How to Add a Laser Engraver to Your 3D Printer

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Introduction: How to Add a Laser Engraver to Your 3D Printer

I wanted to laser engrave a clock face for a magnetic clock I am building, but didn't want to invest in a laser engraver without knowing how much I would use it. Also the clock face is larger than most laser engravers allow. I have a CR-10 3D printer, which can be driven as a laser engraver, and has a 300x300mm workspace. I just needed to figure out how to mount and drive the laser on the CR-10.

After some research, I discovered you can drive most diode laser engravers from the PWM output of the part cooling fan. However, you can't just use the fan wires already connecting the printer control board to the cooling fan. You will need to power the laser separately and connect the laser PWM to the 5 volt input of the fan control MOSFET for it to work.

Supplies:

    To connect the laser engraver to the printer you will need:

    To build a laser shield:

    Step 1: Connect the Laser to the Power Supply

    This will be specific to your printer. You will need to open the control box (plenty of videos on Youtube for various printers) and add connections for +12v and ground. If you have an Ender 24 volt printer, you can see how to add a 12 volt circuit here. You will need to route the power and ground to a connector near the hot end. I'm assuming that if you have the skills to attempt this project you are capable of routing the wire from the PSU to the hotend. Remember to turn the power off and unplug the printer.

    Step 2: Connect the Laser PWM to the Cooling Fan MOSFET

    This should work for all Creality boards and likely many others. Solder a wire to the exposed 5V part cooling fan control pin as shown. I've used this on the original CR-10 board, V1.1.5 and V2.2.1. Be sure to connect a 100 ohm current limiting resistor between the MOSFET and the laser. This will simulate the load of the cooling fan and protect the board. Also route this wire to your connector at the hotend.

    Step 3: Connect the Laser

    I wanted a sturdy, locking connector to be sure the laser stayed connected. I chose this connector

    I cut one of the JST connectors off the end of the laser cable, and replaced it. I connected the matching connector to the wiring from the printer.

    Alternately, you can cut one end of the laser cable and wire directly from the printer to the laser cable. I chose not to because I wanted to connect/disconnect the laser farther from the hotend.

    Make the connections as shown in the picture. If you have a fourth wire, it's for laser temp and you can leave it unconnected.

    Step 4: Print and Assemble the Laser Mount

    The easiest way to mount the laser is to 3D print one of the files below and attach the magnets. This will hold the laser in place and work well. I have included both a side and top mount to choose from. Use the M3 x 10mm screws to connect the pot magnets to the mount and the M3 x 30mm screws to screw the mount to the laser just under the connector as shown. The laser will then ride solidly on the hotend of the printer.

    The mounting will reduce the Y-Axis workspace by 20cm or so. I have a need to engrave the full size of the bed. I have designed a changeable mount to swap out the hotend and laser that also allows full use of the workspace. I'll share it in the future.

    Step 5: Build the Shield

    Laser light is very damaging to the eyes. Even a slight reflection can do serious vision damage at these powers. Always wear laser safety glasses. J Tech Photonics sells plexiglass laser shielding. I choose not to fully enclose my printer, so I built a portable laser shield to put in place when the laser is in use.

    If you print on a mirror, remember to turn it over before using the laser.

    To build the shield, order (2) 24x12 and (2) 12x12 plexiglass pieces. Print two corner connections, three stand offs, and four top corner connections from the files below. Use the the two corner connections to connect the two 12x12 pieces to one of the 12x24 pieces. Use the four top corners to mount the second 24x12 piece to the top of the other 3 pieces. Set the shield on the three standoffs. A little dab of hot glue will hold them all together.

    Having the shield in place while you are using the laser will protect your sight and that of anyone that walks into the room.

    Step 6: Learn to Engrave

    This will take some practice. My advise is to start with the 30 day trial of Lighburn and then purchase it if you plan to continue. It's only $40 and well worth it. Don't waste your time trying to make the free tools or plugins work. Lightburn is the easiest starting point and it just works without a lot of hassle.

