Hi! I want your opinion about this laser?
thank’s
That is not a NEJE laser… it is a LEHO brand. The only thing I would say is it appears to be a single LED laser so will be around a maximum of 6.5Watts of actual light energy, this is not equivalent to a NEJE 40640 which is a two led design and therefore has roughly double the output power. This LEHO is more akin to the NEJE 40630.
As to good or no good… I cannot say, ‘goodness’ is only partially down to output power as quality of the optics plays a major part in how small and focused the laser dot is. To ascertain that you need to have played with one!
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Thank’s
I haven’t tested engraving yet cause i just received it few days ago but Neje 40640 is very good for cutting.
I do 5mm Plywood in 1 pass at 120mm/min 100%, without air assist(yet).
For cutting needs you can found a small but usefull and free Lightburn material library here :
My firsts tests were complete success, without air assist do not hesitate to use masking tape to avoid smear of smoke.
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After spending the past year in some sort of weird funk/malaise and losing interest in a lot of my hobbies, I’m almost grateful my daughter’s homemade (by me) laser engraver started acting up… mostly due to poor connections in a bunch of Dupont connectors. It “sported” an early Banggood 3.5W laser module that mostly “worked” but was really “just marginal” at best for some of the wooden jewelry she’s been making.
Anyway, not having laser shopped in quite a while, and wanting something a bit more powerful, I looked at that Neje 40640 module you guys referenced… and decided to give it a go. Actually got to me in just a few days from a US warehouse… and started playing with it yesterday. No problems at all… I’d played with other Neje laser modules in the past and this one fired right up. It’s pretty impressive… through-cut a small willow bandsawn plank in one pass, 200 mm/min and 100% power.
Then I decided to look into air-assist. I’ve rather liked the setup I described in @geodave’s Cantilever Laser Engraver thread… so wanted something similar on the Neje module. The following photos show what I’ve come up with for the laser module… the rest of the air-assist setup is identical to that I described in the thread referenced above.
Here it is in action…
Replacing the amber/red window on the laser module with a simple printed part…
which fits inside the housing and accepts a 6mm air line…
and centers a funnel-shaped shroud over the laser lens
I initially used a “new-style” Neje 30W laser module (which I physically broke a few days ago) for getting my initial dimensions but – alas! – the 40W Neje unit is slightly different. Note the lens assembly on the 40W (right) is offset from center and the 30W lens assembly (left) is centered.
This necessitated going back into Onshape and shifting stuff over a couple of millimeters and adjusting the wall thickness of the funnel… and the fixed-focus laser beam exits the 3mm opening pretty well centered. The conical tip extends below the body of the laser module by 15mm and seems to focus nicely at 5-6mm from the material surface.
If you’re interested, I can provide the Onshape design files and put the stl’s out on TV… I just need a little time to clean them up and figure out how to get back into my TV account. It’s been a welcome diversion and I’ve enjoyed getting back to doing something I enjoy…
– David
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David,
I recently purchased one of the 30W modules, would you happen to still have those stl’s to share?
Also, if you didn’t see the news lately, Thingiverse was compromised - so once you do get logged back in, I’d recommend changing your password!
I found out about the TV breach when I tried to login a couple of days ago. I didn’t have time to mess with it then… may try again later. But I have the STL’s for both and can post them here for you in the meantime…
Neje_air-assist.zip (850.2 KB)
Enjoy! – David
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Thank you and glad to hear you’re back to enjoying your hobbies!
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Thanks! It’s a start. I just need to get out into the fresh air for a while each day and keep doing something productive… even if it’s small. I’m really losing my technical edge fast… 
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Here’s the Onshape design file for the 40W module. Silly me, I didn’t copy the centered version and mod the copy for the offset version… so only the one is shown. I’m a pretty unsophisticated Onshape designer so the workflow is pretty clumsy but if you know Onshape, hopefully, you’ll be able to figure out how to mod it for your need… – David
Thanks for this! Good to see new stuff from you!
