It can cut wood up to a quarter of an inch thick in one pass.
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Cmreeder: I started with an Apple IIe and was the only guy at my grad school with a personal computer - a Mac 512. I even possess a Microsoft Excel v1.00 floppy disk. I lived the revolution and they continue today in the world, but Apple seems a lot like it was before Steve Jobs returned as CEO - defocused and lacking exacting standards. When I was at AOL, I ran broadband product management and had to have both a Mac and a Windows box to test the service. The both had their crashes and hassles and each their particular UX strengths, but neither trounced the other. The BS happens on both sides. My fiancé was just mentioning that she hates to update her iPhone because they change the interface and leave her trying to figure it out again.
Back to exacting standards… It took guts for Steve to hold a release until the product was absolutely right. He would reduce the feature set down to just the most important things and then make those spectacular. I see a parallel with what @Dan is trying to do. So I respect that. Another thing that Steve did is that he would get his team to achieve the seemingly impossible in his “reality distortion field”. I’d like to see that with the GF schedule. 
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The only limit to how deep you can engrave is the focus range. When doing a through cut the depth is limited by the hourglass shape of the beam. I.e. if you try to focus at the bottom of the cut then the wider part of the beam hits the sides at the top of the cut. To go deeper you would need to widen out the top of the cut and make a V shaped trench.
There will be a limit to how steep you can make deep edges when engraving.
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Thank you, upon seeing this piece, I was hoping that someone would explain how it was a 1/2 inch thick. Do we know what the focus range is. I would assume a limit on the Z axis of movement for the laser head would also affect the focus depth limit?
I know very few people have a GF yet, but how thick of a piece should we realistically expect to be able to cut?
This is welcome news for me as I thought we were limited to 1/4" thick!
edz
The focal range is .5 inches. Unless they release another head with a different focal range (which they most possibly could!), .5 will probably be close to the limit at which you can cleanly cut through something.
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The Glowforge doesn’t have a moving Z axis. It just has a variable focus lens. That is probably achieved by moving the lens 1/2" up and down within the head but I wouldn’t class that as a Z axis.
I think thin cuts will be limited to about 1/4" unless you flip the material and cut from both sides or you cut a sloping V trench by using variable focus engrave to give 1/2".
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Apple vs Windows is religion 
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I almost made the same comment :v
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Still trying to understand how this works. If a sloping V trench is cut, the laser refocused and another cut done on a second pass, would the resulting cut be a straight cut?
The alternative mentioned is to flip and do another 1/4" cut. How would the piece be aligned in such a precise manner?
Thanks
edz
I think the alignment for a flip cut is something they are still working on. It has been mentioned as a feature they are planning on, but I don’t think they’ve been able to perfect it yet, at least there hasn’t been any mention by anyone in the know.
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One of the things I wish I knew (sorta) is what “still working on it” means in all these contexts. In some of them, it may mean “we’re coding the basics”, in others “we’ve got it, but there are corner cases”, in yet others “it works, but we don’t love the results enough” – with the third being the 3D engrave, where you have to make a curved gradient to get a straight line…
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No because the beam is always a cone, so when focused at the bottom it would be obstructed at the top of the trench if it had a vertical side. As you go down you have to move out so the cone is clear of the edge. That leaves a sloping side. As it is true for both sides of the beam you need to make a V shaped trench by engraving it wider at the top to allow the cone to enter when you focus lower.
The focal length is about 2" and the beam will start out probably about 4 or 5mm so that gives you an idea of the cone shape. It isn’t a perfect cone because it doesn’t focus to less than about 0.006" and that gives a straightish bit like the middle of an hourglass.
That is for @dan to answer. It is one of the advertised features that it will use the two cameras to allow precise alignment. I don’t think it is implemented yet.
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I agree, the “working on it” is rather vague. Just my impression (and that’s all it is), is that they are still working to perfect the aligning through the camera system. Most of the other “still improving” areas seem to tie back to that. In the case of the flip cut it ties directly to that. I know from what dan has said they are trying to make everything as fool-proof as possible to make it as easy to use as possible, which takes a magnitude of work far beyond what most other products try to achieve. But like you, part of me wants to know the details–but if I did then I would have to keep them secret and that would suck.
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Not certain this will help your understanding of the process in general or GF’s implementation in particular, however, Russ at SarbarMultimedia has done a video featuring the ramp function as used when engraving using a CCL. Not sure if it is this one or this one.
Thanks for the help! I will check out the videos.
edz
Basically they’ve cut the piece in at least two passes. The first pass is a (or the first few passes are) deep engrave(s) and the second pass (or final pass) is a standard vector cut. The first pass engraves a channel that clears a path for the laser to come in and do a vector cut.
Think of it this way…
Let’s say you had a 1" thick piece of wood, let say it’s about the size of a business card (3-1/2 x 2"). Let’s also assume that we know the Glowforge is capable of engraving this particular wood 1/4" deep. If you were to “engrave” the entire piece of wood, you’d reduce the thickness to 3/4". The new dimensions would be 3-1/2 x 2 x 3/4". If you were to repeat that process, you could take it down to 1/2".
If your goal was to end up with two pieces that were 3-1/2 x 1 x 1/4", you could do the whole-surface engrave one more time to get it down to 1/4" of thickness. Then you could come in and do a vector cut to split it into two.
Or, if you wanted two pieces 3-1/2 x 1 x 1" (or close to that) you could engrave just a channel for the final cut, instead of engraving the whole thing.
If you don’t want to move workpiece and with the 1/2" of focus range of the head, the maximum depth you could cut would be 1/2" + whatever thickness you could normally cut with a focused beam.
For instance, if the laser is powerful enough to cut/engrave 1/4", you’d be able to get through 1/2" + 1/4" for a total of 3/4". You’d do one 1/4" engrave at the top of the 1/2" of focus range, then a second 1/4" by bringing the focal point down 1/4", then do a third 1/4" by bringing the focal point to the bottom of the range and doing a third engrave (or a cut).
… at least, I think that’s what they’re doing - pretty clever!
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Honestly, we didn’t plan to be able to do that, but with some careful experimentation we figured out settings to make it possible with Proofgrade hard maple & walnut. Likely can do it with other materials too. The secret is going slow and removing a wide area of material on multiple passes so the lower-focused lens can do its trick.
It is 1/2".
Going thicker than 1/4" is very slow, so I wouldn’t plan on doing it regularly.
The slope is, if my recollections of trigonometry serve, <2 degrees.
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Theoretically true but as yet untested.
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That agrees with my experience cutting with an Epilog machine.
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