    Lightburn has a nice "Focus Test" feature under "Tools" that can help you focus the laser. I have my BLtouch mounted with the laser engraver and it makes it easy keep the laser a consistent distance above the bed to keep the focus.

    Start simple learn the speed and power you need for different materials with practice.

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      12 Comments

      0
      Bocamarc
      Bocamarc

      Question 18 days ago on Step 6

      Hi Jerry,

      I have the same Neje Laser and I am trying to get it to work with my 3D Printer. The laser comes with a driver board and I don't see it in your setup. Did you eliminate it ? Are there any issues not using it ? Any concerns ?
      When I try to hookup my laser with the driver board, the laser stays on and does not get controlled by PWM. However, I can control an LED bulb at the output of my 3D Printer board before the signal goes to the laser driver board. Any suggestions on how to get it working ? I was relutant to eliminate the driver board. Not sure of the implications.

      0
      Jerryolsen
      Jerryolsen

      Answer 18 days ago

      My first laser didn't come with a board and I just connected it as in the Instructable. A second one came with a board and I didn't bother installing it and it worked just fine. I think the board is necessary if you don't have another way to drive the PWM.

      0
      Bocamarc
      Bocamarc

      Reply 17 days ago

      I finally got my laser working with the driver board. I'm not sure why it wasn't working before. I believe my Marlin firmware was the configured the same and the wiring was identical. Perhaps I missed something or there was a wire shorted. It appears to work reliably. I've booted up several times and have adjusted the laser PWM/intensity successfully.

      I read online from someone that if you connect the laser without the driver board it can work, however, you can damage the laser or reduce its life. If I find the comment, I'll post the link.

      0
      rowaller
      rowaller

      5 weeks ago

      Hey Jerry,
      I've sent a private message to you but I guess an answer for everyone will be better so I post it here :)

      This is a project I'm working on too, but on an Ender 3 Pro, so 24v psu.
      No problem to get 12v out of the psu, but I'm a bit more sceptical about the pwm wiring.
      My cooling fan is 24v so I guess my pwm port is 24v regulated output too. Any advice to get the right wiring from my motherboard to my 3500mW ttl laser?

      Again thank you so much.
      Waiting for your answer,

      Best regards,

      Romain.

      1
      Jerryolsen
      Jerryolsen

      Reply 5 weeks ago

      I answered your PM, but this would be a good answer for the rest of the community. The MOSFET that provides the 24V to the fan has a 5V input. Solder a 100 ohm resistor to the 5V input of the MOSFET (picture in the instructable) and connect that to the PWM of the laser.

      0
      rowaller
      rowaller

      Reply 5 weeks ago

      Thank you so much for your answer.
      The laser unit is this one:
      https://a.aliexpress.com/_BUGX3T

      It says in the description:
      PWM/TTL Input:DC3.3V-12V

      Do you think it's ok with your 5v wiring? Is it what you call 5v standard ttl ?

      0
      Jerryolsen
      Jerryolsen

      Reply 4 weeks ago

      Yes, it will work. 5V=Standard TTL.

      0
      jessyratfink
      jessyratfink

      6 weeks ago

      That looks great!

      0
      Jerryolsen
      Jerryolsen

      Reply 5 weeks ago

      Thanks!

      0
      KarlK49
      KarlK49

      Question 5 weeks ago on Introduction

      Which laser module are you using? The 600MW or 2.5W. Does the Lightburn software communicate to the printer through usb? Would you consider doing a tutorial on using the software?
      Thanks! Karl

      0
      Jerryolsen
      Jerryolsen

      Answer 5 weeks ago

      I have both a 750MW and 2.5W both work well. I have Octoprint connected to the printer and move the Lightburn output to Octoprint and then I can control and print from there.
      There are plenty of tutorials on Youtube for Lightburn, but I can certainly answer questions and may update the Lightburn step in the instructable.

      0
      pmillho
      pmillho

      Answer 5 weeks ago

      I'm assuming the 2.5W. If you look at the first image under Step 4, you can just make out "7w" on the side of the laser module. In the product description it says the 2.5 laser is for a "7000mW Master DIY Laser Engraver Machine Replacement". 7000mW would be 7W.