by TLHarrell » Thu Mar 06, 2014 6:53 pm
It is possible, but there are a couple issues.
First off is the depth control on a laser is not accurate. Depth of cut depends not just on settings, but on the material density (which can vary a lot in the same part), and many other factors. You cannot simply say "I want to engrave each layer 0.003"." It doesn't work that way. The material may behave differently each time it's hit.
Second is the required time for 3D engraving. I've run tests on a sample size of 2"x2" and it took nearly an hour to run 16 passes. I had to cut off the last couple passes too as with the settings I had, it ended up blowing entirely through the material (1/8" MDF at the time).
Unlike cutting in 3D with a milling or engraving bit, where you know the exact location of the end of that tool, laser engraving is frustrating, inaccurate, and time consuming. I recently purchased a small (24"x24"x5") CNC to complement the laser and make up for these types of shortcomings. The laser I use for 2D cutting where I need very fine geometry or tight inside corners, and for engraving/paint removal for my designs on acrylic. The CNC I use for larger parts removal from sheets, stepped or accurate depth cuts in 2 1/2D parts. I very rarely deal with full 3D stuff.
40w Full Spectrum Engineering 5th Gen Hobby 20"x12" w/ Rotary Engraver
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