having fun here...

[Don Corbeil]

...with the new trotec s300. Have been doing some practice work on wood, thought I'd attach one pic here.
This was a tiff of an MCEsher print, "ripples in water". I have always been a big fan of his work, and it looked like a lot of his work translates well to halftone laser engraving. In trotec job control process options, this was done under relief setting, 500 dpi, floyd steinberg dithering, 100% power, 85 speed, 500hz.

Anyone know much about the different choices in dithering found in trotecs print setting page? I notice there are different choices for 'halftone' settings in the pull down box, such as 'ordered dithering', 'stuckey', 'jarvis', 'floyd steinberg', etc.. What setting do you tend to use for halftone relief engraving?

Really enjoying this new tool!

edit* added original print

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[Mike Null]

Don

That looks great. Did you consider inverting it?

I generally do not do photographic images so somebody with more experience will have to answer your question.

[Don Corbeil]

Mike,
Thanks. This was actually done from a print (I believe a linoleum cut) by mc escher. He was a dutch graphic artist who was a master of creating geometric patterns with animal/landscape subjects that blended into optical illusions.
Here's another print of escher and my engraving of it (bats&angels). You can see that I didn't get the white/dark balance good enough to balance out the depth of cut. I think I need to adjust the gamma a bit more to try to get the darker and lighter aspects more balanced.
His work is sure fun to experiment with to learn the laser abilities a little better. I just need to make sure I have enough scrap wood on hand :)


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[Dan Hintz]

Don,

That's an image that would do very well as a 1-bit (no dithering) with a high power to really dig deep. If you still want some shading in there to keep the sun, try two passes, one at high power for depth (with the sun removed), then a second for shading (everything other than the trees and ripples). A bit of extra work, but I bet it would really pop.

[Don Corbeil]

Dan,
thanks! I will try that procedure.
So, if I understand correctly you are saying that in the 'processes' part of the print choices, select black/white (1 bit) instead of any dithering options?
And then mask out (deselect) certain parts when I burn the others? Sorry, still learning all the capabilities of the job control...

[Mike Null]

Don

I would also bring the photo into Photopaint and work on the grays, darkening them a bit.(the angels photo) I think you have produced a very good example.

I suggest you photograph everything so you have a reference. Thanks for posting these.

[Dan Hintz]

Dan,
thanks! I will try that procedure.
So, if I understand correctly you are saying that in the 'processes' part of the print choices, select black/white (1 bit) instead of any dithering options?
And then mask out (deselect) certain parts when I burn the others? Sorry, still learning all the capabilities of the job control...

Sounds like you have the idea. Split it into two images... one that provides a sense of texture (the high power run) and one that provides a sense of visual depth (a lighter power shading run). The ripples/trees should be run as a black/white image, basically cutting the wood really deep. The sun won't be touched, but the rest should be run as a 1-bit dithered image, which will provide some shading to everything. I bet it would look really sharp. If you wanted a spot of color, add some yellow or orange dye to the sun, or go really crazy and add some light blue to the water.

[Don Corbeil]

guys, thanks for the feedback and encouragement. This has really been fun testing the abilities of this laser. I'm going to work on both of these escher prints some more, as per suggestions. I'll post results back later. It's funny, since I got the machine, I am finding it hard to get to sleep at night with all the different ideas and potential settings variations running through my head :D

[David Somers]

Don,

I am afraid I am not familiar with some of those dithering patterns so I can't speak to their strengths.
But, if you have enough play wood around why not do up a one of your images in a grid pattern, but with each square of the grid on a different layer. Then run each square onto the same wood as a different job with a different dithering pattern and then have a record of what each does? Maybe do a set for the graphics like you have in the MC Escher prints, and another with a photograph. Unless someone else out there has already done that and would care to share?

Glad you have having such fun!!!

