Incorrect operation with D1 Pro and Infrared Laser

RadicalDad · January 3, 2023, 11:59am

I have a new xTool D1 Pro with the optional 1064nm infrared laser. I need it for laser engraving (technically, laser foaming) on ABS plastic. The xTool Creative Space software worked pretty well on my very first attempt. Sadly, the Creative Space software text function is not Unicode compliant which I need for this application, so I’m trying out LightBurn. So far, LightBurn has been a total bust with the 1064nm infrared laser. Not sure if this is a LightBurn bug or user error.

For my first attempt with LightBurn, I used the same power and speed settings that had worked with my single experiment using Creative Space. I had to stop the LightBurn test almost immediately because I was afraid I would set the ABS plastic on fire. The laser was melting the plastic, not foaming it. I made several attempts, increasing speed and/or reducing power, but getting basically the same result every time. I started with 60% power at 100mm speed and ended with 30% power at 300mm speed. I also increased the line interval from 0.03mm (where I think it should be set based on the 0.03 spot size of the xTool infrared laser) to 0.06mm. As I said, the result was pretty much the same for each test. See photo.

No matter what speed or power settings I used, the downstroke of the capital P, the descenders on the lowercase y and p, and a goodly portion of the number 2 were all melted instead of laser foamed.

Note that I successfully used LightBurn to engrave a “Laser in Use” caution sign on birch plywood with the 455nm laser using power and speed settings first tried with the Creative Space software. That sign came out pretty much as expected. (I tried experimenting with wood first, figuring that accidentally setting wood on fire would be far less dangerous than setting ABS plastic on fire.)

Also note that I have two definitions for the D1 Pro machine in LightBurn - one for the 455nm laser and one for the 1024nm laser. These definitions were set up using the lbdev file for the D1 Pro available from xTool, and then modifying those defaults for the 1064nm laser as recommended by xTool.

What’s going on here? User error or bug? Given that the power/speed settings for the 455nm laser wood sign worked about the same with both software packages, but the 1064nm laser power/speed settings did not, I’m going for bug, but I’d be happy to be proven wrong.

How happy? REALLY HAPPY. I’m leaving for a conference on Thursday and need to have prototypes ready to take with me. FAST HELP APPRECIATED.

berainlb · January 3, 2023, 1:38pm

Can you provide the following:

screenshot of Edit->Device Settings for the IR laser profile
screenshot of Cut Settings window open for the layer used
full screenshot of LightBurn with design loaded and ready to burn with Cut window and Laser window showing.

RadicalDad · January 3, 2023, 7:52pm

Screenshots as requested.

Thanks so much for your help.

berainlb · January 3, 2023, 7:59pm

2 adjustments I suggest:

disable Constant Power Mode in Cut Settings
enable overscanning in Cut Settings

Between disabling variable power and not having any overscan your laser is likely overburning during acceleration/deceleration at the edges. It’s happening on the left side of the P and I suspect less obviously on the right side of the number. It’s also happening on the tails of y and p since those represent the left and right edges of those horizontal lines.

RadicalDad · January 3, 2023, 10:00pm

Well, that’s what I get for following directions! The instructions from xTool say to turn off Constant Power Mode for vector graphics, and I assume letters are vector representations. The xTool instruction graphic also shows overscan being turned off, so I did the same. I can see that the laser slows down when doing the descenders of the lowercase y and p, and it makes sense that it slows down at the right and left edges, as well as in the curve of the 2 (now a 3 but whatever). Didn’t put 2+2 together.

I’m about to try your suggestions, but I wanted to catch you before the end of your work day (don’t know if you are a volunteer or an employee, but judging from the time of your initial response, you seem to be on the east coast of the USA.) So…

What SHOULD the Line Interval be for the xTool D1 IR laser? The specs say the laser spot is 0.03 by 0.03. Shouldn’t I set that to be the same in LightBurn? I’m surprised I didn’t see scan lines when I increased the LighBurn measurement to 0.06 to get more distance between scan lines in hopes of reducing heat on the ABS surface.
I’m also surprised I didn’t see very much difference between runs as I increased speed and reduced power where the laser foaming worked correctly. I’m surprised at the latitude. Any speed/power suggestions for laser foaming on ABS? I know ABS formulations can vary, and some formulations have additives to increase the foaming contrast. Just trying to increase my personal database here. Anything helps.
In forums dedicated to laser foaming with fiber lasers, I often see suggestions to try two passes for increased contrast. Have you heard the same? Again, I can try all this myself, but adding to the personal knowledge base at this point will help me get to the airport on time!

Thanks sooooo much for your help! I’ll post results so everyone can see, but it might be a few hours. My wife left for Denver already to visit with friends before the conference, so I’ve got dog-walk duties. Some things can’t wait.

berainlb · January 4, 2023, 12:29am

I don’t have direct experience with that module but I think the .03 mm is a good start. However, I would suggest running an interval test (under Laser Tools) on each specific material you plan to engrave to make sure you’re optimizing for that. It’s very possible that your measured dot size doesn’t actually match the claimed dot size.

It’s very possible that the material itself will only allow for a certain resolution. And I’m guessing for ABS that ideal interval will shift the more you burn. Meaning ideal line interval at one cut setting may be different for another cut setting.

Sorry. I’m completely unfamiliar with the IR laser module and/or burning on ABS. One thing I’d caution is that burning ABS releases toxic fumes and can create hydrogen cyanide from what I understand. You’re going to need very good ventilation to work safely.

Sorry. Again, unfamiliar but hopefully someone else here who’s done this can speak up.

Looking forward to seeing how you fare. There’s been some interest in these IR lasers on the forum so would be nice to see some new outcomes.

RadicalDad · March 26, 2023, 10:25pm

I have continued experimenting but am still having issues. Rather than continue this older post, I’ve created a new post to continue the conversation.

See Inconsistent results: LightBurn, D1 Pro, or not possible at this price point? - LightBurn Hardware Compatibility [OFFICIAL] - LightBurn Software Forum