Hey fellas so recently replaced this board with the CNC sheild for my laser however connecting the laser to the spindle enable dosent work to make it work I have to power this old board up connect the laser to this board then use jumper wires from the cnc shield into pin 11 of this board to get the laser to work correctly obviously it has something to do with the fu024n mosfet on here. I’d like to rebuild the circuit in smaller form. Does anyone have a schematic of these boards or point me in the direction on how I would recreate it? I’ve tried to re draw it but it’s incredibly difficult to see.
You are leaving off all kinds of details that are necessary to help you. What type of Laser are you controlling> What type of Arduino is CNC shield attached to? What Firmware are you using? Are you doing simple On/Off or trying to use PWM to control laser power?
@Kelly_Burns It’s a 12v TTL 5.5w 405nm blue laser. It’s a attached to a Uno running grbl 1.1f I’m using Pwm to control it. Apologies for the lack of details.
Can you post your config?
Also, what version CNC Shield? I seem to recall that the Pinout changed on on the Spindle portion at some point.
Your issue is likely to be pinout. If you google GRBL Laser CNC Shield, you will get a pretty good education.
BY the way, DONT do any of this without the laser being mounted.
@Kelly_Burns I certainly can however I think I may be wrong about the laser being TTL it just occurred to me on the drive home from work. The laser has one lead which is power there are no control leads I assumed because of the board mounted on the laser that was the TTL driver now I think that little circuit there is the actual driver and the board on top of the laser is just a constant current source?
You have me quite confused. So I’m not sure what’s going on. I haven’t seen that, but I’m guessing that board on top of the Laser Module is the Driver. I haven’t personally seen on of those and I’m uncomfortable advising on a device I am not at all familiar with and can have safety ramifications. Without more information about what elements you removed from original device and what it looked like before, I’m at a loss.
I have the same laser module and the board on top is a constant current driver. You can not PWM modulate the power source.
You need to connect constant power to the input, otherwise the fan will not work (with low pwm) and the diode will probably burn.
There is a TTL pin on the driver board right behind the test button. You can use that to modulate the laser diode, but it’s not very linear.
I ended up replacing the driver board with a decent pwm laser driver.
Thanks for chiming in Claudio. I stopped trying to guess with these Chinese boards and controllers if I don’t have first hand experience. Seems like a reasonably priced Diode Laser. How does it do with external pwm driver?
@Kelly_Burns It performs ok, but a year ago it was hard to find a matching driver with engough power for a good price, so I used one of these (even if they don’t deliver enough power): https://de.aliexpress.com/item/12V-TTL-1W-2W-3W-445nm-450nm-Laser-Diode-LD-Driver-Power-Supply-Stage-Light-lighing/32684581863.html
@cprezzi brilliant thank you sir!
I guess the diode in the module is a 3.5W (typ) Nichia NDB7K75 (http://deals.guanxiweb.com/Product/262022796281/Nichia-NDB7K75-450nm-3500mW-35w-9mm-high-power-blue-laser-diodeBrand-New-1-pcs)
http://deals.guanxiweb.com/Product/262022796281/Nichia-NDB7K75-450nm-3500mW-35w-9mm-high-power-blue-laser-diodeBrand-New-1-pcs
If you did not buy the module yet, i suggest to buy one with a better TTL PWM capable driver like this one: https://de.aliexpress.com/item/5-5w-high-power-450NM-focusing-blue-laser-module-laser-engraving-and-cutting-TTL-module-5500mw/32559183201.html?isOrigTitle=true
This one seems to be a decent driver (not tested): https://www.ebay.com/itm/BlackBuck-8M-8A-modulated-buck-laser-diode-driver-for-NDB7A75-NUBM44-NUMB08-etc/152552874043
@cprezzi Speaking of the TTL pin ive soldered a wire to it connected constant power to laser which fires the fan up and the laser i then connect the TTL pin to + spindle_enable which turns the laser off but i cant seem to get it to fire are there any settings that need to be adjusted in LaserWeb? Would like to test this before buying a new driver.
Did you check which pin the single output was on? CNC shield is a certain pin and it likely doesn’t match your Grbl.
@Kelly_Burns So been doing some tests Flashed a mega with GRBL-mega hooked up my laser to pin 7 (VARIABLE_SPINDLE) and i’m able to modulate power perfectly. However when i try to do the same on my Uno with the sheild the laser wont turn on i’ve checked the GRBL config.h file VARIABLE_SPINDLE is enabled but its not firing the laser so i tried plugging the laser into SPINDLE_ENABLE which fires the laser but with no pwm. So to test i attached a jumper wire to the TTL+ and went across each Digital pin none of which seem to be VARIABLE_SPINDLE. Considering i have had the laser PWM working on the mega im guessing its down to a issue in config? Thanks for all your help hate to the be ask a million questions guy.
@Reece_Ketley Since Grbl 0.9j the pins for SPINDLE_ENABLE and Z-ENDSTOP has swapped. If your CNC-Shield is the old version, then you must connect the TTL pin to one of the Z_ENDSTOP pins (D11).