Laser Engraving: NEJE 3 Max

The NEJE 3 Max A40640 Laser Engraver

Looking to make your own garden signs? Plant tags? Coasters? Hobby-level laser engraving machines make this all possible, and more.

Like many hobbies, however, the actual cost of getting started and realizing your creations can be significantly higher than the cost of the engraver. In this thread I’ll be covering the journey of assembling and outfitting the NEJE 3 Max laser engraver and then completing some small projects.

The NEJE 3 Max provides one of the largest engraving areas of any hobby laser, 460 x 810mm (18 x 32″) and uses a laser diode like the A40640 dual beam 10 watt module for both cutting and engraving.

Although this is a very well appointed engraver, like other diode based machines you will need to purchase accessories to make it practical and safe to use.

I purchased mine from Amazon for about $600. You can also purchase directly from NEJE.

There are other widely used diode laser engraver manufacturers at various price points, here are some examples (list prices at time of publication):

• Atomstack: A5 ($360), S10 Pro ($570), A10 Pro ($570), S20 Pro & A20 Pro ($900-$1100)
• Comgrow: Z1 ($349)
• NEJE: 3 Max ($600), 3 Pro ($359)
• Ortur: Aufero Laser 1 ($330), Aufero Laser 2 ($400), Laser Master 2 ($600), Laser Master 3 ($750)
• Sculpfin: S9 ($280), S10 ($490), S30 ($330), S30 Pro ($540)
• Twotrees: TS2, TS3, TTS-55
• Xtool (Newer to the engraver scene, but they have spent a lot on marketing, giving them a strong launch): D1 Pro ($700-$4200)

Note: Some manufacturers advertise a power (large numbers like 40W or 80W) that’s different than the optical output power (typically 5W-10W) of the laser. Optical power is what matters if you’re doing comparisons.

If you are interested in higher power and faster cutting capabilities, consider a CO2 engraver.

Caution: Laser engraving requires careful consideration for the safety of the user and visitors. Be prepared for a fire, protect your eyes from the harmful UV radiation and protect yourself from potentially toxic fumes. More info here.

UNDER CONSTRUCTION…

Unpacking

What’s in the box:

• 1 – Motherboard side rail
• 2 – Stepper motor right side rail
• 3 – Top and Bottom frame rails
• 4 – Drag chain support
• 5 – Laser Gantry X-axis frame
• 6 – Drag chaines
• 7 – Air Assist option (included as part of Amazon kit)
• 8 – M7 Relay with control wire
• 9 – USB Cable
• 10 – A406040 Laser Module, 10W dual diode
• 11 – Power Supply
• 12 – Belt Tensioner option (included as part of Amazon kit)
• 13 – Assembly brackets and hardware
• 14 – Sample engraving materials
• 15 – Safety goggles (not officially certified – professional laser glasses like these are strongly recommended to protect your eyes from UV radiation)
• 16 – TBD
• 17 – Red Door Button (this is included for use with an enclosure as a kill switch)

Items Not Included

• Waste Board – this is a board that secures the laser frame; in this case I’m using a 2′ x 4′ x 3/4″ piece of sanded plywood. This board is also necessary to ensure final square of the frame. About $30.
• Air Assist Pump – A strong air flow is required for the air assist feature to work. Air assist is used primarily during cutting operations, and a minimum of 70L/min is recommended. This is the pump that I’ve purchased for the job. About $50.
• Fume Extractor – engraving and cutting produces not only smoke, but also toxic chemicals. I’ll be operating the engraver in the garage, so I can open doors to help, but I’m still going to use this extractor to filter smoke and fumes. About $120. Note: this Comgrow extractor is probably only sufficient if you have the NEJE in an enclosure – my first tests of the engraver proved just how much smoke is generated during cuts and rasters, and the Comgrow did not even make a dent in the smoke (no enclosure). I’m considering a Vivosun grow tent with vent fan as a future option.
• Laser Glasses, as mentioned above. About $35.
• Enclosure – at this time NEJE does not offer an enclosure, so if you want one to block the laser light and reduce fumes, you’ll have to make one or purchase from a third party.
• Honeycomb Metal Mat – provides heat dissipation and air flow during cutting operations, I purchased this one for about $160.
• Fire extinguisher and fire blanket. About $50

As you can see, there’s more to getting started than just purchasing the diode laser engraver. Note that CO2 machines cost more, but also tend to include more of the listed options as standard.

NEJE gets kudos for providing good build quality and:

• An air assist valve, control and associated laser module nozzle
• Drag chains for wire management
• A precision Z-axis adjustable mount for the laser module
• Belt tensioners

And some cons (all of these are addressed in this blog):

• Instructions (what instructions?)
• Squaring the rail assembly is critical, but poorly documented
• The Z-axis (H2O) slider is not designed for the A40640 module
• NEJE doesn’t offer an enclosure, and after doing a trial engraving I can say you need to have an enclosure to contain the smoke and fumes (or an extremely good exhaust system, or both)
• You need a very good exhaust system, even with an enclosure, and because of the size of the 3 Max the enclosure and exhaust need to be top notch
• NEJE provides an air assist solenoid and laser module fitting, but no pump. The provided accessories require a very strong air pressure, so you need a good pump or compressor. Also, the laser module fitting is finicky and makes it difficult to access the laser lens for cleaning.

Assembly

Side and Top Rails, Metal Drag Chain Support, and X-axis Laser Gantry

Layout the rails, placing the side rail with motherboard on the left.

• Secure the side and top rail corners using the M5-10 socket bolts.