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Thanks… and you’re all very welcome. It’s good to be back 
I’ve just published the NEJE 30W and 40W nozzle “things” out on Thingiverse. They may be a little tight fitting but a scrape here or there should make them fit… printers vary.
CAUTION: Do not try to remove/loosen the aluminum block with the laser in it. It is rigidly soldered to the circuit board above and will break the solder joints if not removed/loosened together. This is how I broke my 30W module… 
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Good to see you back. I always enjoy reading your posts. I have been working on house projects before winter & plan to get back to the laser soon. Might have to look into getting one of those 40w units. Looks like they are currently out of stock on aliexpress, but amazon has them in that link. Those 80w units look interesting using 2 lasers combined.
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Hey, Dave! I ordered the A40640 module directly from Neje. They have a US warehouse and I ordered and received the module in about 4 days or so. This is the dual diode module… total 15W optical output power.
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What safety precautions do you take when using the 40W at full power? I guess you have glasses. Are there windows to the outdoors, or other openings, in the room you’ve got the laser? Do you cover them up? What do you think about the possibility for the laser to get reflected via things via things and hit your eyes on the sides of the glasses? I’m a big wuss! I can speak in front of thousands of people, but handling these things freaks me out…
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My 2p -
I guess the simple answer is not to point the laser at anything reflective. The higher the power the more careful and vigilant you need to be.
I would also suggest the standard safety glasses supplied with the laser modules are probably not up to the task.
Neje only call their N40640 twin diode laser module an 80 watt module as a sales gimmick, it is actually a 40 Watt input module. and, as Dave says, ~15 Watts optical power
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A lot of people think that lasers should be fully enclosed, with a door kill switch. It would be bulky, but if you’re worried about it, an enclosure would relieve a lot of stress. You could wire the laser power through a microswitch that only closes when the door is closed, or use the door functionality in the firmware. Then get some kind of laser safe window to see what’s going on.
As a bonus, you could vent it through a filter or outdoors to keep nasty fumes in check as well.
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I’ve delayed offering my opinion on this matter simply because I’m probably the last guy to ask about laser safety concerns… but, now that a couple of reliable folks have spoken up, I’ll share my general feeling on the matter.
I live alone in a drafty old farmhouse, am relatively immune to the odd musty/foul smell, and have only myself to worry about when using questionable, possibly unsafe, practices, tools, and procedures. I’ve been playing with diode lasers for 5-6 years now and still have my eyesight intact. I do have glasses – cheap ones – and always use them when looking directly at the beam but don’t worry too much about reflected light. I basically act as though I’m working around someone welding nearby and/or avoiding looking directly into the sun on a bright sunny day. It probably helps that I also set up air-assist on all my lasers that consists of a conical shroud that leaves only the last few millimeters of “naked” beam exposed… similar to the “in action” photo in my post above.
So, ultimately, I guess I’ve played with my lasers enough to have grown reasonably comfortable around them… and am more concerned with starting fires than anything else. I don’t operate my lasers unattended and have glasses and a fire extinguisher nearby… and since I mostly cut wood/paper materials that are not particularly bright or reflective, most of the reflected light is just a soft blue glow on the walls and ceiling that I find oddly satisfying.
PLEASE don’t hammer me if you don’t agree with what may seem to you a rather lax attitude. I really don’t want to argue… you do what you think best and are most comfortable with. I did work with powerful lasers when I worked in industry and I like working with my lasers now… and will probably continue doing as I always have, unless and until something happens to cause me to change my ways.
Please feel free to disagree… this is just my $0.02.
– David
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Thanks for your patience with the north-pole wuss, @dart1280 , @jeffeb3 and @dkj4linux! You have given me varied enough opinions, so that I can make an informed approach based on my own considerations and precautions. I guess it’s a question of doing these things in a responsible way. A circular saw, router or an angle grinder can be just as dangerous…
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And there’s certainly few obvious perks to living on your own!! It’s incredible how loud a router can sound when being used in a cnc… I’m glad I have a sulking-shed, but sometimes that’s not enough.
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