[muhackl666]

Dear CNC Zone community,
I'm a happy user of a quite cheap Chinese laser (DIY kit - this one:NEJE 500mW Desktop Violet Laser Engraving Machine Printer DIY Kit - Silver + Transparent - Free Shipping - DealExtreme).
It - theoretically - works fine for my purposes (see below). The only thing that won't work is my knowledge and understanding of the software I need, to get the relults I'm looking for.
Mainly I have to "print" QR codes on wood. So I tried getting some fitting .nc files with the help of Inkscape (https://inkscape.org/en/) and the gcode tools extensions. I'd like to transform the QR code graphics into paths the laser can work with.
There is absolutely no problem of getting the outlines. But I am not able to get the gcode filling the areas of the small squares of the QR code with paths.
I was not able to find a tutoral for the correct settings here in this forum or at youtube or somewhere else in the web. So I hope finding help from you.

I don't need to stick to Inkscape. If you know another tool that will transform graphics in usable .nc files for my laser, I would be totally happy.
I also don't stick to a specific OS. The software can be made for Windows, Mac oder Linux. I don't care as long as it works.

Many thanks in advance for your help and best regards
Mu

[jeffery926]

Take a look at our PicEngrave Pro 5 image to gcode program.

www.PicEngrave.com - Pic Programs

[muhackl666]

Thank you for the hint.
But the demo mode is not allowing me to create a gcode file and without knowing the result will be the one I'm looking for, I wont buy your software. Sorry.
Looking forward to some other hints.

[jeffery926]

The PicEngrave Pro 5 Demo does let you generate a gcode for testing using your own image. The image would need to be Dithered first for the laser engraving machine you linked.

You would need to use the Mach3 TTL engraving profile and set the Mach3 TTL Port like this so the laser will come ON in black areas and OFF in white.

Try it.

[muhackl666]

Ok thanks again for the hint. THe program isn't self-explanatory and it took my a while to find it.
The outputz though isn't usable with the GRBL controller. The visualizer doesn't show me a thing after opening the gcode-file. Your program exports a .txt file wich I renamed to .nc afterwards.
What did I do wrong that it won't work?
The gcode file itself doesn't look very promising when opening it in an editor. I attached it here. It's supposed to be a QR code.

[jeffery926]

You can change the file extension it's save to by replacing the txt with nc.

You did not set a Pixel Resolution (step over & step ahead) and that is why it just generated X0 & Y0 axis move commands. You also did not set a feedrate.

There are Tutorial & Help PDF files you can open for instructions.

Try settings like this.

[muhackl666]

Well that almost is it. I like your program more and more.
Sadly I can't evaluate the result because it is cluttered with watermarks.
Do you think it would be possible for you to generate a .nc file out of a random QR code for me so I can test it with my laser (without watermarks)?
30 x 30 mm would be perfect.

[jeffery926]

Here it is. I could not upload a file with a nc extension, so I changed it to txt. You will have to change it back. If the feedrate is too fast or too slow, just edit the file.

[muhackl666]

Thaks a lot. That totally made my day.
This is almost the result I was looking for.
There is jaust one thing left that bothers me. It takes my laser 24 minutes to "print" this 3x3 cm QR code. Thats way too long and I hope I know the reason. It might me the mathod you chose. Mach3 TTL works with on/off for every "pixel". So its quite a stuttering to print a simple line.
If I print a outline path, the laser does not go on an off all the time but goes on at the start of the line and of when there is a break / at the end of the line. What method and paramaters do I have to chose to achieve that for my QR code and the lined gcode your software generates?
When this would be possible, the code would be printed in several minutes. And I would be very likely to buy your software ;-)

[jeffery926]

You may need to do some changes to your grbl settings. What grbl does your laser engraver use so I can make some suggestions?

In the Laser Options you need to select the Laser Edge for an outline path, but also set the Width in Pixels which is based on the Pixel Resolution your using. With a .254mm Pixel Resolution and a 1 Pixel Width, it will engrave 1 line around the outside border, but if a 2 is used for the Pixel Width, the second pass will step in .254mm around the border, 3, ect, ect. You can also set a different feedrate for the border too.

I just looked at the gcode it generates for the border and it turns on with a M03, then travels with the set feedrate around all four sides, then turns off with a M05, then back on with a M03 to start engraving the qrcode.

[muhackl666]

First of all thanks a lot for all the patience you have with me.
I'm really happy someone is helping me with this problem.

Now lets try to get the last steps straight.
Where can I get the information about what grbl my laser uses? To control it, I use the grbl controller: Grbl Controller 3.0 | zapmaker
Actually there are no laser options as you decribe it
If I load the gcode file you generated into grbl controller, it looks like this (below). Lines. But it goes on and off (see video: https://www.dropbox.com/s/2ppfvbjxyh...%2055.mov?dl=0 ) for every pixel and not at the end of the line.

Attachment 298414

[jeffery926]

You can't rely on that viewer. It's not accurate.

Download this one. https://www.cncedit.com/Basicviewer/

Below is how it looks in this viewer. Try it.

When you connect to the com port with your streamer, it should give a message what grbl is loaded. grbl 8c or grbl 9g?

You may want to consider a better gcode streamer also, www.picengrave.com - PicSender

The Laser Option I am referring is in the Mach3 TTL engraving profile in PicEngrave Pro 5.

