Can the GlowForge cut Brass?

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#1

I am thinking about the amazing things I can do with my new GlowForge and I wanted to know if I could cut .012 brass. I typically do photo etch, but I might be able to get more details from the laser. And save money on the tooling. Plus get more scribing details into the brass too.

Thanks
Eric
Homeport Models


#2

My understanding is that a 40W laser won’t cut any metals at all, regardless of thickness.


#3

Im glad I got the PRO 45W system then. :smile:


#4

Unfortunately the same goes for the pro 45w won’t even close to cutting it. You’ll need a fibre laser or plasma cutter or cnc router/mill to work with metal efectively. CO2 laser just don’t have the power


#5

I’m no laser expert, but we use a YAG laser (outside service) for our stainless steel and titanium - much more energy in the beam. Water jet is slower but another viable option.


#6

Brass, copper, and similar alloys are particularly difficult, but there are lots of CO2 lasers that can easily cut metals, particularly ferrous metals. Those lasers are usually running from 100 Watts to more than a kilowatt in power and their cost is also several orders of magnitude more than a Glowforge.


#7

You should be able to laser cut masks for your photo etching. So mostly your current process still, but with higher detail gained by having the laser anyway.


#8

The challenge is that metals are fairly reflective at CO2 wavelength, so it needs a lot more energy to cut them than an equivalently-powered YAG or fibre laser. (The reverse is true of wood and acrylic; CO2 frequencies are best for those). But @jacobturner is spot on - the big opportunity is the mask, etch, then engrave.


#9

Would one of those fancy frequency doubling devices adjust the wavelength and increase the rang of materials for the Glowforge if it could be introduced into the optical path or are we talking a very large jump in wavelength or the wrong direction?


#10

What frequency doubling device are you talking about?

Light travels at one speed and one speed only. That property means that the frequency is directly proportional to energy. So you cannot simply double the energy of random light on a whim, you need to provide the same energy the light already had, and doing such a thing will be what causes the frequency to double.

The energy imparted by the laser (ie - 40W vs 45W vs 20,000W) is not a product of the frequency of the light, it is the intensity of the light (amount of photons per second). That is why being at the focal point is so important (most photons per area).

EDIT: Okay, I didn’t take the question fully in context of the post by Dan. You mean to shift the frequency, at a loss of energy, just to move out of the reflective wavelength regime?


#11

I’m pretty sure Jacob hangs with Sheldon and Leonard… no arguing with physicists. :smile:


#12

so I’ll admit not much understanding. but I believe something similar to:


is used to adjust the wavelength of a infra-red laser to make a green laser pointer. And while I’m pretty sure it wouldn’t be able to make it into the basics or the pros being worked on now. I do wonder if the range of materials that aren’t too reflective of the CO2 laser tubes could be adjusted similarly.


#13

The SHG process massively drops your power output. Orders of magnitude of power loss. Which for a laser pointer is no big deal, they are already really low energy, and in the end just need to be visible. But for a laser cutter, you are talking about moving your GlowForge 40W laser down to somewhere around a 40 mW laser (I don’t know any simple formula to calculate exactly what the losses are, but a 0.1% yield is a reasonable estimate). At that power level, popping a balloon is only barely possible.

The nonlinear optics devices let in the laser (photons), and then bounce those around atom to atom in a matrix for a little while (in our terms, no time at all. In light terms, trapped). A new set of photons comes in, and also get trapped, into the same atoms in some cases, and this results in higher energy photon release happening.

This doesn’t happen for absolutely every photon released. Many are still released at the same energy they came in at, and some are released at intermediate energy levels (the levels are quantized, so having intermediates depends on energy in, and material of the optics). If your use case demands only having the higher frequency laser in the beam, you need to pass through a filter to trim off the non-doubled portion of the beam.


#14

Thanks for dumbing it down till I got it. Eyes were glazing over trying to figure out the article fully.


#15

The joy of being in physics is understanding everything, and being unable to do anything practical with that understanding :slight_smile:


#16

Snort!


#17

I’m sorry, but with Back to the Future Day just last week… I believe we are looking for a flux capacitor.


#18

There definitely needs to be a nerd badge added to the forum and I nominate @jacobturner for the inaugural issue.


#19

Can the GlowForge engrave on metal such as brass?


#20

This thread among others addresses this complex issue:


It seems that there are some treatments you can use to allow some type of “marking” of the metal. Whether or not we can call that engraving or not has been hotly debated. Leaving deep tool marks like you would have with a carbide cutter: no. Leaving some type of visible marking, possibly. Depends. It seems the previous parts of this thread have explored this.
Also the tech specs page at Glowforge in the materials section: https://glowforge.com/tech-specs/