Hey!
So while I am still cutting, troubleshooting etc on my newly built CNC, I think that maybe a laser would be cool to add. I did some research and watched some videos on the NEJE A40640 II laser. Sounds like the second version of this laser recently got released so I was wondering if anyone has had installed it on their MPCNC with an SKR Pro? How does it cut and also raster (as I will be mostly doing some rastering to engrave images and text)? Is it sorta quick?
I also had a question about wiring upon arrival so I know what I am getting into. Reading the documentation it looks like the only wiring needed from the adapter board of the laser to my SKR Pro is one wire that goes to pc9 pin and a ground wire. Is my image below all? This would then be used as a PWM signal to tell the laser to turn on and off when needed. Other setup would include mounting the laser, wiring from the laser to the adapter board, then wiring another 12V power source to the adapter board for the laser. Am I missing anything?
I have an older A40640 (before it came with air assist stuff) which Ive used on a few different control boards. I also have an E40 with the air assist stuff I’m using on my extrusion frame laser.
It works well enough, I basically use it for raster lasering
You are not missing anything. I too have the earlier version of this laser with this same control board. I’ve used it a lot.
If it makes your setup easier, the control board is not required. It is there to provide simplicity for the wiring. If you want/need to wire things up without the laser control board, let me know, and I can give you some pointers.
I used my laser for a lot of laser cutting, and I noticed some charring where the laser plugged into this board (four pin connector). I ended up rerouting the power to the screw studs.
If you are going to extend the four-pin wire between the laser and this board, I recommend using some larger wire for the two power wires than is used on the provided harness.
As for the ground Tom mentioned, that is provided for when using this laser control board by the ground wire between the SKR Pro and this control board. You would need to make provisions if you decide to wire your system without the laser control board.
Thanks for the info. I did not know about the common ground connection. You learn something new everyday. Looks like the package online comes with the tester board and transfer board so I will probably just utilize that.
How does this laser do with rastering images onto wood? It looks like the quality is pretty good on other setups, not sure about MPCNC. The new version of the laser says no air pump required but has a connection spot for the air nozzle. I guess we will see how that works.
If you use the board, it can be mounted anywhere. It can be mounted on the core for example. Personally, I mounted mine on the ceiling of my enclosure.
How does this laser do with rastering images onto wood?
The laser does well with engraving, but the process is slow. The issue is the MPCNC is tossing a lot of mass around, so the maximum feedrate you can go and get good images is limited. I’ve done a bunch of 4" x 4" tiles (posted some to the forum). It takes around 70 minutes to complete a full tile (i.e. where the entire tile is engraved) at 300 lines per inch. I’m not happy with the results if I go faster or reduce the lines per inch.
A few points:
Make sure you dial in the focus distance for your laser. I found this to be a difficult task, but worth the effort.
I needed to make some scanning offset adjustments to get clean engraving. Lightburn reference.
Air assist, even a modest one, is very important for laser cutting. It keeps the smoke away from the lens, it blows the smoke out of the cut to allow the laser better access, and it suppresses flames.
If you do an air assist and the tubing run is longer, I recommend a running larger diameter tubing for most of the distance. I originally ran smaller tubing and was surprised at the reduction in pressure.
If engraving on a light colored wood, spraying with a borax solution first will increase the char, creating a dark engraving. You need to clear coat the result since the char smears.
One thing you might do is take a look at David’s (dkj4linux) posts on laser engraving. In at least one of them, he provides tutorial-like information. I originally used YouTube tutorials to learn about laser engraving, and my results were similar to the videos. Then David posted his beautiful images making me realize the laser was capable of much more. It took addressing the things in the previous post plus some experimentation plus learning about image preparation before I had a recipe that produced images I was really happy with.
And I believe this is a general laser issue, not just an MPCNC issue. When I look back at the results in the YouTube videos, they were not very good, and they used commercial engravers.
So I seem to have forgot that I do not own an SKR Pro but rather the Jackpot controller. Which pin is the PWM pin? The documentation seems to have SKR Pro, Rambo, Mini rambo and Ramps. My laser came in the mail over the weekend.