[muhackl666]

The Basicviewer is great. There you can see perfecty that and why the lines are dotted. How can I achieve that the lines are drawn in one piece without dotting it. like it does when I print the outlines (see pic).
The PicSender says its grbl 0.9a. And error Bad number format.
The streaming of the gcode you generated needs as much time as it needs with the grbl controller. BUT: It rather engraves than it prints. It burns down the Balsa wood I use for approximately 0.5mm whereas the grbl controller slightly prints the lines and you can even see the spaces between them.
I can feel it - we are almost there. If we can find the trick to gain more speed I will be happy.
Attachment 298582

[jeffery926]

The gaps between the burn lines is because of the stepover (Pixel Resolution) I used. I'm guessing at the settings because I do not know how small a focal point you are getting with your laser. PicEngrave Pro 5 is completely adjustable and that is why the demo will generate gcode for the user to test with. It's difficult for this trial and error process when I'm generating the gcode here, and your testing it there.

This time I will try the Variable Feedrate engraving profile with a smaller stepover. It will turn on your laser at the beginning of the file, then run fast in white areas hoping it will not burn, then slow in the black areas to burn. Unzip the gcode file, then change the extension to nc again.

You will need to make some changes to your grbl settings also. First in PicSender, select the Display Settings button. In the Messages window, copy/paste your original settings somewhere. It will show the cursor with a red circle with a line through it, but you can still highlight the settings to copy them. Then, type or copy/paste these one at a time in the Do Cmd. window and select the Do Cmd. button to make the changes in grbl.

$0=30

$1=255

$10=18

$11=0.005

$110=4000

$111=4000

$120=1200

$121=1200

[muhackl666]

Thanks! This seems to get us one step closer. The laser now draws the lines without stopping.
Interestingly, when I put the file in PicSender, the square only gets about 2 x 2 cm. If I put it in grbl controller, it has a side length of about 4 cm.
This time - if I see it right and when I check it in Basic CNC Viewer - it is just a rectangle and no QR code, right?

When putting the commands in Do Cmd, it tells me "error. invalid statement" at the last 4 commands:
$110=4000

$111=4000

$120=1200

$121=1200

[jeffery926]

I just laser engraved that qrcode on Birch Ply using our EmBlaser https://darklylabs.com/ and the only difference was, I added a S100 at the begining of the file to set the laser power level. It has a 2.8W Nichia 445nm LD and it's grbl can run a range of S0-S255. It engraved exactly 30cm X 30cm using our PicSender streamer, so there must be a problem with your machine.

Since that file was generated with a variable feedrate with a F (feedrate) command at the end of each line of gcode, it will just show up as a rectangular block of lines in a viewer. Don't expect to see anything different.

Evidently your grbl 9a does not have the same settings as grbl 9g does. Copy and Paste your grbl settings here and I will recommend the changes you need to make.

[muhackl666]

Those are my settings:
$0=30.000 (x, step/mm)
$1=80.000 (y, step/mm)
$2=80.000 (z, step/mm)
$3=10 (step pulse, usec)
$4=500.000 (default feed, mm/min)
$5=500.000 (default seek, mm/min)
$6=192 (step port invert mask, int:11000000)
$7=25 (step idle delay, msec)
$8=100.000 (acceleration, mm/sec^2)
$9=0.050 (junction deviation, mm)
$10=18.000 (arc, mm/segment)
$11=0 (n-arc correction, int)
$12=3 (n-decimals, int)
$13=0 (report inches, bool)
$14=1 (auto start, bool)
$15=0 (invert step enable, bool)
$16=0 (hard limits, bool)
$17=0 (homing cycle, bool)
$18=0 (homing dir invert mask, int:00000000)
$19=25.000 (homing feed, mm/min)
$20=250.000 (homing seek, mm/min)
$21=100 (homing debounce, msec)
$22=1.000 (homing pull-off, mm)
ok
Done
According to Pic sender.

Along with the laser there were some nc example files. One of them was a QR code that works quite well and really really fast. The laser needs approximately 2 minutes for it. I attached it. Perhaps you can read something from it.
https://www.dropbox.com/s/ubcife81xy...codenc.nc?dl=0

[jeffery926]

That looks like grbl 8 settings, but could be early 9a also.

$0=80.000 <--------------I assume this one was changed by my previous suggestion, so change it back to the 80 step/mm value. That's what caused it not to engrave the correct size.

Here are the rest that should be changed.

$4=4000
$5=4000
$7=255
$8=1200 <-----------the accels can be set as high as $8=12000, but test it at the $8=1200 setting first.
$9=.005
$10=.006
$11=25
$12=4

You can just Copy/Paste them one at a time into the Do Cmd. window and select the Do Cmd to change them.

After changing these settings, try running both of the gcodes I posted again and let me know which works best.

[muhackl666]

WOW!
That totally nailed it! Suddenly I've got a speedy laser here.
It's th $8 that speeds it up, right? The qr code is done in about 10 minutes I guess. Before the change, it needed 24 minutes.

Only the first qr code works. The second one is still just a square.
And at the moment, the "picture" is quite bright and you can see every single line.
And the motor for the x axis always makes a hissing noise and gets warm, event when it is not moving. I think there is something wrong now the settings were changed. Do you have an idea what it could be?

[jeffery926]

It's the $7=255 setting. Try changing to $7=155. If it still makes the hissing noise and stepper gets warm, try lowering it even more. Default was $7=25.

Both the $8= and $9 settings increase performance.

Try this one. I slowed the feedrate and reduced the Pixel Resolution (step over).