Dear friends, I need your help with my project. I am building a 80w cnc laser. I havent started the build yet, I am collecting the parts. So far I have got the openbuilds rails for the FRAME, an 80w TUBE, and an 100w PSU. Now I am looking for the controller. I have an old XPRO v2 that I havent used ever from an old cnc build, and a classic arduino board. I am thinking if I could use the xpro, or the arduino with a cnc shield v3/v4, or if I should look for another controller option. I have read some posts but it seems confusing, I am not sure if it will be safe to use grbl with co2 laser. Do you believe I could use the xpro v2 for that build? What should I look for? Where could I find the appropriate firmware/software, and what should I be aware for, so I will not hurt myself or any equipment? I appreciate any kind help! Thank you in advance my good friends!
You'd have to upgrade Grbl on the xPro to grbl 1.1 to get Grbl v1.1 Laser Mode · gnea/grbl Wiki so you can use docs:software:lightburn [OpenBuilds Documentation] at optimal efficiency. However, some xPros came without bootloaders, so you will have to try. Download OpenBuilds CONTROL from OpenBuilds Software - FREE Software for CNC Control: OpenBuilds CONTROL and OpenBuilds CAM and go to Wizards and Tools > Firmware flashing tool to give it a go. Try the xPro and Uno options. If neither works, yours has no bootloader and would be hard to flash Then, get yourself a BlackBox instead - see https://docs.openbuilds.com/blackbox
Most importantly: the most expensive, rated for CO2 laser wavelengths, correct OD rating - protection goggles you can get. Replacement corneas are expensive! Blindless is no fun. And an Interlock on the enclosure door (tied into WP line on laser PSU to cut beam if lid is opened) laser safe window in the door, and, well should have had this earlier in the list, but Nb to have the entire laser enclosed in a fireproof enclosure (not a wooden box) And if you are planning a motion platform too: do not get tempted into dual-y motors with a flying optics setup. Must be a fixed driveshaft system to prevent carriage skewing at all.
Thank you for your answer! Sure goggles are on my list, wouldnt try anything without goggles. I will check if i can upgrade to grbl 1.1 and will came back. I just checked the blackbox option, looks promising, but havent found yet a co2 built with this controller. The machine will work with two motors, one for X axis, and one for Y axis. No dual Y axis, just one motor that will move both gantry plates with a rod. Like the way k40 is built. My biggest concern is connecting right the PSU to the board, and setting the firmware right for that job. Thank you again!
There are quite a few: Search Results for Query: blackbox co2 | OpenBuilds Yes! Safest way! Easy Peasy : See Advice on CO2 Laser Build (also a couple other spots on the forum) or post pics of your connectors on your laser PSU with its labels and we'll rewrite the reply here with specifics.
I believe I have upgraded the xpro v2 from grbl 0.9, to grbl 1.1h. I have downoaded the hex file from here Releases · gnea/grbl, and with the way you suggested, through openbuilds control, I upgraded. Although in the openbuilds control it says GRBL 1.1g , is this normal? Thank you!
Succesful upgrade yes. If it says 1.1g, you picked one of the other options in the list. If you wanted to flash the hex, you can use the Custom entry The Hex is not really perfect for a laser build though - if you don't have a Z axis for example, rather flash the 2-axes option from the list
Yes I saw what choose wrong! Havent seen your post, and already installed this v1.1h, custom, XY Homing 20190830 firmware from here Flashing Grbl Firmware – LaserGRBL I am very newbie to this, and I am not sure I do the right choises, but is seems that I have installed this OK. Do you believe its better to choose the 2axes option from the menu, rather than using this custom XY firmware? Thank you again!
I don't know LaserGrbl (Official Grbl has a complete and excellent Laser Mode baked in already: Grbl v1.1 Laser Mode · gnea/grbl Wiki so no need for a fork) which is what we run - the 2 axes build removes Z-homing (i.e we did Frequently Asked Questions · gnea/grbl Wiki for you so you don't need to recompile yourself. Then you just need Lightburn and set it up as shown here docs:software:lightburn [OpenBuilds Documentation]
I will look for that! Have found a thread "K40 ACRO Conversion" that the builder uses xpro, and I take a look at what he have done! Thank you!
Hi, this is a very nice build! Congrats! I am in the process of doing something similar to this, with an 80w tube and 100w PSU. Could you help me figuring out how to connect the xpro with the PSU (attached image - psu pins) ? Is it possible to have a test fire switch, on-off switch, and potentiometer? I understand that I will need to build a logic converter for the xpro. Is this enough to prevent the tube from firing when the controller boots? I have loaded the firmware 1.1h-custom XY homing, but I cannot find the config file. Could anybody help me to figure out what it is needed to do to have the controller ready to run the machine? Thank you in advance!
