Inventables Community Forum

15w laser upgrade questions

I am considering using the xcontroller spindle output to control the laser on and off function. I would include a master “off switch” to interrupt the power to the diode for emergency situations. After looking at the prices on the jtech laser, I find it hard not to look at other options. I am looking to engrave 1/4" dark acrylic, either black or smoked gray. Just a company logo and nothing with super super fine detail, just a logo with company name. What considerations about this laser and using the xcontroller may I be overlooking or need to consider?

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If you look on google you can get a whole machine with that laser head for around the same price if I can locate it I will send a link. I think it is on ali express It is a small machine but could easily be made larger.

Be careful with these. 15watts is way different than 1.5watts.
I have found that some remove the decimal and you are mislead.
Make sure you find the original manufacture to get the data sheets.
I could not find them for the listing but it appears to be legitimate.

9khz is what this one runs at for the PWM. The arduino can handle this.

I used to run a epilog laser and have owned a Full Sprectrum laser about 2 years ago.

Wow check this one out!
http://www.ebay.com/bhp/40w-laser

complete system and cheaper than the module.
The only thing about CO2 lasers are the tubes. If they are made outside of the US then they are junk and will not last very long. If you have standard size/hookups then you can order a USA Made one that will work way better. Just add 200 dollars more if that is the case.
Also the electronics are important. I had one laser system that could not do any decent engraving No matter what I tried. Spent 3 weeks then returned it. I got tired of trying to make it work when it should have been tested and working when I got it. I can understand if it was a tube that came broken or a belt misaligned. But it was the electronics. The company didn’t want me to sending it back. They charged me 500 dollars for restocking fees too. :confused:
I learned a lot from what little I did with it.
I hope you guys can locate a decent module cause I want to do the same. :smiley:

What I was hoping to do was to remove a dust cap from the laser diode, engrave a bunch of company logo’s on a 2ftx4ft sheet of acrylic, put the dust cap back on, and then cut out all of the parts as a semi seamless interaction. Thus having the laser on the cnc would be ideal and a Co2 laser is just way more than I need. I say acrylic but it will actually be polycarbonate so laser may be out of the question as the more research I do on polycarbonate, the more laser looks to be a no go.

This is my first CNC machine and already know that I will be using it to build a larger 5ftx10ft machine as my needs grow. If my ideas never take off then I have a fun hobby toy to dink around with, if they do take off then I will need something that I can run full sheets of plastics through as well as cabinet grade plywood. I have been in the aquatics industry for some time and make my items by hand, so a CNC is a logical next step into speeding up production with much more precision and duplication.

Some plastics create toxic fumes so PC may be out on the laser as you said.

Cutting polycarbonate with a CO2 laser works, but the edges of the cut are charred and smell horrible. Even with an enclosure and ventilation it stunk up the room. Separating the parts leaves an oily smelly residue on you hands, though it is easily cleaned up with soap and water.

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I purchased a similar 15W laser from AliExpress (https://www.aliexpress.com/item/High-Power-Diode-Laser-15W-15000mW-Focusable-Blue-Laser-Module-450-445nm-with-TTL-Driver-for/32757380573.html?spm=2114.13010608.0.0.03ASzf) with TTL input control.

The X-Controller’s PWM output is doing nothing to the laser via the TTL input. The laser won’t turn on at all. If I provide 5V directly to the TTL input the laser lights up, so I know the LED is okay and the controller board has some functionality.

I suspect the PWM frequency of the X-Controller (stated elsewhere on this board as 7.819kHz,) is incorrect. The JTech laser for X-Carve is described as 1kHz (OK, what's the solution for PWM to a laser?). I see 9kHz described above.

There is some discussion of how to change GRBL’s PWM frequency here: https://www.shapeoko.com/forum/viewtopic.php?t=8372&p=65246 but I’d love to have a better theory of what to change it to if anyone has a good guess. I’ve messaged the seller, but am skeptical about the likelihood of a useful reply.

