What am I doing wrong? (Nothing now)
So I have the gerbil working, it will do ovals and triangles, it will also happily raster but I'm getting pretty poor results (obviously my setup but what I don't know)
So I tried to start with an image that I know the output of to calibrate it, did the Inkscape bit and set a speed of 1000, chose grayscale, 256 levels etc and outputted the gcode.
Next I loaded that up into CNCjs and ran it through. I changed the $30 value a couple of ties during the raster but a) it wont do black, b) there don't seem to be many levels of gray and lastly the light parts don't engrave at all which looks really wierd.
Any tips of what I can do to try and get it better? The numbers I have scribbled down are the $30 value.
I have the PWM cable connected also.
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Ok, bad form to reply to your own thread I know but I had one last go, It came out better than before, how white is supposed to engrave?
The petal tips on this haven't lasered at all, even the light grays so I still think I have an issue.
This was at $30=1800 and 1200 for engraving speed.
I tried to engrave this https://static.pexels.com/photos/57905/pexels-photo-57905.jpeg
Any tips.
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Hi Tim, what's your $28 value? Default should be zero '0' but you can try other frequencies (mode: 0 til 6).
It seem you are getting the best results with a high $30 number (4000).
Try to engrave with 64 and 128 shades and see what comes out for debugging purposes. Also you might need to set the picture resolution in inkscape to 380 dpi (standard 96)see attached screenshot
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Some good thoughts, thank you Paul. It is definitely working and I am getting PWM which is good, I ran a grayscale calibration jpeg and managed to get from black to about 8 greys up so was missing the top 2 (the 11th is white)
What does $28 do? I've looked at the GRBL settings list and none of them seem to mention $28. *Edit, took some finding but I found $28 description here, thanks https://awesometech1.wpengine.com/other_lasers/
I'll try later today and report back ????
Well those changes definitely made a big difference, I got a good flower, I left $30 the same and swapped to $28=4, and did the changes in Inkscape, (DPI and number of greys) trying something a bit bigger this time.
Out of interest, when I asked at the kickstarter you were using 3mm Birch ply? If so, on a dark part of the engrave how deep roughly was is burning? Mines pretty deep and ends up almost 3D, just checking that is right because when doing a halftone on the old board it isn't the same (obviously)
Hi Tim, yes it is pretty much almost 3D carving. That gave me the best results. However I have done a few light engavings as well that turned out well. It depends also on the plywood. Some give nice shades some don't.
Quote from Tim Anderson on December 29, 2017, 3:14 pmWell those changes definitely made a big difference, I got a good flower, I left $30 the same and swapped to $28=4, and did the changes in Inkscape, (DPI and number of greys) trying something a bit bigger this time.
Out of interest, when I asked at the kickstarter you were using 3mm Birch ply? If so, on a dark part of the engrave how deep roughly was is burning? Mines pretty deep and ends up almost 3D, just checking that is right because when doing a halftone on the old board it isn't the same (obviously)
Post the flower, I would like to see it 🙂
I didn't want to upload a tiny picture so just ran a 6x4" engrave. Took a while but I think the results speak for themselves... Very very happy with that!
I didn't flip the Y on this one, I hoped it would run bottom to top so I didn't have to clean smoke off it but it didn't.
Do you know if there is a way in CNCjs to run it bottom to top?
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Hi Tim, that’s really stunning! I’m impressed. You could flip the picture in inkscape or install an endstop flag in the k40 and home y in opposite direction (either turn the y axis connector ofr change the dir option in grbl firmware via a $ setting). Well done.
Quote from Guest on December 31, 2017, 12:55 amHi Tim, that’s really stunning! I’m impressed.
I know right, that really is the best picture engraving I have even gotten from my machine!
Very nice.
Some good information on here too.
Hi Tim,
After I finally got my K40 running again I used your rose for my first test. It's small but it came out good - thanks for a great test photo.
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I love how yours has caught much more detail in the background, I wonder if I had run it with a touch less power if I would have gotten the same... Hmmmm
Tim, it depends on your speed setting (800mm) and $30 (default 2048) PWM laser range config. If these settings are different and the wood/tube age you get different outcomes. In the wood supply from the same vendor, I had big differences!