I feel like I should preface this article with a mention that I had a natural bias towards height tools despite never using a machine with a touch probe. I personally prefer machines without attachments on the cutting heads because they can move faster. Now I have two machines with the two different focusing mechanisms I'm finally able to write this article from a factual viewpoint.
Why the laser needs focusing
The beam that comes out of the end of the laser tube is actually quite wide, my 100W tube can make a spot size 5-10mm across if I shoot it directly at a piece of material. This beam wouldn't be very effective at cutting material so it needs to be focused down to a small spot. This increases the intensity of the beam at that exact location and allows it to vaporise the material as it traces out the shape of your work.
There is a lens in the cutting head of the laser that focuses the wide beam of the laser into a single spot point on the surface of the material. It's …
This is my laser cut cryptex. It features 28 different characters and 9 rings, giving a total possible 10.5 Trillion different combinations. I took a bit of time developing the design so that I could add some nice features. This cryptex file is laid out so that you can have any number of rings in your own design. The best feature is that the codeword is changeable, each locking ring has an outer letter ring that can be placed in any one of the 28 different positions. Once the rings are back in place the ring locking bars can added and they prevent the rings from being modified until the box is open again. It's a bit hard to explain so I made a video showing how it all work (svg here)
It took a long time to assemble this so I lived with my initial design choices but if I were to remake it I would adjust the file to make the ring locking bars out of 6mm ply and maybe put some blind holes onto the code rings to prevent the code being brute forced.
I had a local craft fair this weekend, I wanted to add a few extra/new items to my range so that my stall would be very different from last time. I've seen lots of variations on this wine box so I thought I would make my own version. The living hinges at the top allow the sides to be pulled close and the lid closed, it also a great place to put a handle. The fretwork patterns down the sides make them unique to me as well as the custom labels attached to the side. (svg here)
I didn't sell very many and I'm not sure any were going to be used as wine bottle boxes, one lady wanted to put plants in it and another was going to put fairy lights in hers. Neither wanted the the custom labels so I'm pleased they were only held on with blue tak. It's definitely given me food for thought with the next craft faire looming.