Creating a 3d object from flat material is a great way to bend your imagination . In this project the wood bowl was designed quickly in Aspire 11 and cut from 3mm plywood on my 15W laser.
To create this bowl, I needed a pattern that could be scaled down repeatedly without losing details. My concern was that the inner most copies of the pattern would lose the shape. This meant I needed highly accentuated curves and could then repeatedly copy and scale them down from the outside in. Here is the design in Aspire:
If you examine the image on top of the final product, you will notice that each layer is rotate slightly, leaning on the layer below. This is the reason that the sharp edge triangle extends a little below the bottom of the round curve. After copying the outer shape down to the middle, I ended up with the following:
See how the inner most copy is just a jagged circle? Ok - that should take more than 30 minutes, including experimentation with the pattern...Now it was time to cut out the pattern. Notice that this is a super simple design to produce. Once you cut out all the lines, each pair of patterns essentially defines a thin part.
i am using a cool 15w laser of Opt Lasers a company based out of Poland with great support and aftermarket comparability with most popular CNC machines. I have mine installed on my Shapeoko 3 XL. I find it challenging to find the right settings (feed, speed and focal point) because every material and every application (cutting vs engraving) requires a different approach. In this case I wanted to minimize ash/burn marks and cut cleanly through the 3mm plywood.
after multiple tests I was finally ready to cut my parts and here is the process:
as you can see there is considerable yellowing from the smoke generated by the 4 passes by the laser. Later on I learned a few tricks to reduce this: either by covering the wood with a mask such as Ora mask Or blue tape or coating the plywood with a diluted mixture of water and borax. A few coats of shellac work as well and turning on your air assist is the most critical thing you can do. Results of each of the above will vary so you need to find what works best for you: no two pieces of plywood are the same - different species, various adhesives used in the layers and the number of layers - all impact the outcomes of your lasering experience.
After glue-up I must say I am pleased with the results!