How precise is the Glowforge?

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#1

I guess my question is, how small of a dot can I make, AND, what is the minimum distance between dots?

I am new to all this. I am trying to think of all things I could use the Glowforge for. Could I, for example, use it to create gratings or lenses? Thanks all!


#2

Hi @omar.bakht. Welcome!

Some of the answers you are looking for are here.

Positioning precision to 0.001” (0.025mm)
Engraving at 1000 DPI with 256 power levels

The spot size is a little more difficult to quantify.

Laser Quality — Beam diameter of less than 5mm at aperture and divergence of less than 1.2 mrad

At the focal point, its dependent on the material.

Here is a thread where they talk about it some more.

I believe someone else was talking about wanting to make Fresnel lenses with their Glowforge.


#3

You wouldn’t be able to make a “dot” any smaller than the kerf (~ .008" I believe). The accuracy of .001", would be location precision of the bipolar stepper motors that drive the X and Y axis. The pros can maybe correct me on this if I’m misunderstanding things.


#4

there’s also the consideration that the kerf is the width of the ablated material and doesn’t (as far as I know) include the burnt edge to either side. So if the question of smallest dot is actually asking the smallest hole it could create, then a hole with a .008" diameter is the theoretical limit. But if you were trying to mark the smallest visible dot, I imagine it depends largely on the material and power settings but will be larger.


#5

At lower powers you might be able to make a dot smaller than the kerf, because the intensity falls off toward the edges of the beam. But I wouldn’t want to count on that for production. And certainly not without a long test process.


#6

The spot size is about 0.006" if I recall, typically resulting in about 0.008" material removal when you cut through. That defines the smallest dot or thinnest line you can make (and as noted, theoretically by experimenting with speed/power you could get smaller still). But the positional accuracy is better than 0.001, meaning you can create very smooth curves, much more so than if your positional accuracy was 0.006.


#7

I know in other laser software one can set DPI or scan gap for raster engraving, which impacts the circular overlap of the beam. I assume we will have the same control?


#8

I believe this thread was made for you.

so 1.3k lpi not exactly dpi but you can see in the thread it is adjustable.


#9

Thanks, everyone! I am by no means an expert at this sort of thing, but I work in an institution known for lasers and laser precision. I was just wondering if I could replicate some of the work being done here. For example, we have a project where one of our scientists can make materials super hydrophobic or hydrophillic. He uses a high energy femtosecond laser though. Me - I just want to make things out of paper and cardboard.


#10

@dan, Hey Dan, after you are done fulfilling these orders, let me know if you want to get into crazy laser stuff.

Like, why couldn’t we attach a more accurate and more powerful laser to the Glowforge system to do loony stuff like super-hydrophobic metals? In the future though. Don’t want to distract you from getting me my Glowforge.


#11

Micro-structures are fascinating.
Nature’s 3.5 billion years of trial and error have resulted in many uses of them, in this case using the surface tension of water to control how it behaves.
Other structures refract light and produce color, or a specific wavelength through constructive and destructive interference.

Many times when we become aware of physical properties we can produce then we look closely and find nature has been there and done that.

The answers have been there all along, we just didn’t know how to read them. - Carl Sagan


#12

Well you had my attention at “crazy.”