Blender project: U-Boat stand

An easy way to make stands for things

This is a quick guide for Blender beginners like me. I feel faintly ridiculous typing this up when there are Blender experts doing complex, incredible things, but one has to start somewhere, yes? ๐Ÿ™‚

A few days ago I finished printing Skimbal‘s giant Bathtub U-Boat on my MakerBot. It took about 35 hours, so once it was done I definitely wanted to display it on the shelf. One problem: the final product wasn’t stable enough to stand on its own without falling over. As you’ll see, this is a very easy problem to fix.

The original source file that has the U-Boat’s pieces assembled and aligned is in Sketchup format, so it needs to be converted into something that Blender understands. First, open the file in Sketchup and use the Select tool to shift-click the middle three pieces of the white U-Boat.

Then, go to File -> Export -> 3D Model, set the filetype to .obj, and change the export options as pictured: (click for large)

Now open Blender and use File -> Import -> Wavefront on the exported file. You’ll have to scroll way out in order to see the pieces. If only the middle piece is selected, hold shift and right-click the two end pieces to add them to the selection.

With the three pieces selected, use the Object Tools menu on the left to first Join them, then click Origin and Set Origin to Geometry.

Next use Add -> Mesh -> Cube to create a box, then press the “s” key to grow it with the mouse, then drag the box into position like this:

If the Properties menu (with the heading “Transform”) isn’t visible, press the “n” key to display it. From here you can lock the X and Y Scale axes and press “s” again to make the box wider without making it taller.

With the first stand in place, lock the Y and Z Location axes and press shift-d to create a duplicate. Drag the duplicate to the other end of the model.

For each of the stand pieces, use the Modifiers section of node editor panel on the right side of the screen (click the wrench icon) to add a Boolean modifier:

Set the modifer options to Difference the U-Boat object (named “Mesh”) and click Apply:

Almost done. That removed the portions of the stand pieces that intersected the U-Boat – now we just need to select and delete the junk portions that are left. Use the Outliner panel to hide the U-Boat mesh by clicking the eyeball icon on the row with its name. Now select one of the stand pieces, press tab to switch to edit mode, press “b” to select a portion of the leftover bit, then ctrl+l to select the rest of it, then press your delete key and hit enter. You should now have only the actual part to be printed left:

Press tab to return to object mode, then File -> Export -> Stl to save out the final file for 3D printing. Repeat the select and delete steps for the other stand piece and export that one, too.

Now you’ve got perfect-fitting stand pieces! If you need something clarified (or have a better way to do all this!), let me know in the comments. The stand pieces that I made on Tuesday can be downloaded here:

Derek Quenneville is a 3D printing evangelist who posts weekly on the Ponoko blog. Follow him on Twitter @techknight.