Laser - J Tech Photonics Tips and hints

I fired up my new 2.8W laser for the first time today. I used the PicLaser demo to see how things would work and I made some smoke and burnt in part of a photo (demo limitations). I changed the extension to .g and ran it from a SD card and it ran well.

@alan - What software did you use to create your part? I am not having any luck with the InkScape extension as it is giving me script errors.

Ryan - If you don’t like the idea of a dedicated thread please delete this.


I like the idea of having a single thread dedicated to lasers, particularly the JTechPhotonics, which most people seem to be using. I ordered mine on Christmas eve. I expect I’ll see it sometime next week. It has to come from Houston all the way to Austin LOL. I will repost my questions from the previous thread, since they haven’t been answered yet, and this thread is where people will probably look for them.

How do I get started generating code to drive the laser? Ryan mentioned using ESTLCAM, which I use for carving already. Do I need to modify the resulting gcode to make it work with the laser? Also, do I need to make changes to Marlin to incorporate the laser? Does the laser come with a wiring diagram of how to connect it to the ramps for control?

Curt - what is the inkscape extension you mentioned? I use inkscape, though I usually export to DXF and then bring that in to ESTLCAM for carving. What does the extension do?


There is a lot of helpful information on the jtechphotinics website. Under product details there is a documents section and under the software section there is a page just for the Inkscape plugin and for the PicLaser program license (which I ordered today). I assume you ordered the same kit I ordered. Did you order the laser fan upgrade? I did not since I had a fan and I can print the mount. The only issue I had was the jst plug needed to connect it to the control board. Since your kit will not ship until Jan 4 (per the website) you might want to add to you order.

The extension will create the gcode right from InkScape…or at least that is what it is supposed to do. I think I found my issues and I hope to try tomorrow.

I would like to know the software and such that Alan used so I hope to hear from him soon.

Darn it, looks like you’re right, Curt. I hadn’t seen the message on the website that new orders will ship after 1/4/16. Not a big deal, though. There’s plenty to learn - I’ll take a look at the resources you mentioned. In addition to the new laser, I’m also almost done with my new foam cutter, and still need to learn how to use it, as well.

What kind of stuff are you planning to do with your laser, Curt? Lasing pictures looks interesting. Are there any resources similar to thingiverse for laser cut projects?

Just to chime in.

I haven’t found the JTECH plugin to work. It’s written (I believe) specifically to work with their JTECH GRBL firmware, which we don’t have. I’ve been planning to look more into the GRBL on Ramps thing that another forum user tested out, but I haven’t had the time.

I’m also considering temporarily borrowing the Arduino/GRBL shield from my XCarve and playing around with that until I can get another setup for GRBL.

Right now, I’m using Easel from Inventables. The limitation is that it doesn’t do lasers, so I have to edit the resulting Gcode files and use M106 in place of Z down movements and M107 in place of Z up (presuming I’m just etching).

It’s not perfect, but seems to work.

First off, I wasn’t sure if we were putting everything laser-related in this thread or if I should start a new one for my question. If so, I apologize.

I got the laser and driver wired up, but I cannot get it to beam anything. Here’s the steps I’ve taken:

  1. Wired H2 (+/-) to D9 (+/-) on the RAMPS board
  2. Checked to make sure that H1 amperage is set at 1.00 A
  3. Plug in laser to H3
  4. Set switch to “CW”
  5. Turned key on and flipped the switch.

I get the “Enable” and “ON” lights to light up, and I know that the driver is supplying 1A, so I doubt that the driver is at fault here.

Is there anything obvious that I am missing, or could the diode possibly be defective?

You need to use M106 S to turn on the laser(or fan output). The use M107 to turn it off. Download the pic laser software and try the demo.
Did you get it to turn run on to focus the lense?

I have tried running gcode with M106 SXXX to enable the laser, and it does not turn on.
No, I have not been able to focus the lens yet. I had set it in CW mode (Continuous Wave) so that the laser is always on, but still no output.

I would email the guys at JTech and see what they say. I just tried mine again and with the switch and key on and after hitting the reset my fan starts up. If I flip the switch to CW my laser starts up.
Sorry I am not more help

I emailed Jay from JTech with the same details that I provided earlier. He is actually sending me a 2.8W (upgraded from 2.0W) replacement free of charge.
Great customer service there!

I received my 2.8w laser kit yesterday, and have started working on mounting it and setting it up. I have a few questions:

  1. Where are people mounting the driver? Should it be mounted on the z tower somewhere, close to the laser, or should I extend the wires and mount the driver somewhere else, like near my ramps LCD?
  2. Where do I connect on the ramps board?
  3. Can I use the piclaser software with this setup (ramps + marlin), or do I need the DAC/PWM board advertised on JTP’s site?

Any help is greatly appreciated!


I used long wires and have my laser driver over with the Ramps board.

Here’s the link from Jtech on hooking it up to a Ramps:

For the short answer: hook it up to D9.

I think the piclaser programs are all based on GRBL, so I’m not 100% sure it will work. For Ramps, we’re using M106/M107 to turn an unused “fan” on and off. In their GRBL based configurations, they have it set to the PWM control for a normal spindle (M05 I think?) so I don’t think it would turn on and properly change the laser intensity.

Another user here linked to the Amazon pieces to put together a second Arduino with a GRBL based CNC controller…I think the whole thing could be done around $50-75.

He’s also tested a little of the GRBL for Ramps github release for the Arduino. I had trouble trying to compile/upload it so I gave up for a while. May try it again.

Similar to Alan, I have my J Tech driver near my LCD (I have not figured out a good mount for it yet on the Minion case). I used an old plug set from a R/C receiver battery to allow me to disconnect the J Tech driver from my ramps board as needed.
The piclaser works fine with the setup from Vicious. You do not need to buy any more hardware. There are some good videos linked to the J Tech site to walk you through the set up but basically (like Alan stated) you will use the M106 S and M107 commands when connected to the D9 terminals. I bought the license for PicLaser and I am planning on buying the laser etch software also. Test both demos first but know that they limit the size of image in the demo but will show you what they can do.
I have been working on a remodel project in the house so I have not been able to play much with the CNC.

What height are you setting your laser focus at?

Good to know. Maybe a specific thread for how to set up the PicEngrave and other software would be helpful?

I’ve tried the demo and as soon as I get something generated the Repetier-host time shows something like 7 hours, and I just don’t have that kind of time or faith in leaving my laser running for that much time.

Got any pics from your piclaser projects? Would love to see how they’re turning out for everyone.

I think I set it at something like 1.25" based on what they mentioned in their install/focusing docs.

I have trouble finding what I consider the “sweet” smallest laser spot. I’ve also been experimenting quite a bit with adding things under my wasteboard and changing the material heights, that I haven’t found a good way to 100% ensure consistency.

Eventually, I’ll look into building some sort of electronic touch plate…or even just something basic that I can fit as a “dry” gauge to get reasonably close. Right now I’m using my wife’s plastic ruler which is unscientific at best.

What I’d really LIKE to do is create a file like the Epliog’s raster burn tests that use different speeds and laser intensities to see what each burn looks like (for vector burns). I’d like to do the same thing with Z heights so I can calibrate it with real burns instead of just trying to see how cute the little dot looks with the laser turned way down.

I managed to draw a few rectangle outlines with Easel that each burn at a different intensity. (IE: M106 S255, S200, S150, S100, S50). I then copied the file a few times and edited the feed speeds so I have a single file of ~5 rectangles for each speed (50mm/m, 100m/m, 200mm/m, 280mm/m, etc) to try and see what produced the cleanest lines at each speed and intensity.

But, I didn’t spend the time to line up each rectangle nice and straight, and then you have to run the file for each speed since I edited only the feed rates and not object positions, so you have to reset your zeros and try again.

I’d like to do the same thing, but also with Z depth/speed/intensity, though that would probably take up at least a full 12x12" sheet of material! :slight_smile:

At least once that is done, I’d have some fairly accurate results for my material and could (hopefully) manage to find the perfect settings for all 3 and could then make some sort of height adjust to ensure it’s perfect every time.

I like routers better, you just touch the bit to the material and it’s ready to go. A lot less guess work when the tool properly touches material.

Thanks everyone, for your insights and answers.

I’m actually working on a mount to put the driver just above the laser, using HicWic’s universal mounting system, but I might end up not using it, depending on some of the other wiring. Speaking of which:

I think I saw that there is a place to connect the laser cooling fan on the driver board - is that correct?

I also have two line lasers, to create a target for positioning the big laser - is there a place on the driver I could get power for them, as well?

Thanks again!

I’d be wary of putting it right above the laser, for a few reason.

  1. Heat rises. No need to put electronics right on top of a hot laser. Though, did you buy the additional fan to use a “semi-air-assist” to blow smoke down and away from the laser? That might move most of the heat away too. I’m about to hook mine up tonight or tomorrow (just came in the mail) and will see how hot it gets just above that fan. I imagine not much if the fan is blowing down towards the workpiece.

  2. Z stability. This is pretty stable, but I always worry about it. Are you also going to use a router or printer head on it? How would you get the laser driver off and unplugged to do a tool change? I’m happy that the laser is nice and light and doesn’t cut laterally on the surface to create twisting tension…but I wouldn’t add a fraction of an ounce to the Z axis just out of pure OCD about that kind of stuff. Particularly since there’s not a whole lot of easy ways to adjust Z straightness outside of the tool mounts.

I’ve read about adding the fan to whatever power the driver fan is on, but haven’t checked it out. That’s my “plan” for researching today.

The pic on the JTech site I think assumes a real “power supply” source other than the laptop style plug that I got here. They have additional fans and LEDs plugged into that. If you’re using a more dedicated power supply like that, I’d think having it on there would ensure not drawing too much power from the driver board (I’m not an electrician, so I know nothing of this, just speculation).

The fan for removing the laser smoke can be driven from the laser driver board. J Tech sells a kit with the fan and wiring but they offer the stl for the fan mount so you can use a fan you already have. I chose this option but I did not have the plug that fit the port on the driver board so I ended up ordering the plug from J Tech and it should be in the mail box today. The fan can be powered from any 12 volt source (which is what I had to do temporarily).

I am going to use my CNC for some lasing and some routing so I do not want the laser or laser driver covered in dust so I will remove and store it when routing.

I will start a PicLaser/Laser Etch thread soon and start sharing some info there.

I think that is the recommended height but if you watch any of the videos on their site, the setups they have are MUCH higher than 1.5". Talking to one of my guys who is a laser expert (used to work for one the big industrial laser supplier) and he encouraged me to be as close to the part as possible to minimize the losses due to the beam hitting anything in the air. I have mine set up at about 2" now but I will likely lower it when I come up with a good height tool (spacer block) to allow for easy setup.