Four ways to laser glass

MancraftingTM on Youtube just put out a video on laser glass using 4 different methods (wet paper towel/wet newspaper, masking tape, dish detergent, and glass laser tape. )
It’s hard to compare since he did different styles of glass for each technique, but it was interesting to see some comparison. Seemed to be more of a sponsored video for the rotary tool he was using, which looked pretty nice as well.

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I put a chunk of glass in my glowforge with no prep whatsoever, just bare dry glass, and it etched absolutely beautifully. I’m kinda wondering if it would be even better with water, but that’s almost hard to believe.

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To be honest I haven’t tried to etch glass yet so I’m not real clear on what these prep techniques are trying to avoid. I think I remember something about wet paper being used for keeping thin glass from cracking due to potential thermal stress?

Other sources say that direct etching leaves a rough surface, and wet etching reduces roughness.

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I’ve just built a rotary for my K40 :

In the past, I cut vinyl and sandblasted with a homemade sandblaster, which produced this quality :

The finish is perfect, but as you probably all know, you can’t get the detail with vinyl - hence the reason for building a rotary.

My first test came out like this :

That was dry, on low power (sorry - don’t have the value to hand at this point). It doesn’t feel as rough as it looks, but it doesn’t look as polished as sandblasting.

Anyway - I revived this thread because I’m going to do some testing, and for anyone who may have ideas / suggestions, feel free to reply and I’ll test them out.

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So - I’ve been playing some more - and realized something important.

When I built the rotary, I didn’t consider the gear ratio’s at all. My engravings came out with quite obvious gaps in the Y axis :

The T2 timing wheel on the stepper and the drive wheels were the same size, but the wheels the glass rested on were bigger. So I was losing resolution in the Y.

I kept the stepper timing wheel the same, and added 50 teeth T2 to the drive wheels and things improved slightly, but still not as good as I think it can get.

I know for a fact, if I etch a flat piece of glass - I can get it as good as sandblasting.

So I’ve order 60 teeth T2 timing wheels, and a NEMA 17 with 400 steps for rotation. I’m also going to get the wheels the glass sit on to be as small as possible.

Stuff is coming this week.

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More updates … better results.

My 400 step nema 17 hasn’t turned up, but my 60 teeth t2 timing wheels did :

So I installed them on my rotary and made a new timing belt. It takes just over 5 revolutions of the stepper to rotate the 60 tooth wheel once.

This is now the quality of the engrave (160mm/s 5-8 ma)

The picture doesn’t do it justice, it does look a lot better than the previous tests.

What I find curious though is, the Rotary settings in K40W are the same - wouldn’t you think the scale factor would change if there are now more steps ? I’ve tried to get my head around it - but so far failed ! If anyone has any input of that I’d greatly appreciate it.

400 step NEMA 17 due Tuesday…

More tests done today. I don’t have many glasses in the house which aren’t covered in some kind of “test”!

All these results where done on the same glass - or at least the same type and size of glass :

160 mm/s @ ~5ma :

Masking tape (The gap in the square is just from a crease in the tape) :

Wet Paper 1 :

Wet Paper 2 (I upped to about 6-7 ma as the result looked weak) :

Washing Up Liquid :


!

As you can see, the washing up liquid came out best. It looks better, and feels better to the touch.

So I upped the power again, ~10ma, still at 160mm/s :

Clear winner.

Conclusion : Gear up your drive train, so a small gear on the stepper, and large on the drive wheels. I have GT2 30 teeth on the stepper, and GT2 60 teeth on the drive wheels. Keep the wheels connected to the drive wheels (so what your glass sits on) as large as possible too - all this will keep your Y axis resolution high.

However! : As washing up liquid is a clear winner, it might be best to hold the glass internally in some kind of chuck, as the greasy nature of the liquid on your drive rollers may make the glass slip.

Merry Christmas all - and happy making.

… and this is my final update. I installed the 400 step Nema 17 and the results are even better.

My rotary settings are now set to 1, so my X and Y resolution are the same.

This example is a bit messy, I’ve run out of glasses doing all my tests, but it gives a great finish.

Maybe this is the last edit :thinking:

I’ve just made a set of glasses (I’m showing off, but hey), look at the detail here :

This SVG is 20x20mm

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Nice! Now you are making me want to add a rotary chuck to the monocle! I really need to get it functioning before I start designing anything new for it though. :grin:

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