Thanks,
–tim

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TTL logic is on/off. You have to have an appropriate laser controller to modulate the current to the laser.

You can use your laser with on/off control by using an S word value that is sufficiently high to cause the PWM signal to be 100 percent duty cycle to cause a TTL high signal.

What that speed value is, is dependent on the version of grbl you are running.

For 1.0c, if you have $31 set to 0. and $30 set to 1. (note the decimal point) then M3 S1 (or any value larger than 1) would turn the laser on, and M5 or S0 would turn the laser off.

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LarryM,
Thank you, I am using the controller provided with the laser to modulate the power to the laser with the PWM signal from the X-Controller. The TTL input available on the laser controller should be allowing me to duty cycle the laser for effective current modulation.

My primary issue was user error in that, when wiring the TTL plug I used the wrong side of the provided plug cable (which I’d cut in half,) and wired the TTL polarity backward. Having fixed that, the PWM signal is now able to turn the laser on and off via M3 and M5 commands.

The S value is not managing to provide a variable level of output. S1200 and S18000 both provide the same (apparent) power level. M3 S0 provides no power, so I am getting a response to the command. Even M3 S1 turns the laser (as best as I can observe,) fully on.

If I’m providing an inappropriate frequency to the controller (especially if it’s expecting 1kHz like the JTech and I’m providing 7.819kHz,) it’s not unreasonable that I’m getting the response I see. I’ll probably build myself a little arduino variable frequency PWM rig and see if I can find the sweet spot before whacking at the GRBL.

Thanks!
–t

@TimDeagan

Try this instead:

https://discuss.inventables.com/t/xcarve-jtech-grbl-update-11-12-2016/28943

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Sweet, thanks! I’m currently on [1.0c.20161011:] so that should be a big help.
–t

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LarryM, thanks to a note you made downthread in the other thread you pointed me at, I noticed that my current $30 was set to 1. Changing it to $30=18000 makes the current setup work as intended!!!

I’ll still change to the JTech fork but knowing that the rig works is wonderful! I have a full set of 3D models printed for mounting the 15W laser and I’ll be posting them.

Thanks again!
–t

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The mounts for the 15w laser, controller and power supply that I published are now up on Thingiverse: http://www.thingiverse.com/thing:2172609

can you engrave on metal with your 15w? the ali express link says it can’t, but the ones on eBay say it does, there’s some videos that show it working on stainless. just want to be sure before I purchase one

When engraving metal with a laser you need to look at the wavelength of the laser more than the power. Each metal reflects different wavelengths of light better than others. How much energy it takes to etch the metal will depend on the reflectivity of your wavelength and how fast the metal dissipates heat.

I was curious about using a hobby grade CO2 laser to etch circuit boards, but it’s next to impossible at that wavelength. I had access to a 50W Epilog laser. With the power set to 100% and travel to 1% the laser left no discernable marks on a 1/2 oz copper board. After testing I looked up the reflectivity of copper to 10,600 nm light and it was nearly 100%.

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I can kinda-sorta engrave metal with the 15W. If I coat the metal with a black permanent marker or somesuch, I’ve been able to do light engraving on steel. I suspect I could improve it with multiple passes.

I do have one of the K40 China Lasers, and Drymoly will also have some success. It doesn’t really engrave as much as just burns a darn near hard to get off coating.

Hi ,
I’m also planing to buy the “High Power Diode Laser 15W/15000mW” from AliExpress and use it on my CNC with GRBL shield. I can’t find too much about this laser diode and the description is generic one, the seller used same description for different models.
Is it possible to cut felt 1mm thick? How about a soft plywood 4mm? what is the speed and what’s the quality of the cut? If anyone has videos with this module cutting different materials please help.
Cheers

Take note that this diode cannot deliver a continuous 15 watts. It can attain 15 watts for brief periods with sufficient cool down times between pulses.

Most of these diodes are capable of around 5 - 6 watts continuous.