Check to make sure that the frame is square. This is a large frame, and even a small error can be significant, so make sure the frame is square after each frame assembly step.

Attach metal drag chain support (1 of 3)

• Use an L-bracket to secure the right side to the Motor Y-R assembly with two M3-10 bolts & nuts.

Attach metal drag chain support (2 of 3)

• On the left side, remove the two black zip ties that secure the cables (the holes will be used to secure a bracket).
• Secure an L-bracket and the drag-chain bracket using two M3-10 bolts and nuts.

Attach metal drag chain support (3 of 3)

• Secure the drag-chain support bar with the lower base facing the back of the machine with M3-10 flat head screws & nuts
• Before tightening all of the screws, pull the stepper motors to the front (bottom) rail and confirm that the assembly is parallel to the rail (both stepper motors should be touching the rail).
• Do a final tighten on all screws and bolts.

Status pic – here’s how the assembly appears at this point:

Remove the connector from the Laser module stepper motor and the two zip ties holding the cable in place.

Route the Laser module cable through the hole the left side drag chain bracket, then through a drag chain.

Fish the air assist hose through the drag chain (not shown).

Attach the drag chain at the middle of the support using two M3-10 bolts and nuts.

Attach the Laser Gantry X-axis frame with two M5-10 bolts.

Insert the Motor Y-R connectors at the stepper motor and at the motherboard.

Attach the second angle bracket to the laser module stepper motor with two M3-10 bolts and nuts.

Attach the other end of the drag chain to the angle bracket using two M3-10 bolts and nuts.

Feed the red laser module wire and air tubing through the angle bracket hole.

Attach the laser stepper motor connector.

Status pic – here is what the machine looks like at this point of assembly.

Attach the air assist solenoid to the angle bracket using the provided screws.

Mounting to the Waste Board and Final Square

The NEJE 3 Max has a very large working area, and even though the extruded frame is rigid, chances are at this point it is slightly out of square. And for an engraver that measures accuracy in fractions of a millimeter, a rigid and square frame is critical.

Here are the steps that I used to mount and square the frame:

Position the frame where you’d like it on the waste board. Since I’m using a high quality piece of plywood with factory cut edges, I used the front edge of the board as a reference, and spaced the left and right front corners of the frame equally away from the edge.

Attach the front left corner, then the front right corner using the supplied brackets and screws.

Pull the laser gantry all the way to the front of the frame and let go – both the left and right stepper motors should touch.

Make adjustments as needed by placing left or right pressure at the back of the frame until the laser gantry is parallel with the front of the frame.

Now secure the back two corners of the frame to the waste board, double-checking square as you go.

Fish the USB, power, red door switch and relay control wires through the second drag chain. I ran the USB through first, then taped the ends of the remaining three wires together for the final fishing.

Mount one end of the drag chain to the solenoid bracket. This is an area that needs improvement by NEJE – the mounting holes are not spaced properly for the drag chain, and the screws that affix the solenoid prevent the drag chain from mounting flat. Patience is a virtue 🙂

Screw the other end of the drag chain to the waste board.

Connect the red button to the Door input, the relay control wire to M7 and the air assist solenoid to M8.

Plug in the USB and power cables.

Connect the red cable to the laser module, then attach the module to the Z-axis adjustment bracket.

We’ll discuss the test patterns shown in this photo later. First the laser focal length has to be determined…

But before we do any cutting or engraving, let’s look at a suitable enclosure and exhaust system. All it took was one run of the laser and it was clear that smoke and fumes would have to be dealt with.

This is a 4’x4′ Visosun grow tent with AC Infinity 6″ exhaust fan and carbon filter. 25′ of flexible 6″ ducting allows me to vent out a door.

This setup takes up 16 sq feet of floor space, but the tent can be moved when not in use and provides a mini-workshop. Down the road I plan to add a Lightburn camera above the work surface and needless to say, there is plenty of room 🙂

The Ramp Test

The A40640 laser module has variable focus, which, for the novice, is a bit of a detriment, because you need to select a focus for the lens, and then an optimal distance to the work piece.

Based on a video from the LA Hobby Guy, I elected to screw the lens all the way in; NEJE mentions screwing out the lens a few turns, so you’ll have to pick a point to start. Watch Rich’s video linked above to learn the details of the ramp test.

In the previous image you can almost see the yellow lines that highlight how the work piece is ramped on the honeycomb surface 😉

Since the laser module travels at a constant distance from the table, the ramp reproduces a range of module to work piece gaps. Somewhere along this continuum you can find a sweet spot where, even at very low power the laser is focused enough to leave a mark on the wood.

For my 3 Max, 22 mm from the base of the laser module heat sink to the work piece proved to be best.

To further test the focus I created a jig to establish gaps of 24mm – 19mm from the laser heat sink to the work piece.

21mm provided the best performance, but 22mm and 23mm were very close (see next figure).

For cuts you should focus the laser at a point half way into the thickness of your work piece. In this case the wood measures 3.2mm, so we could say the focal point of the laser is 22.6mm from the laser heat sink.

All of these cuts were performed at 360mm/min and 2 passes; ignore the engraved text 🙂

Looking at the back of the wood, 22mm and 23mm were very close to the winning gap of 21mm.

Note: These cuts were made without air assist (still working on a practical installation of the air assist feature.)

Coming Next:

• Adjusting the laser module focus ring
• Mounting the laser
• Adjusting and verifying focus

• Running a universal test card to confirm performance

Supporting Videos

• Buster Beagle 3D NEJE 3 Max Assembly Instructions
• LA Hobby Guy Is this the best new Diode Laser, Engraver, Cutter in 2022?