Diode laser - moving normally, showing light, not engraving

Community Laser Talk
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Hello, I’m a total noob when it comes to engraving.

I’ve had the TTS-20 Pro from twotrees for 2 days.

I have made some tests yesterday, everything worked well.

Today I tried engraving a zippo lighter and I noticed that 0 markings were made at 80% power on the lighter, at first I figured that maybe the material of the lighter is at fault, I tried giving it 100% power anyways. Absolutely 0 markings.

I gave up, I then tried on wood and again 0 markings.

Figured maybe some of the settings in lasergrbl were wrong, I did a fresh reset of everything, still 0 markings. (I tried typing $RST=$, didn’t work, also trieddeleting all files from C:\Users{UserName}\AppData\Roaming\LaserGRBL to get a fresh start)

The machine moves as it’s supposed to, it fires some fainted light when doing so (when it was actually engraving, the beam was more powerful).

Is there any chance that I don’t have a faulty diode?

Everything I find online is about replacing the diode

(Checked all of the cabling, everything is ok, also cleaned the lenses of the diode)

1 Like
2

If you were trying to engrave a metal Zippo, the beam may have reflected back into the laser, destroying the diode.

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So much damage after only one engraving?

4

Obviously I don’t know for sure, but I’ve seen several warnings about the reflection from engraving metal burning out the diode. I would recommend reaching out to the manufacturer. You may just have a faulty laser. They should be able to run you through any testing process needed.

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Thanks, I contacted them and awaiting a reply.

It is stainless steel and on the label they say it can engrave stainless steel, but I don’t know tbh

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But theoretically, if it was damaged by the reflection of the laser, would changing the lens solve the problem ?

Again, there is light that comes out of the laser module, the fans from the module also seem to work just the same.

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Does the light appear to be a pinpoint, or is it disbursed?

Did you refocus the laser after changing from the lighter to wood?

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It is disbursed

I didn’t refocus as I don’t really know how

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That is the first thing you need to do then. Look at the manual, watch youtube videos, whatever, to learn the basic operation of your machine. Many lasers have a flip down leg that you place against the workpiece for focus. Some come wiht a focus block separately that you need to use. You need to understand that before going further. This video shows you how to do a ramp test to find your perfect focus. Often times the focus tool provided with the laser is close but not perfect. Watch some of his other videos to get up to speed on Lightburn and lasers in general.

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I understand that I need to learn a lot of things, including focusing.

But even without refocusing, shouldn’t it be able to engrave at least a piece of paper tissue ? (Used a red one)

Because there is literally no mark on it

11

Depends on how far out you are and what settings you used. Try doing a ramp test and see what results you get.

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1.5cm from the laser module, 90% power, 2000mm (it’s a 20w laser), didn’t leave the faintest mark on the paper

Here is an example of how the light looks on wood (90% power, 1000mm) : PXL_20241027_162634457.mp4 - Google Drive

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Let’s look at some basics. Maybe I’ll see something here. Please post a screenshot of your entire Lightburn screen with the Cuts/Layers Panel and Laser Panel visible. Also post a screenshot of the Settings Window (Gears icon) with the Units and Grids tab visible and post a screenshot of the Device Settings Window (Wrench and Screwdriver icon). You can drag and drop the screenshots into your post body.

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This video looks like you focussed way too high.

I think Tim is right here. If the beam is not looking like a clear spot, the optics could be damaged. Usually, you can’t replace the outer lens, since the mirrors or diode itself is damaged. The module needs to be replaced then. But you can do some further check. Show a picture of the wall test (as described here: https://diode-laser-wiki.com/documentation/guide-to-mechanical-adjustments/)

And, another thing to add: this is a LightBurn forum, you seem to be using LaserGRBL, which is not really supported here.

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Thank you for the reply, this is the wall test for 1m : PXL_20241028_085013587.jpg - Google Drive

https://i.imgur.com/zutTSOp.jpeg

It’s a TTS-20 module, 20w (4 diodes, 5w each)

I tried the lightburn autofocus test, nothing happened

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So further update, I took this part out, it has glass inside, it’s right under the nozzle, it’s clean: https://i.imgur.com/CREpD2X.jpeg

Underneath is this glass : https://i.imgur.com/Vj6AE0t.jpeg

The second piece of glass has either debris underneath or it is burnt, don’t know for sure.

My question is, what is the glass in the second picture, is it the lens or is the lens in the first pic?

I’m tempted to try to take the rubber from the outside of the glass (second pic) and see what’s underneath, maybe change it if that’s the lens, but I want to know if that’s the lens or not

My guess is that that’s the lens, and the first pic is simply some protection, but I might be wrong

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The first picture is the protective lens. This one can be replaced and keeps particles away from the second lens (second picture) which is the focussing lens and part of the optical beam forming. If that one is broken, it can’t be replaced usually, because you need a lab to align it properly.
I don’t know if it’s blind, but your test picture looks like 3 of the 4 diodes are dead. You should have 4 lines when you have 4 diodes.

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Thank you very much, I guess I’ll have to buy another laser module

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Noobengraver, thank you so much for posting this. I am having the same problem, only I have only tried mine on plywood and paper. At first it burned, and now not a mark at all.

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You need to read the manual for the laser.
there is no auto focus, Use the stepped brick to set the focus.
the beam should be 0.4 mm x 0.4 mm dot if I remember.