Only with the K40 PSUs that only have TL input. Your pics shows you have a better PSU with TH and TL Potentiometer: Yes: Potentiometer left terminal to GND, Wiper to IN and right terminal to 5V ON/off switch: YES: In series with door interlocks and water protection sensors in the WP/GND LOOP Test switch: Yes Rather use the stock Gnea/Grbl as discussed in your other thread - LaserGrbl is less widely used a remnant from the Grbl 0.8/0.9 days - forked, author wrote an app for it, closed ecosystem. Standard Grbl is more widely supported (LaserWeb, Fusion Posts, Lightburn and many more). With laserGrbl you kind of have to use their application too - limited choice Configuration: You need to configure it: See Grbl v1.1 Configuration · gnea/grbl Wiki - you can start off with our Acro profiles as an example (OpenBuildsCONTROL > Grbl Settings tab > Select Acro from the list. WP->GND = protection loop. If door is closed, water is flowing, and keyswitch is in the armed position - they are all closed in series in connecting WP to GND. If any goes open, protection loop no longer has WP connected to GND and the beam is cut off. Do not short-circuit as shown in that diagram. Its a safety input. USE IT TO KEEP YOU SAFE, do not jumper it to override safety! TH/GND: Connect to GND and PWM on Grbl controller's outputs 5V/GND/IN: Potentiometer input - also scales PWM input for realtime power override TL/GND: usually not connected, though here you can wire that Test button for a front panel test fire.
Dear Peter, thanks for recommendation, now I installed the grbl_v1.1h.20190825.hex from here Releases · gnea/grbl. Yes the PSU is different from K40. If i understand right, the wiring should be like the attached image? Except I am stuck with where the D11 and 5v from xpro should go. Thank you (Sorry for the bad sketch, I will try to make it better!)
Into H Not connected, PSU has its own 5V supply - that 5v pin is an output I would put ON/OFF in series in the protection loop (so its a proper arm/disarm switch for ANY signal, not just the test button like you have it now)
Thanks! Does this wiring look better/right? I feel a little confused about what you said for the test button.
You got that right. The PSU has options for a logic high and logic low input (more a leftover from years past - different controllers). Because we have a logic-high PWM output of Grbl we use the H(High) input for signals from Grbl. But the unused LOW input is not used by Grbl, so you can wire your button to that - it expects a LOW so we have the switch close to GND to pull the input LOW. perfect!
I cannot thank you enough! I feel relieved from this wiring stress! I will keep posting in my thread as I make any progress, hoping my project will work! Thank you again!
I keep tinkering and managed to compile and upload the firmware, instead of using the hex file. I also downloaded the trial lightburn and looking forward to learn using it. In the config file, I commented the default Homing Cycle, and uncommented these lines #define HOMING_CYCLE_0 (1<<X_AXIS) // COREXY COMPATIBLE: First home X #define HOMING_CYCLE_1 (1<<Y_AXIS) // COREXY COMPATIBLE: Then home Y My question now is, if I should also change these lines, as I have read suggested for k40 lasers These are the following: Invert spindle enable pin by enabling: #define INVERT_SPINDLE_ENABLE_PIN // Default disabled. Uncomment to enable. Enable variable spindle speed if not done by default. This gives you hardware PWM on Pin D11. #define VARIABLE_SPINDLE // Default enabled. Comment to disable. Remap spindle enable pin to pin D13 by enabling (WARNING! WILL BE PULLED LOW BY BOOT LOADER DURING POWER UP! DEACTIVATE YOUR LASER DURING STARTUP OF BOARD IN ORDER TO PREVENT FULL POWER BURNS AT STARTUP.): #define USE_SPINDLE_DIR_AS_ENABLE_PIN // Default disabled. Uncomment to enable. In file spindle_control.c I changed the PWM prescaler for the laser to make it more precise and easier to control by changing line 94 from TCCRB_REGISTER = (TCCRB_REGISTER & 0b11111000) | 0x02; // set to 1/8 Prescaler to TCCRB_REGISTER = (TCCRB_REGISTER & 0b11111000) | 0x01; // set to No Prescaling Also I have read this comment "Be very careful. I've seen the laser fire while the arduino is booting. Make sure to connect a 10K resistor from Arduino ground to LPS TH. The arduino boots with all pins as inputs and pin 11 can float up enough to activate the laser". Is this 10k resistor something I will have to do to be safe? Thank you in advance for your kind help!
No, because : You don't have a K40 PSU stop following K40 guides Very unlikely to be needed. But you will know when you are up and running by doing a simple grayscale raster job. Your good PSU (not the K40 piece of garbage) will probably be fine with standard PWM. A good PSU wouldnt have floating inputs. I doubt you'd need to
Thank you Peter! So, the firmware for now its ok just with the XY configuration. I have ordered the stepper motors, a 24v/350w psu for the xpro, limit switches and some other things, and waiting to test them!
Sorry to ask again, here is the answer I get from the spark concept about connecting the CO2 laser: "For the laser, you will want to connect to the output called " Variable Spindle PWM" - this will go into your "Control signal" on the laser driver. You will also need to connect xPRO Ground, to the Signal Ground. You will need to supply an enable signal to your laser module, you can do this by jumping it to a 5V signal so it is always on (might not be safe depending on the laser), or using the Spindle Direction or Coolant Enable signals from the xPRO. Spindle direction will rise and fall based on M3 vs M4 command, Coolant will rise on M7, M8 commands, fall on M9 " The first two I believe is done in my scheme. What about the last, for supplying an enable signal? Thank you in advance!
Ignore that and go with the above ^ at post #12: Controller (GRBL) for custom 80w CO2 laser I've built several CO2 lasers over the years (have two of them posted under my old username on here, before I started working for OpenBuilds) openBuilds FreeBURN-1 V-slot CO2 Laser (60-100w) openBuilds FreeBURN-2-Mini V-slot CO2 Laser (40-50w) If you do that you loose the front panel potentiometer - and I much prefer an realtime override potentiometer (;
I understand! Thank you! I will leave the firmware as is for now, maybe I will have to make changes when I will connect the steppers and the limit switches, will see!
