Where is the laser engraving category?

Since G-Code is just text, can’t any text editor just do a global Find/Replace for the Z ups/down to laser on/offs? Does any of that affect the original zeroing of the Z to get the laser properly focused on the surface of the work or is that manual jog?

Yes, any search and replace works fine.

I tend to manually jog then focus the laser (on low power) then zero the machine in CP then send the job. If you are marking or thin material cutting, everything is done in a single pass so no Z movements are required.

Cool, that’s what I thought. @IanWatkins, you’re inspiring me to go ahead and get that 2.8W upgrade :sunglasses: Have you tried running the program again with a slightly lower Z to see how it traces the first pass and to cut a bit more depth?

Yes, I do exactly that when cutting 3mm birch ply. I do multiple passes and actually step down the Z 0.2mm per pass. In that case I just modify the Z movements to safety height to laser on/offs.

3mm birch cuts at 180mm/min 0.2mm step down (15 passes) at 2W. So not quick but sharp corners unlike the spindle :smile:

I would expect balsa to be quicker, will see if I can find a sheet.

Got some 1/8th and 1/4 balsa on the way to try it, will report back after the weekend @AngusMcleod

If you were going to do one offs that the spindle cannot do then I would suggest the JTech laser is more than suitable. But doing lots of the same cut would be better off on a 40W laser due to the speed. Guess it is the balance between your time/machine time/equipment cost over its lifetime and how many parts you want and of course only you can decide that.

Me? I’m quite happy having the laser cut out a battery tray for an RC plane or say a rocket engine mount in 3mm ply (see this) even if it takes a few hours because I’m usually only ever making one at a time. Even then, I only reach for the laser to cut it if the spindle cannot because of the inside corner issue/or other fine details are needed.

Which reminds me, must measure and draw up the battery/equipment trays for my new RC plane before I build it. Having the ability to produce spares was actually the main reason I bought the X-Carve in the first place :smile:

Cheers

Ian

J-Tech now offers a 3.8W laser kit which would cut somewhat faster then there 2.8W unit.

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I agree, there are times when sharp corners are needed as well, but you will be surprised at what those 1/32" end mills will plow through given the right feed/speed combo. I was definitely surprised once when I forgot to set a better safe height and it cut right through my oak clamp. :wink:

Thank you everyone for your replies. This is looking more promising the more i read about it.

@IanWatkins
Would you be willing to share the automated script/macro?

@KenPhuong

Don’t have a file as such I can share so I’ll walk you through it.

Simple project, mark a single, 5mm x 5mm square using a single pass. Design in Easel using a 0.1mm DOC and make the material 0.1mm, that’ll give you a single pass. Set your automatic spindle control to request 18,000rpm (which gives full duty cycle on the PWM output). Then export the gcode.

This gives me this:

G21
G90
G1 Z3.810 F228.6
M3 S18000
G1 Z3.810 F228.6
G0 X10.000 Y10.000
G1 Z-0.100 F228.6
G1 X10.000 Y10.000 F200.0
G1 X5.000 Y10.000 F200.0
G1 X5.000 Y5.000 F200.0
G1 X10.000 Y5.000 F200.0
G1 X10.000 Y10.000 F200.0
G1 Z3.810 F228.6
M5
G0 X0.000 Y0.000

Looks good, will go set machine to mm units, go to safety height (3.81mm), turn on the spindle, move to top right of the square, lower to 0.1mm below your set zero point and then start carving. At the end of the cut, it’ll go back to safety height, turn off the spindle then return to zero in the X,Y.


First of all you want to remove all you spindle switch on commands. Simple search and delete all of these entries:

M3 S180000

This should make your gcode look like this:

G21
G90
G1 Z3.810 F228.6
G1 Z3.810 F228.6
G0 X10.000 Y10.000
G1 Z-0.100 F228.6
G1 X10.000 Y10.000 F200.0
G1 X5.000 Y10.000 F200.0
G1 X5.000 Y5.000 F200.0
G1 X10.000 Y5.000 F200.0
G1 X10.000 Y10.000 F200.0
G1 Z3.810 F228.6
M5
G0 X0.000 Y0.000

Then search and replace on all Z moves to safety height and changes them to spindle off commands. So replace:

G1 Z3.810 F228.6

with:

M5

giving your gcode now looking like this:

G21
G90
M5
M5
G0 X10.000 Y10.000
G1 Z-0.100 F228.6
G1 X10.000 Y10.000 F200.0
G1 X5.000 Y10.000 F200.0
G1 X5.000 Y5.000 F200.0
G1 X10.000 Y5.000 F200.0
G1 X10.000 Y10.000 F200.0
M5
M5
G0 X0.000 Y0.000

This gives duplicate M5 commands but does no harm. If you don’t like it you can always go through and remove duplicate commands.


Final step is to search and replace on Z downwards movements to -0.1mm to switch the spindle (laser) on. Search and replace on your step down commands, in my case 0.1mm.

Search for:

G1 Z-0.100 F228.6

replace with:

M3 S18000

This gives you a final gcode looking like this:

G21
G90
M5
M5
G0 X10.000 Y10.000
M3 S18000
G1 X10.000 Y10.000 F200.0
G1 X5.000 Y10.000 F200.0
G1 X5.000 Y5.000 F200.0
G1 X10.000 Y5.000 F200.0
G1 X10.000 Y10.000 F200.0
M5
M5
G0 X0.000 Y0.000

This job, when sent will move the laser to the top right corner of the square, turn on the laser, mark the full square, turn off the laser and return to X0, Y0. (No Z movements at all, so you don’t need to set zero/focus again if you decide you want to run it again to make it darker. It sounds a lot more complicated than it actually is.

Obviously, with cutting, you’ll probably need to do multiple passes but the same principles apply.

Hope that helps

Ian

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@IanWatkins
Thank you! I’ve earmarked this for future reference once ive gotten the laser module ordered.

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A new version of PicEngrave Pro 5 is now available for download. Unlimited user named Profile settings are now able to be Saved/Opened for different engraved materials, Pre/PostCodes or CNC machines has been added.

http://www.picengrave.com/PicEngraver%20Pro%205%20+%20Laser.htm

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In my single car garage (rental home), I continue to fight with the homemade safety box I set up initially for the laser add-on. I finally laser cut out the panels to create a box. I did a bit of a chop job on the backside trying to set up the ability to raise and lower the box. I suspect if I had to do it again, I would also laser cut out the lines on the back.

Original set up:

Updated:

Youtube video:

I likely will play with this some more but I like it so far. I did see that as some one walks up to the garage, they can see under the bottom (1/4" approx. open) so I set up the rest of the orange acrylic to block that view.

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Good job making that ingenious, simple addon to block the laser’s beam. :wink:

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Thanks. I could have sworn that I had seen it elsewhere but could not find the same box through the various forums. I would have liked to give credit where credit is due but have been unable to find the source picture again. So for the individual who made the original simple box around the laser- thanks. I like it and definitely enjoy having the significantly reduced footprint around my set up.

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We needed a new 2016 Calendar for the office, so we decided to laser engrave one on 1/8" Birch Ply. We added a border with the Laser Edge option in PicEngrave Pro 5. The engraving is 10.5" X 10.5" in size and the 3,062,617 lines of gcode was streamed to grbl with PicSender.

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Nice !!!

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Thanks Hugo.

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How long he was doing it ??

Here is some of my tests. I use for now Inkscape Plugin: Raster 2 Laser Gcode generator

Width: 70 mm
Heigh: 120 mm
Speed : 800 ( on next test i give him 1200 or 1400 speed and see the time)
Power : S600
time: 26 minutes