I am using an industrial grade 3d printer, it has a voxel acuracy of 23 micron. Although i cannot show my model here, its about 1000 times larger then the default suzan, as i export it later to STL, and as blender isnt aware that the default stl scale for 3d printers is mm. (the STL format itself has no size, but scaling it 1000 times works well)

Anyway with those large objects in reality just a few centimeters tall, i kinda get random warning of thin faces.

Is this normal, or should it reported as a bug ?.

  • $\begingroup$ It's normal from what I have experienced. $\endgroup$
    – Yohello 1
    Commented Nov 12, 2019 at 16:32

2 Answers 2


There are two ways for you to handle this.

The first is through the length unit settings in the scene tab of the properties panel (bottom right in the image below). You can simply set the scene units to millimeters instead of meters (which is the default), and the 3D printing toolbox tests will update accordingly.

The other one is by changing the thickness threshold in the 3D printing toolbox thickness tests to whichever is the limit you're aiming for (which corresponds to your 3D printing tools and materials).

enter image description here


The actual thickness of the model should be created in the 3d modeling program itself. If you want to know how thick the model is after you export it, you may have to use a secondary program like Meshmixer. That program can tell you how thick certain objects are by millimeters. I learned that lesson when I was making my 3d printed helmet for the first time and when I was still learning the ropes, I learned that in order to get a more sturdier build, I had to increase the thickness of the mesh in Blender and examine it in Meshmixer before I send it out for print.

  • $\begingroup$ I understand what you mean though even with that knowledge it apears quite random those thickness warnings, ea some face got it, while the opposite side of a mirrored shape doesnt get a warning, i see it on the thickest parts and some of the thinnest parts dont have it. There are no double vertexes that might explain it, ithe results of the addon just seam wrong to me $\endgroup$
    – Peter
    Commented Nov 12, 2019 at 14:38
  • $\begingroup$ If the model was created using a Mirror modifier, you may have to cut in half and create it again. Just in case. $\endgroup$
    – Xero
    Commented Nov 12, 2019 at 14:41

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .