3D Balsa Models

One of the more involved projects with your K6 laser engraver is cutting out and building 3D models. This article describes my process for creating the model shown here, which is my employer's company logo made into a windmill.

The material used is 1mm balsa wood, bought from Etsy. It's quite delicate, and you could possibly cut through 2mm balsa with an extra pass or 2.

The design

This article is not designed to teach you how to use your graphics software. At a high level, the design process involved:

• 
  Importing the logo in EPS format. This is a scalable vector format which allowed me to set it to the correct size, and colour it all black to ensure the engraving software read it correctly.
  
  
  
  
  
• 
  The stand pieces were designed as vector graphics again. Using bezier nodes, a nice curved contour could be produced
  and sets the final design apart from something that could have been cut by hand.
  
  The holes for the spindle were created as 1mm circles.
  
  The slots are exactly 1mm, the same thickness as the balsa. I extended the length from the required 10mm to 11mm, to ensure the base would be perfectly flat with a little room for adjustment.
  
  
  
• All images were exported as jpg files at 100% quality. Anything less than 100% could produce aberrations around the edges which will result in less defined cutting.

The cut

The pieces were cut as two engravings. The logo is 75mm square, the maximum square dimensions of the engraver. The stand is 80mm high, rotated 90 degrees to take advantage of the 80mm engraving width.

Cutting is done with Panda 3. The only relevant settings are:

• Cutting power: 80%
• Cutting Depth: 80%

I reached these settings after some experimentation, which included setting the balsa alight when I repeated the cut 3 times! The settings above give you a 95% cut, requiring you to carefully push the pieces out afterwards.

In the image, the blades at the top were cut twice and this resulted in much blacker edges. The base was cut just once, giving the edges a much nicer dark brown edge.

Assembly

To assemble the blades on the centre circle, I printed a template on paper, aligned the pieces, and glued them together. The template is mirrored as it is being glued from the back.

The base is simply slotted together, no glue required.

Finally, the blades are attached to the base using a picture hook tack, pushed tightly through the engraved hole, snipped to length and completed with a dab of plastic glue.

What is not visible from the images is a couple of additional balsa washers which I cut with the engraver, to make a more robust spindle.

And here is the final product, a laser-cut 3D balsa wood model!