Lite-Walkthrough for etching designs using Blender

These are snapshots taken while working on my Derringer Pistol theatre prop project.
The "Lite" in the title just refers to the way I'm just going to explain what's going on in each snapshot, rather than an in-depth walkthrough.

Sides of the barrel selected before removal.
As mentioned in a previous post; Due to myself adding the etching text to the top of the barrel, this prevents me from just doing a straight forward mirror of the barrel and working on one side only.
Here I have selected the middle portion of the barrel, ready to separate out as its own mesh.
From there I delete one side and then use a mirror modifier while I work on adding the etching.

Outing the etching on the photo.
With Blender I can set one of the orientations (front/side/top) to have a background photo. In this case it's one of the side of the barrel showing the 'arrow' etching. The picture to the right shows the tail feathers and my usual method of building up the shape.
Essentially I just select a vertex and then extrude a line from it. Tracing my way around the whole of the etching. I also fill in with triangles as I go along, so my eyes don't get lost as I work.

Angled view of etch object in progress.
In order for the shape to take into account the curvature of the barrel I use a 'shrinkwrap' modifier. For which I then turn on the option that the vertices are effected live while I work on them. It does have the side-effect that the vertex I'm dragging around can jump about a bit, but if the mesh you wrapping onto is fine enough it shouldn't be too much of a nuisance.

The completed arrow shape, with modifiers applied.
Applied modifiers to arrow shape.
Above is the completed arrow shape with the Shrinkwrap and Solidify modifiers (see right) applied.
From here I play about with the Shrinkwrap's 'Offset' and Solidify's 'Thickness' parameters to get the cut into the barrel just right.
I don't want to cut too deep, as I'll go right through the barrel. And not to shallow either, otherwise it won't be visible on the finished print.

In the end I think I went with a thickness of 0.3mm and an offset of 0.01.
Boolean modifier applied to barrel, with arrow shape hidden.

It's not too easy to see, but on the left are my first checks with the Boolean modifier (set to 'difference') to subtract the arrow shape from the barrel.
From here I adjusted the modifier settings some more. Making use of  wireframe mode (keypress Z) to check how deep the etch actually is.

Cleaning up the mesh and preparing for printing.
After applying all the modifiers I've now got a mirrored pair of barrel sides.
The boolean modifier always leaves a mess of half-cut lines, so that needs to be cleaned up before rejoining the sides to the original barrel mesh.
Leaving the mirror modifier till last before rejoining it to the barrel will save you the effort of cleaning up twice.
The snapshot on the right shows the results of running one of the 3D print tools that highlights faces that overhang.
I did start to angle some of them, but gave up in the end. As the final scale is tiny and the printer should be able to just do floating loops.

A reasonable test print

And here we have the first test print. The arrow came out okay. (The top etching did too, but I need to get the lighting right to read it.)

This is the end of the walk-through for now. I hope it can provide everyone with some inspiration for things to try.

If anything doesn't make sense or could be clearer, feel free to leave a comment and I'll make a mention in any edits I make.

Thanks for reading :)


Popular Posts