So i have a Lowrider Ver. 2 and finally everything seems to work, after i ordered a preconfigurred SKR 1.2 board from this site…So yesterday i hooked up my Neje laser to Fan 0, it fired and died… No clue what happend. so i need a new laser and know i am back to that this Neje would never have worked since PWM is on the ground and not on Positive of Fan 0. It only works with 12 V TTL with PWM on positive, been there …And since it just died with hardly any use, i am not keen on another Neje…So which lasers TTL works for this out of the box, i really enjoy not having to go cook firmware…And since i am in europe, easy delivery and not getting taxed to double price is appreciated…
So in short a laser that works witk SKR 1.2 Fan 0 TTL with PWM on the gnd out of the box with no firmware cooking needed…or another Pin that is ready to go…
If you are not into firmware cooking then go buy a separate laser machine because the two disciplines are mutually exclusive. (Another tin hat moment!).
To start with, if you haven’t already done so, you should upgrade to the latest V1 maintained firmware for the SKR Pro. Laser support does not require any firmware changes, so all you need to do is put the binary on an SD card, put that card in the SD slot on the SKR Pro board (not the display), and turn the board on.
With the latest firmware installed, you want to install your laser on pin PC9. You can find a pinout diagram here, and PC9 is on Extension-1 and is a 5V pin. You don’t say what laser module you purchased, but you need to verify that it will accept a 5V PWM signal. Almost all laser modules sold today will accept a 5V signal.
As for commands, you will get the best results if you generate inline commands for your laser. You don’t say what tools you plan to use to author g-code for your laser. I highly recommend Lightburn. It is capable of generating inline commands. It is a paid app ($60) with a free, four-week trial.
You need to place the following line in the top of your file for inline commands:
M3 I
It can be inserted automatically by most g-code authoring tools.
Note that there is a bug in laser menu code. It is an issue with the laser timeout that results in the laser flashing briefly and not staying on. It has been fixed in Marlin, and will be fixed in the V1 code the next time V1 upgrades to a newer version of Marlin.
The fan pins are 12V and ground-side switching. If a laser module is designed for 5V TTL/PWM, then a 12V signal can damage the module. Many laser modules will not work with ground-side switching.
If you are using a separate power supply for your laser, you need to share a ground connection between your laser and your control board.
No firmware changes are required. The NEJE A40640 is plug and play using pin PC9 on Extension-1 for the PWM signal. The extension/connection board that ships with the NEJE A40640 has a plug for the PWM signal and ground. Your only issue will be extending the wires to work with your Lowrider.
I would. The NEJE A40640 requires a 12V, 3A or better power supply, which runs around $10 on Amazon. If you purchased your Lowrider setup from V1, then it is likely you have a 24V power supply, plus, if you had a 12V power supply, it might not be large enough to power both the Lowrider and the laser module.
The NEJE comes with this companion board to facilitate hookup. You want Input A. The power is plugged into the barrel jack, and the two-pin connector is designed to connect to the control board.
Note that the companion board is not required. It is possible to directly wire to the laser.
Thanks for all the answers
I am in luck, laser still working. Its a Neje 40630, it says TTL 3,3-12V, 20KHz, does it not then need a 12V PWM Pin?
I will use lighburn or estlcam, depends on what use i find for it…First i need it to cut some 0,7mm wood, idea was that is should also engrave graphics on this, so will probably use both lightburn and Estlcam…
If it cant be avoided, firmware cookery it is I usually get away with it…
it says TTL 3,3-12V, 20KHz, does it not then need a 12V PWM Pin?
It will accept voltage PWM pin in the range of 3.0V to 12V. The only 12V PWM pins on most control boards are ground-side switching, which does not work for most lasers.
So i just hooked the Neje up to PC9, M3 Sxxx works perfect, G1 X1 Sxxx did not fire the laser…Not sure what firmware i have, Marlin 515DL 2.1.1/V27
You need to have the following at the top of your g-code file for inline commands to work:
M3 I
If you did not add this command, then the laser will not fire. It will fire with M3/M5 without this command as long as the laser is moving. If the laser is not moving, the safety timeout will kick in and turn the laser off. Most apps that generate CNC g-code have a place to enter this g-code command so that it is automatically added to the top of all g-code files.
I have a NEJE A40640 and a NEJE E40. (as well as a Genmitsu 5W diode) and all of them work fine on 3.3/5V TTL. So all of these will work fine on the V1 firmware as documented.
The boards I have are Duet 2 Wifi boards, which do not have an avaiable 5V PWM/TTL output. I found an add-on board that will work with the 12V negative switched outputs used for fans or heaters. I ordered 10 (I think) from JLPCB, which cost about what I could find just one for. So… there is a way to make it work with the fan output. The board takes 5V, 3.3V and the heater/fan switched ground and outputs a 5V PWM modulated output.
good luck finding that info… Duet is a commercial closed source brand… plenty of info on how much it costs to buy their boards, but circuit diagrams? … not so much.
Nah…that isn’t open source. You will find all the firmware and the odd picture of the system boards, and perhaps a few reverse engineered add-on boards that someone has cloned but Duet is a commercial company that has so far retained its hardware IP.
I own a few genuine Duet 2 boards and a couple of Ali Express knock offs. Before I bought the first one, I did actually check the availability of source. I like to know what I’m supporting with my purchase.
To be fair, I did not track down an actual repository for the Duet 3 boards, but since Ali Express has knock-offs of those too, I figure they must exist…
I have somenof those add-on boards, and am using the E0 heater as PWM output for my laser. The boards were intended to have a header that plugs into the expansion port on the Duet and use one of the aux heaters on a Duex expansion board, but I just soldered wire to the board for input instead.
So far, I am happy with the output. My A40640 laser works well, though I had some trouble with the 3D printed air assist nozzle. (Thanks @dkj4linux ) if I don’t actually pump air through the nozzle, I end up melting the plastic. The E40 is nicer that way, the air nozzle is metal.
Thank you Adam I’ll check that post.
I usually get away with it…
