Module laser Neje A40640 40w good or not good

The kerf on my laser (a A40640) is 0.2mm, though it varies a small amount depending on the material. Here are three luminaries I cut for Halloween to give you and idea of the kind of detail it can do:

The carved areas are all about 6" tall. I just measured, and the thinnest areas on the koi were .45mm thick, and the thinnest lines (around the teeth) of the Attach on Mars face were about 0.65mm. But with that said, it’s not a slam dunk. If there is any tension in the material, it can curl up and get in the path of the laser and ruin the cut. And as mentioned above, when I turned off my air assist, the bag caught fire.
So I think you are pushing it if you have a lot of windows with only 0.55mm of separation, but it is theoretically possible. It will depend on the nature of your material and how you present it to the laser.


Thicker materials will tend to have a larger kerf. Lasers are slightly cone shaped.

What is that plate with all the spikes composed of? Looks like a good bed to set a burning project on.

1 Like

Based on seeing some in various K40 articles, I’m guessing it is made from something like these.

1 Like

Cool. thanks

You might try these if you want to avoid reflections.

1 Like

LOL! During my laser “travels”, I had always been keeping an eye out for a good “bed of nails” design… when I came across a video (no clue where I saw it now) where a guy had found a “goth” apparel shop online (Ebay?) where they sold all this spiky stuff, popular with “those” folks. Anyway, a bag of 100 metal studs and screws was inexpensive enough I bought a bag. Printed a plate with counter-sunk hole pattern and assembled it (very tedious!) into a bed of “nails”. Unfortunately, when I packed for the move back to East Texas I lost track of it and only found it a couple of days ago… I had never had a chance to use it!

Anyway, playing with this big diode laser, destined for my daughter’s laser engraver, I’ve been trying to get my miniFoamRipper machine set back up for actual use again. Bought a 24" x 24" steel sheet from Lowes and I’m hoping now to start doing productive stuff again… it’s been a welcome diversion :stuck_out_tongue_winking_eye:

– David



And… yep!

I just grabbed a sheet of the white honeycomb light diffuser stuff from home depot. Not quite as fancy, but it’s worked well for ‘through cuts’ on the laser. Plus it’s plastic, so no reflections. It does burn through over time, but I’ve yet to have to replace it.


I picked up a sheet of steel lath from Home Depot last week for use as a laser bed for larger laser projects. It was $15 for a 27" x 96" piece. I have yet to use it (I have a smallish piece of aluminum honeycomb for smaller projects), but it looks like a good fit as a larger laser bed. From what I’ve read, you don’t need much separation below the material when laser cutting.

1 Like

Thanks for your comments and photos of your work. My friend uses Lightburn at the makerspace, so I’m sure he’d stick with that. And, he tells me that he’s familiar with the necessary offset for the kerf width. And, clearly your experience (and of others) confirms the need for air assist.

I think the primary concern was whether the optical limits (inherent beam shape, etc. of the 40640 laser would allow these dimensions, and your results indicate that, while challenging, it should be possible.

So, back to the OP’s original question… is the Neje A40640 laser module any good or not? Given a couple of days to play with it… I say “Yes!”

It’s performance far exceeds any other diode laser I’ve ever had… and how long it lasts remains to be seen. After a bit of testing to find best cutting speed for 3mm (1/8") birch ply, I was able to cut everything but the heart-tree in the following photos in a single pass at 200 mm/min and 100% power… the heart-tree required 150mm/min and 100% to get all pieces to fall out without breaking small branches.

In addition to the air-assist mod we’ve already discussed, I’ve discovered that small 40mm x 40mm x 11mm CPU heatsinks make a great “bed of nails”…

They’re very effective and are easily spread around to support any size workpiece… and a bag of 10 heatsinks is reasonably inexpensive to solve what in the past has been a nagging problem. I’m hoping they should be easy to clean with a cleaner of some kind… any suggestions?

These cuts are easily done with my CO2 laser and much faster, of course. But this diode laser setup is IMO much easier and convenient to use and not so slow as to be “painful”… i.e. the ~140mm x 140mm heart-tree took only 33 minutes, and way less for the other pieces. I’ve also cut several ~5mm materials in my testing as well… some in one pass and others with only an extra pass or two at most. Numerous videos are out there showing folks cutting far thicker material than that… so I’m really looking forward to playing with this Neje A40640 laser module further. I think it will really “up” my daughter’s game when I’m ready to move it to her machine… :smiley:

Again… my $0.02.

– David


Congratulations, The specifications look amazing. 0.04mm square spot, 15W optical power is amazing, combining the power of two diodes.

I just pulled the trigger this weekend on a SCULPFUN S9 Laser, supposedly the equivalent power of a 90W co2 laser as it has an ultra-fine 0.06mm fixed focus spot. Only 5.5 - 6w optical power which I thought was about as good as you can get. Supposed to cut 15mm Wood & 10mm Acrylic.

I am so envious now. I thought I had done all my research, but missed this one. Damn Youtube, you let me down.

Did you have to do some sanding to fit the air assist? I’m having problems to push the end in.

It looks like it is pushing against the back side of the copper coloured ring but it is hard to see. So I was wondering it you had the same problem and how you fixed that.

I had to us a stepped drill bit and ream out the hole for mine to fit.

1 Like

I had to slightly clean out the slots for the mounting screws, but mine fit with respect to the copper ring. The fit may depend on the 3D printer and material printed. Note that the placement of that ring is different on the 30W vs. the 40W lasers.


It looks to me as though you’ve printed the 30W nozzle vs the 40W nozzle? The 30W has a centered lens assembly in the module body and the 40W is off-center by several millimeters. The one with the centered conical section is for A40630 and the off-center for A40640.


FTR, I printed the 40W version. It was a tight fit over the lens, but it fit without any filing or drilling. If you have an elephant’s foot, I could see needing a trim.

I think David is right though, wrong version. Easy fix.

1 Like

Above the copper ring is a plastic “ring” to focus the lens, that goes perfect in the air-assist print. It is only the copper ring, that is slighty bigger then the plastic ring, that doesn’t goes in.

I will give it some sanding to make it fit. Thanks all for the fast respons.

1 Like