Printing multiple parts

Hi, I am printing multiple parts of a bigger model that I design with Blender. I cut the parts with Blender bisect tool and then create Stl files that I send individually to Cura. Once in Cura I rotate and snap to build plate to optimize my printing. I never change the scaling but In a few occasions I end up with printed parts that do not fit the others and not by a small margin. Does any one know a way to keep the size while rotating the object?

Can you be more specific when you say “do not fit”? Are these parts that are meant to snap together/there are keys to bring them into alignment?

Have you tried printing the pieces individually to see how they fit together?

I suspect that they’re are not scaling, just that the keying requires a higher resolution than the tolerance of your printer.

no they are simple geometric parts. They don’t snap together and there is no key to align them. I usually just align them manually and glue them and they fit within a couple of mm.
Here the problem is that they seem to print at a different scale.
I see it on the Cura build space, let’s say when I load my model it displays a size of 173.7 x 36.4 x 147.9. at the bottom left corner of my screen. When I start rotating it, the size changes at the bottom of the screen. Even if I don’t rotate it and just use the select face to align to build plate I get a new size of 179.9 x 76.3 x 100.8. What am I not getting?

That’s quite a difference as well as a significant distortion in the differences between the dimensions. Can you post screenshots of what you are seeing? I would think the (more than) doubling of the Y dimension should be pretty obvious.

I’ve never experienced anything like this when I use Cura. By the way, which version of Cura are you using?

You might try Prusaslicer. It has a cut function built in. You could export the part cut it on prusa slicer and keep both halves. conversely cut at a specific point keep and print one half then cut agaon at the same point and keep and print the other.

This eliminates software issues with cura and meshmixer.

Here I was just using the function « select face to align to the build plate

Thank you for the screen shots - they really convey what you are doing.

When I look at the rotations you are putting the irregular object through I am not surprised that the dimensions that Cura is presenting have such radical changes as each dimension has a different face.

Personally, I don’t think that you’re seeing an actual change in the dimensions of your object, but I think you’re going to have to print out a couple or three to verify this. I suggest you print with minimum infill (is 10% possible?) and the thinnest walls that you can select. You will have to use supports for some of these rotations.

Good luck!