This is what they look like coming off the laser - you have to pick a bit at the white parts to crumble them off, but there was no burn through on this one, or the dye inside the egg hides it.
No they are cut throughs. The dark line in the center is just a little edge discoloration from the smoke of the membrane - you see it on the other side as well.
The white looking part is the actual egg shell damaged by the laser beam - it almost seems to melt into a thin cement-like substance at the edges of the beam - the egg shell itself is not being burned, as far as I can tell. It crumbles into a superfine powder when poked, but it is stiff.
(Kind of reminds me of what happens to Royal Icing when you let it sit out …for those of you who decorate. It gets rock hard and stiff, but with no side strength, and crumbles at a touch.)
FYI: The effect you are seeing is similar to what I have been getting trying to cut Mother of Pearl. Both the eggshell and Mother of Pearl are primarily calcium carbonate.
To report a failure: I can get through the MOP with high power or even many low power passes but I’ve determined that cutting thick MOP (0.06") is pretty much impossible to get a clean usable cut. It shatters, burns or turns into a cement that clogs the cut. No power level, speed or number of passes has given anything worthy of using for an inlay. That’s not to say that much thinner material or Mother of Pearl laminates might not work. But not the thickness that is typically used on fretboards. Will try the very thin laminates after I can get some in. I suspect those will work but they are mostly just decorative vs. decorative and durable.
I don’t know how you could get through this if it were any thicker. It really does just kind of melt into cement.
I’m switching around the focal point to try to get something that creates a thin line, which is tough because the eggshells have a lot of curve to them - more than the devices that people want to engrave on later will have. It’s spreading the beam.
(That might get better once they implement the true 3D engrave function later, for now, I’m having to take a SWAG at the midpoint of the curvature. Not terribly successfully yet.)
“When an axicon/lens combination is used with a CO2 laser, the cutting time was further reduced to 0.2 seconds per egg and the mechanism of material removal is changed from vaporization to decomposition of the eggshell into fine powders.”
Very much of interest! THIS is what it does. (You have to clean the powder up after…its a much dustier process than burning wood.)
It is the continuously variable focus feature that can engrave on curved surfaces that is missing here. 3d engrave has been shown in proof of concept but not rolled out yet but I think that is quite different. In the first case the surface has to be scanned for depth. In the latter the artwork specifies the intended depth.
That’s actually a great idea - the first thing I tested on the eggs with the Glowforge interface was the Trace function, and it worked like a dream!
You can draw on the eggshells and then cut out parts of the drawing.
So if you have an eggbot, or a ("oh hell, what do they call those things?") pysanky rotator thingy, you can draw on the eggs, use the Glowforge trace function, and just cut parts of the egg out.
I’ll probably take a shot at that once I get the settings down…but I only have one egg-bot drawn egg that would work without pulling that whole thing out again. (So later).
Small CNC bits or by hand with a jeweler’s saw. I’ve only used the jeweler’s saw myself to do instrument work. This was my very first attempt at cutting MOP about 15 years ago. Didn’t really know what I was doing at the time so it’s not very fancy or even satisfactory. One piece. I easily recreated it on my CNC in laminate as a test but never bothered to use the MOP.
From the image, you have too low of an appreciation of your work - not at all unusual for artists.
That’s right, there is an artist within the engineer.
The lines that define the boy, how did you score them?
Too bad the laser has trouble, nacre and abalone were some I was hoping to work. The shattering I presume is thermal shock?
Considering the changes in residue that result from different settings, maybe it could be dialed in…?