Double sided cut



Just curious if there is an example of a double sided cut/engraved that had to be precisely aligned. I know this has been promised, but I can’t seem to find a good example of a double sided example, and specifically a double sided project that needed the GF ability to precisely align both sides to each other (assuming using either an edge or registration point or something like that.


I am also interested in the answer to this question.


No, the software for double sided alignment isn’t released yet.


I think this is supposed to come around the same time as the passthrough software. Makes sense since it prob uses the same type of object/feature recognition


I thought you were saying that it was actually working

Ohhhh, it’s still in the “To Do” category here in the pre-release announcement:


@julybighouse, I tried searching to see more from your first quote. Where did that come from? I am really disappointed to hear that the double sided cutting only works for “common cases”. I wanted to read more from that post, but i can’t seem to find it.


I think it may have been a discussion on HOW double sided engraving would work.


What sort of not common case were you thinking about for the double sided cut? It’s designed to work with more than just rectangles (cases with a well defined edge) It would be impossible to flip a circle and figure out the relationship between the material and an image partially cut on the blind side. Can’t cut all the way through for a reference because the inability to cut through thick material is why double sided cut is to be provided. Seems to be a reasonable design limitation.


We know that jigs and indexing tabs built into the design will work for the double sided engraving. Nothing else has been discussed by Tony or Dan so far.

BTW @julybighouse, I’m writing up a little quick explanation of the workflow for creating that file that I told you I’d help you with, so you can do your engraving on the bottom of your mugs while you cut them out. (It’ll be the first and easiest method, just substitute text for the center hole and place it wherever you want on the circle.)

Probably finish it later or early tomorrow. :slight_smile:


THANKS! And this is one of the problems I was thinking about. With a round bottom, I’m going to have several challenges to get the text centered properly. I also wasn’t sure if someday I’ll want to do something incredibly fancy/weird with the bottom and might need a reason for the double sided registration to be needed. It really could be a thing where I keep a tab on a particular side and base all of my laser registration off of that tab.

As for the precision of the double sided cuts for @rpegg, I’ve heard of others who wanted to create double sided circuit boards where the alignment of both sides are critical, and I realized that I hadn’t seen this feature yet and no one seemed to be asking much about it.


Proofgrade™ UV QR code for orientation? It’d mean that you’d have to use Proofgrade™, but…


@rpegg I am a pro purchaser. I imagine that the software/hardware interaction will need to be very exact when using the pass-through slot and the double sided cutting will require similar exact interaction. I was expecting, lacking any caveats placed in the “Tech Spec’s” section, that you could cut something like the tree in my post here out of 1/2 in. (12.8mm) thick material. This ability to link the camera on the laser head to material position will need to be very exact for it to be useful when cutting.

They say “[cut] twice as thick by reversing and cutting from both sides with optical alignment”. They do not say anything else. I would think that if I cut a circle in one side of a piece, that if I flipped the piece over, that the Glowforge could cut out the other side with the same precision.

I think that this would be very hard to do. Which is why when they advertised it, I wanted to buy it. Except for @julybighouse post above, I have not seen any limits placed on the double-sided cutting promise in the advertising video.


The “Common Case” that Dan was referring to had nothing to do with the complexity of the cut. It was the ability of the camera to recognize the material position (not the cut) from the back side once it was flipped. It’s relatively easy to recognize the position/rotation of a rectangular piece of material flipped over on the longitudinal axis. It impossible to recognize how a completely circular coaster is positioned from the back. It will look the same no matter how it is rotated. That’s what was meant by “Common Case”. No clue as to when the double sided cut capability will be available. Obviously we have as yet no idea the precision.


When you flip the material you can’t see the the front side QR Code.

From Dan’s comment I take away the following: If the original material is a rectangle or other easily recognized shape then the S/W should be able to recognize how it is positioned once flipped and any small rotational differences. So the desired cut could be completed. If the original material is a circle, like a coaster, when you flip it there’s no way to figure out what’s the top. It’s impossible to account for that. The capability is not finished yet. We don’t know how well the S/W will determine complex material shapes. So “Common Case” is TBD.


I was thinking more along the lines of, if you wanted to cut a circle and the QR codes were oriented the same way on both sides it would be able to tell how much rotation has occurred. I think the corners comment was about how they’re trying to get the pass through slot to align. Could be wrong, though.


The recognition technology might be the same between the pass thru and the double sided problem, but Dan’s edge comment (copied from another topic) was about aligning for the Double sided cut. We have no idea how well it will work or when the feature will be released. I was just explaining to @dpmarkman that nothing in Dan’s comment suggests the described use case is problematic, as long as the original material is a shape that the S/W can recognize once flipped.


that is an interesting idea. I wonder if it is feasible.


Might get you a rotation angle of ??? accuracy, but still need the optical recognition S/W to determine X/Y placement to continue the cut. Either way, wouldn’t work for non-Proofgrade. It is all academic though. Have no doubt that the double sided cut using the overhead camera for alignment will soon work just fine for most cases.


too bad you cant just have a little clip like a binder clip with markers on each side that you clip onto a random spot on each material and shows on both sides so it has something to visually lock onto


Have absolutely no doubt that the optical recognition will be able to figure out a wide range of material shapes to register the mirror image from the back blank side. Will it be able to recognize weird shapes on initial release? Maybe not, I have no idea, but with time and improved cloud S/W, as long as the material isn’t made up entirely of smooth curves, I’ll bet it will satisfy most use cases. (And I rarely assume anything.)