2.5W ELEKS Module Replacement?

[LaserJack]

Greetings and Happy New Year LaserFans,

I am relatively new to the forum, but have already communicated with Zax, BCL about other topics. I have a 2500mw A3 eleks maker Chinese toy. Over the holidays myself and two others worked out a lot of frustration trying to get this system to consistently work. The colleagues are well experienced with electronics and mechanics. They optimized the frame pullies and tweaked what they could to insure stable movement of the X and Y motors. Then made many tests with all the options of speed, time, focus, trying to burn on simple card stock (180g) black. The 2.5W laser module delivered inconsistent results, sometimes cutting and sometimes not all in the same project. The module was checked closely and revealed that the mini fan was not sufficient as cooling, so they used an airbrush to cool it while operating, also the current draw was only 1.4AMP, not >2A advertised. We used T2Laser and BCL and Benbox software while also using Inkscape, QCAD, Fusion 360, and just the plain old GCode translator (GîtHub). We used 0.9j all the time.
Now we see that the shitty module works on start up, then dissipates in power and is useless.

Our BIG question is: what would anyone recommend to replace this laser module with a (non-Chinese) module? I remember Zax writing that the 5.5W cannot focus the beam to a small dot. BUT, this is likely the Chinese ELEKS version. We also realize that we may have to purchase a module that requires re-drilling to fit on the gantry holder. We also wonder at the power of the stepper motors, if they could correctly move a larger module, like a 7W, 10W or so? Finally, we do not recommend anyone starting with these laser toys. Lost a lot of time, some money (cost us an extra $60.00 import duties here in Switzerland). THANKS FOR YOUR FEEDBACK!!!

Jerry Jackson, Bern, Switzerland

[Administrator]

I stopped using the 2.5w unit for over heating reasons...I went with a 1.6w and it runs very cool on long cut jobs and has a very small focus dot...I need about 2 more passes to cut with it, but overall I'm very pleased with it.

[Zax]

I replaced the original 2.5W with a TTL 2W and it has the same power and much more control. It also has a larger heatsink and better fan, and runs with no increase in temperature.

[echo4golf]

Zax,

Do you have a source for the 2W?

Thanks,
Jerry

[Zax]

You can find others (aliexpress, ebay etc) but these are the TTL lasers that Banggood currently has:
http://benboxlaser.us/index.php/topic,1355.msg16446.html#msg16446

[echo4golf]

Thanks Zax.  I'm looking at the 2W in hopes that it will be a bit more controllable than the 2.5 that came with my GearBest unit.  I have been disappointed with the quality of grayscale projects thus far. Even with dithering it's a bit problematic.  I've been wondering if the lens is messed up but haven't gotten so far as to disassemble the little beastie yet.

Jerry

[Zax]

The 2W is excellent, very precise focusing and it's output is equal to the 2.5W but the biggest improvement is the power control from 1 to 255 in linear steps. It does require adding length to the wiring but connection is very easy.

[QuietMike]

So these ttl lasers are actually linear in power, - 100 is actually half the power of 200?
How do they retrofit to the existing wireing?

[Zax]

I didn't check the actual output, but visually it appears linear. The problem is that doesn't mean linear results, different materials act differently.

Wiring is simple, check the threads on the connection.

[QuietMike]

so what is TTL, and why is it better

[ggallant571]

On a typical laser controller board the CPU generates a PWM pulse train the turns on a power transistor (MOSFET) that switches the 12V power source. The signal is wired to the diode module where it is turned into a signal appropriate for controlling the laser diode.

On a TTL configuration the MOSFET on the controller board is bypassed and the CPU signal (TTL level) is wired to the laser diode module along with the raw 12V power. The control module then converts this to the appropriate diode control signal.

Which is better is can be very elusive. I suspect the electronics on the laser module are the significant factor. It appears that some contain components that change the ON/OFF switching pattern. These circuits may improve the laser performance while cutting at the expense of quick switching desired for etching.

It is my opinion that the MOSFET driver circuit on the Eleks controllers is pure crap. Marginal at best. Perhaps the "TTL" circuits compensate for this deficiency by reliably performing the switching operation. In the end, a TTL logic level needs to be translated into a high power diode current.

BTW, I built my own controller with a dedicated MOSFET driver and have been getting quite nice etchings.

[HaniC]

Lasers generally need constant current control. I would suspect the ttl laser driver takes an on/off style PWM signal input and instead of switching the driver on and off actually controls the current to the laser diode in a more linear analogue way.

[LaserJack]

Here is a site I have been looking at: http://odicforce.com/  They are UK based. So prices are in GBPounds.

Look at their section titled: Projects and Applications  there are a couple of seemingly good articles which may help the entire benboxlaser forum. Been looking at the 450nm Blue Focusing Laser Module (12V) TTL Driver module. Paying in British Pounds costs me more. 99£ is 124.00 CHf. Plus comes the customs on top, so I will be near 175 Swiss Francs for a 2W module. A bit too much. I also see a large selection on Aliexpress, BUT I really do not want to invest in another laser head from China. The ODICFORCE company state that every laser they sell is in-house tested. The other advantage is OdicForce sells module kits and accessories so you can build a head yourself. I like the Component Bundle for Current and Voltage kit No. OFL520, to be able to monitor current and voltage. They also sell a 3.5W and 4W but clearly state in their article "Laser Modules for Cutting/Engraving (CNC)" that testing shows faster cutting, less passes, but do NOT give any significant increase in thichness of materials that can be cut. THAT is the info I think we all want - module reviews by competent engineers!  And here are the reviews from AliExpress:  https://www.aliexpress.com/blue-laser-module_reviews.html   But as I read AliExpress and Banggood sell Chinese laser modules. So, I am still undecided. More later . . . .

[ROSS]

 ..............and by the prices on the UK site they are similar to the Chinese dealers......
However, you may get more sense out of the UK dealer if you have a query tho!!

[vernerl]

What is interesting I am also "happy" 2.5W banggood laser owner. I hope when my TTL board arrives, I post some images how to prepare and connect this laser to TTL. At this moment I cant find information what laser type for 2,5W is inside black aluminium case. Nobody in the world does not produce laser diodes with such parameters. There is maybe 1,6--2W or 3--3,5W laser, who knows.
Here I found good vision, how to prepare 2,5W laser for TTL.
All what we can do very well with not TTL 2,5W is make nice outline type drawings, cut some cardbords, cut opaque acryls
AND ALSO!!  (many thanks Zax for information) 
we can make grayscale similar drawings. How to do it here.