated.zip
However, when you import this model and center both of the models, the text is STILL not aligned correctly.
If you select both models and Group them, it aligns them incorrectly.
If you select both models and Merge them, it rotates them by 90 degrees, but they are aligned correctly

[MariMakes]

Hey @evilC,

I brought your issue up to the team. Your extra notes were super helpful 🙏

We've added a ticket to the backlog with the intent to improve this.
For internal reference CURA-10149

Thanks for the report! 👍