# Making edges "square" for 3D printing

I am 3D printing models that I have created in Blender to an exact scale (1:30). Quite often, the edges I have created in Blender are not quite square (not that I would notice in the Blender world), with the result that the 3D printer performs a few "rasters" rather than one continuous horizontal surface. You can see that it has worked out OK in the first image below (printed with a 0.15 mm layer height)) but when I increase the resolution of the print to a 0.10 mm and then a 0.05 mm layer height the problem appears.

These can have quite a significant adverse effect at my scale, so I was wondering/hoping if Blender offers a mechanism to "squarize" selected edges?

• Could you clarify what mesh do you work in Blender with and what areas there possibly cause problems? I don't think I understand what is "squarize edges" since edge is a line between two vertices, it's always straight. Likely you mean something else. Nov 12, 2018 at 1:06
• This really sounds like a problem of the printing process, not something that can be fixed in Blender. Nov 12, 2018 at 6:53

Sounds like you want to keep your horizontal/vertical edges perfectly horizontal or vertical? If so you can use Blender's snapping tools to make sure that vertices line up perfectly. If you don't want to snap individual vertices, you can use the 'Mesh Edit Tools 2' add-on that comes with Blender...no need to download or purchase or anything; it should be there already:

Under 'Vertex' select the dropdown and choose 'Custom Coordinates':

Then select the vertices you want to align, like this exaggerated example:

Choose 'Align Coordinates' and type in the value to align to. In my example, it's just z = 1.0:

Click 'Ok', and boom, all of the vertices are now EXACTLY at z = 1.0:

Obviously you'll need to figure out the values to square to, but this should give you perfectly straight and square prints if you take the time to align the vertices on your edges.

• Ooo, that sounds perfect, let me give it a try...
– Rob
Nov 12, 2018 at 20:52