Yesterday I was doing projects, jogging and today my laser movement with or without continuous jogging is erratic at best.
I’m using a J-Tech 14W Pro laser that is fitted to my X-carve 750mm x 750mm cnc, Lightburn version 1.7.04. I enabled the continuous jogging this morning and have had nothing but problems with jogging in general ever since. I verified that all steppers are working properly through Easel as far as the gantry moving in the proper direction n,s,e,w and up and down. It homes when i send it there, starts and stops as required. It appears to be a Lightburn issue. The gantry will move n,s,e and w once then it will not go s twice. a few minutes later i can repeat this. I can also get it to go to its origin.
Thank you, Mikey. I will check that when i get home and let you know what i find and if it helps. What exactly does (DTR) stand for? The $J continuous jogging is enabled.
In communications, “DTR” stands for “Data Terminal Ready,” which is a control signal used in serial communication to indicate that a device, like a computer, is ready to send or receive data, essentially signifying that it is prepared to communicate with another device.
It is basically an RS-232 thing. It basically the controller tells the source when it is ready to receive more data. It is a 2-way talk between the 2 devices, so it is slower than without it turned on. But faster than we can read.
I turned on the DTR and it made no noticeable difference. The only thing that works is turning off lightburn then turn on Easel. I home easel to Z-0 then turn off easel and turn on lightburn and set origin with it still at Z-0. I can then use continuous jogging on lightburn with no issues until of course i turn it off and then on again. It only takes a few minutes though something is amiss.
I don’t usually recommend this, but have you tried reinstalling Lightburn? I do not rember reading any other postings describing your symptoms. A quick search did produce a lot of stutters. Have you tried running slower?
No, I have not considered it only because I really am not advanced enough to set all of it up again on my own. I’ve had and used cnc machines for about two years and never had this issue with continuous jog until lightburn. Initially I had assistance from a tech at J-tech lasers assist me in setting up lightburn and it was all good. I too read and read forums all over the web with nothing describing the issue i was having. I did read about and had a stuttering issue with a stepper motor and It ended up that the Z stepper motor board was fried and I had to replace the entire board. After replacing the board everything worked fine until I began to use the continuous jogging feature in lightburn. As I stated before i did find a work around though I don’t believe I should need to do that.
This leads me down a different path. Is it possible you have the accel rate set too high? I think this would max out the initial current to the motor. And that could fry a board if the driver current is set too high.
Turns out stepper motors don’t work like Old School DC motors. The stepper driver controls the current to the motor, with reference to a setpoint from either a twiddlepot (in low-end IC controllers), a firmware config (for more recent IC controllers), or DIP switches (in separate drivers, as in CO₂ lasers). As a result, the motor current is essentially constant, regardless of the speed or acceleration.
Another surprising result: because the current is constant and the supply voltage is constant, the motors operate with constant power and don’t get any hotter whether they’re standing still or running at full throttle.
So the numbers are ok is what I’m getting? I know the stepper motors were never an issue on the X-Carve cnc before introducing the J-tech laser and adding lightburn to the equation. I can move the gantry at the pace i want.
So i still have the continuous jogging issue. I’ll contact lightburn and j-tech tomorrow to see what i can find out.
I do have it set in mm / min as that is what i use and is what lightburn has for a diode set up in units and grids as default. Both of my cnc machines are set to mm as this provides a much more precise measurement and this has never been an issue until lightburn. To be fair i really don’t have an issue with the speed unless it was the cause of my board frying. My issue and the reason for this post was that the continuous jogging isn’t working properly or continuously unless i do the work around noted earlier in the chain.
It will be helpful to get a look at the GRBL config, either through the $$ list copypasted from the Console window or screenshots (rather than photos) of the LightBurn Machine Settings. Also, a screenshot of the Move window will show the speed settings used in several commands.
Then we can look your shoulder and help debug the problem starting with the actual config.
[quote=“wingfanz, post:5, topic:162522”]
I turned on the DTR and it made no noticeable difference. The only thing that works is turning off lightburn then turn on Easel. I home easel to Z-0 then turn off easel and turn on lightburn and set origin with it still at Z-0. I can then use continuous jogging on lightburn with no issues until of course i turn it off and then on again. It only takes a few minutes though something is amiss.
Having the machine burp out errors suggests something is wrong at the firmware level, well below where LightBurn gets involved.
Because $22=0, the controller does not home when it’s turned on, which means wherever the laser head happens to be will be the (0,0) machine zero origin position.
Unless you follow the Manual Homing procedureevery time you turn it on, subsequent motion commands are guaranteed to result in heartache & confusion, because the controller does not know where the laser head is on the platform.
Because jogging uses motion commands, it can’t work until the machine is properly homed.
That generally occurs due to a USB communication error wrecking a command in flight. If you have not already followed the USB debugging process, now’s a good time to get started.
I changed my ferrite USB cable to one I know for a fact is good, not that the one currently attached wasn’t, I turned on auto home on start up in lightburn, closed the program, shut down my laptop and restarted it. I went directly to lightburn. Continuous jog was already enabled and the machine homed at Z-0. I jogged steadily without any stops to the NW and NE with no problem then toward SE and the gantry stopped at roughly the halfway point, then W and the gantry stopped short of the center of the waste board. I rehomed the gantry and went to the NW and tried to to move from NW to home and again the gantry stopped at the midpoint. I have limit / homing switches for all directions and they all work properly.
LightBurn’s auto-homing depends on having the machine correctly home itself.
If GRBL has homing disabled and you do not do the manual homing dance on every startup, then what you describe is exactly what should happen.
If the machine has homing switches, enable GRBL’s homing and verify that it works correctly when you turn the machine on.
If the machine does not have homing switches (or you don’t want to use them), then you must do the manual homing dance every time you turn it on. That must happen before you connect LightBurn to the controller.
Knowing your name and phone number, I know your address. Combine that with your hobbies and I can estimate when you’re not home.
Knowing your email address, I can sign you up for even more spam than you’re getting now. Combine it with your hobbies and I can spear-phish you with exceedingly convincing AI voice spam.
Although all your data is public information in other places, the policy around here is to minimize the cross-section for malefactors.
