We have a client who makes complex Jigsaw puzzles, and although our standard large lasers come with a 63.5mm focal length lens (which cut extremely fine lines), this was not good enough for the large scale puzzles they cut. We considered an option of a 50.8mm lens (which has a slightly better performance in terms of finer lines, but the trade-off is that cutting thicker material is difficult), but when we heard that the client would only ever cut 3mm pine MDF, we decided to use an even finer option, a 38mm lens.
So what does this mean – and what is the benefit to the client?
If you refer to my Technical Bulletin #9 , where I discuss the benefits of a longer focal length lens to cut thicker material, you will see that as you lengthen the focal length, the ability to cut thicker material increases, but with a trade-off – the spot size gets bigger, resulting in a wider kerf (or more material burnt away). Conversely, shortening the focal length allows less thick material to be cut, but with the benefit of a much finer kerf, which is perfect for finer, more complex jigsaw puzzles.
So the takeaway is : If you are wanting to cut finer cuts with a maximum of 3mm MDF, consider a 38mm lens.
And don't forget you will need a "flat" nozzle as well.