Looks impressive for the money ?

So I'm looking at hooking one of these lasers onto my 1040 cnc.

Says it can cut ply single pass 8mm was skeptical but then saw someone demo it on YT

I think at that price I will take a punt , really mostly doing some etching for my daughters Etsy wooden stuff. And a few ply coasters for a friend. Anyway I'll let you know how it goes.

Attachment 29339

Specs

30W General Specification:
Model：NEJE Module 30W
Heatsink Material：Aircraft Aluminum + Brass Shell
Luminous Color：Blue
Section Size：40mm x 40mm
Cooling Mode：Temperature sensor intelligent control + 10000 rpm 40mm cooling fan
Dimension：60 * 40 * 40mm
Adapter Plug：5.5 2.1 port
Can Engrave：MDF/Balsa/Paper/Wood/Fabric/Plastic/Leather/Plywood/Foam Paper/Anodized Aluminum
Can Not Engrave：Metal/Glass/Stone/Ceramics/PCB/Stainless Steel/Reflective Material/ Transparent Material
Technical Parameters：
Module Input：20-30W
Optical power output：7.5W (7500mW)
Wavelength：445-450nm
Beam Shape：Dot (Focusable)
Working Voltage：DC 12V
TTL&PWM Modulation：YES, Compatible with Both TTL & PWM Modulation
Input Voltage：DC12V 3A
PWM/TTL Input：DC3.3V-12V
Input Interface：PH2.0-4Pin (+,-, PWM/TTL, Temperature), 3Pin (+,-, PWM/TTL) , 2Pin+2Pin (+,-) + (PWM/TTL,-)
NOTE：Temperature interface can be disconnected，NEJE provides text instructions for temperature acquisition on wiki.
Drive Mode：External ACC
Safe temperature range：<60 ℃
Module weight：202g ( The lighter the weight, the smaller the move inertia, the better the performance )
Life Time：10000-20,000 hours

Watching with interest. I'm not quite flush enough to punt £130 on a whim, but it you report good things then it's a good option.

Can I advise - get a thin sheet of ali to sit on the bed of your CNC - various materials cut tend to leach either resins or chemicals, which can mark the bed.

I'd personally not put a sheet of ali under an unenclosed laser. I'd put down a sheet of something sacrificial that'll absorb the laser, not reflect it around!


One thing you'll want to add is a small fan to blow fumes away. It doesn't have to be strong, just enough airflow so the smoke/fumes aren't able to rise straight back up and coat/obscure the laser lens.

Quote:

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Originally Posted by m_c

I'd put down a sheet of something sacrificial that'll absorb the laser, not reflect it around!

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Then keep a fire extinguisher handy :)

You'll lose coherency on anything other than a polished surface, the amount of energy reflected back into the LED - there'll be some, but not a huge amount. Air assist and extraction all good ideas of course.

I'm actually excited to have a go, the CNC has been in packing boxes for the last 18 months. But now I have my new home office big enough to get it built in, I'm going to do "stuff" lol
I'm on CAD atm working out a stand and enclosure to hand over to the smithy to make. Only problem is, hes use to making agricultural machinery so it will be made with battleship armor. I'll have to get some photos of some of the stuff he makes.. seriously over engineered lol

I have an idea for a low pressure cyclone air filtration system. I saw one at a factory I visited last year and it worked really well.
As for fire, I have a plan for that already.

So just to bring this up to date.
It looks like these lasers only work with NEJE's own controllers.
Which they don't state on the sales page on AliExpress or Amazon for that matter.
They are simply an upgrade.
Waste of $100.. be aware of this.

I thought (only 5 minutes casual googling) that the laser was controlled either by a TTL or PWM signal? But I'm struggling to find the spec of the PWM signal (frequency, and active level, 0%/100% reference pulse widths)

What are you driving the PWM from? (e.g. a PWM output from a BoB?) In which case there may be a general sensitivity to the PWM frequency (and you might need a mini interface to take PWM of one frequency, and re-present that at another). That's all do-able and a cheap ardi (that you already have) could be brought to bear to achieve that.

Any documentation with the laser?

Deleted post - not convinced that the laser module isn't just driven by TTL-signal from the missing PWM controller. (ignore image that I can't figure out how to remove)

I understand

It's hard to assess performance and operation from a web-based forum. That you can test-fire the laser fire suggests a constant demand generates full optical power (and absence is off), and that suggests the laser diode itself is "working" (and for the supplier, that's probably the position they're aligned to). The only question I would have is the operation of the control circuit built into the laser assy - that allows the diode to be modulated with the TTL input. It **should** be a case that "on" is lase, "off" is don't-lase, and that is simply and exactly what an Arduino PWM output will produce. If the laser assy is questionable, then that can be assessed with passing a variety of signals into the laser and observing the resulting laser output. Similarly, you should be able (with equipment) to monitor the PWM output from the Arduino, that under GRBL it generates a pulse with variable mark-space ratio up to full-on (or near-as-dammit). Without testing these it's difficult to throw blame at either the laser or the arduino/GRBL.