<grin>

Dave

[Don Corbeil]

David, great idea to help see a side by side comparison.
I just returned from the local lumber yard, and picked up a new batch of assorted scrap wood. Oak, maple, poplar, pine, etc.. I think it should keep me in the shop for awhile.

[Steve Busey]

I like that ripples pic. I'd love to try that in marquetry, vs engraving.

[Don Corbeil]

Steve,

Yes, that would be very nice with a marquetry inlay pattern. I could see some curly maple and darker hardwoods working well in there.

Here's another iteration of the image following the above suggestions. I broke down the image into three layers, then engraved those at varying depths and with both an x & y engrave orientation. It did pop out nicely. I had to be careful with the smoke residue adhering to the lighter parts of the image during the deep burn on the tree outline. The order of engraving was important, and I got rid of most of it, but I still had to do a light 'cleanup' engrave on the moon reflection to reduce residue. The darker branching benefitted from a deep cut that charred the surface a bit. The natural grain in the wood darkened that lower section in a way that I would prefer to avoid in the future.


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[David Somers]

Don,

Just curious, how long did that last version take you? It looks very good though. You really got depth in that!

Dave

[Steve Crawford]

Don, can you tell me the individual settings you used for each layer please, and what parts of the image those layers were? I'm very impressed with how the latest one you did compared to the first image you posted, a vast improvement. Your first one is more like the results I've been getting when doing this kind of thing and so I'm very keen to improve. Also what do you mean by "both an x and y engrave orientation" and "cleanup engrave"? Sorry for the questions but as a new S300 user myself I'm keen to get the most from my machine.

[Mike Null]

Steve
Your Trotec can be set to engrave in the Y axis.

Don
Nice work. I use diluted Pinesol or similar cleaner to soak up the residue on wood. (don't rub if it"s unfinished wood)

[Steve Crawford]

Steve
Your Trotec can be set to engrave in the Y axis.

That's interesting, I was not aware of that, is there any advantage/disadvantage? I suppose it changes the motors that are then doing the brunt of the work, is there any repercussions to that?

[Scott Shepherd]

That's interesting, I was not aware of that, is there any advantage/disadvantage? I suppose it changes the motors that are then doing the brunt of the work, is there any repercussions to that?

There are advantages and disadvantages to it. For the right job, it's an amazing time saver. Imagine text engraved vertically, 15" long or so. You can engrave that in a minute or two instead of having it engrave 15" down the table. It is slower in the Y-Axis. It's not the normal speed you see the X-Axis working, so in that sense, you wouldn't want to just normally engrave in the Y-Axis. But, for the right job, it's an amazing feature and one I think very few people are even aware of.

[Chuck Stone]

I had to be careful with the smoke residue adhering to the lighter parts of the image during the deep burn on the tree outline.


If you do it in separate passes and cleaning between passes, that will help.
(provided you can get the piece back in the same position)
Also consider spraying the raw wood with lacquer before running it. That way
you can easily clean the residue with a damp cloth. Tougher on lightly engraved
wood, but you can still do it. If you run your lightest pass last, it should be a
piece of cake.
Doesn't have to be lacquer.. I also use acrylic spray or shellac

[Don Corbeil]

Steve,
Unfortunately, since was just trying things for the first time I didn't save the settings in job control (or write them down), but the key for me was to have the image file reduced to three colors that I sent through to job control, and then alternatively use x and y engraving orientation. The colors were assigned individually to the tree area, the water, and the moon reflection. There's a color setting in job control processes, and that was what gave me all the control over the depth. It made a huge difference in being able to run a pass on a specific area, evaluate, and then run again if necessary. I did a first pass for the trees only, digging deep (probably at 100 power, 65-75 speed, 1000 Hz). I then did the water area after that, at less power and speed, then lastly the moon, mostly untouched. The moon as I mentioned had a lot of residue on it from the previous burns, so I did a very light cleanup pass on that color only, something like 15 power, 90 speed. It was just to take off enough residue where I could lightly sand it. The visual char in the tree areas in the first pass actually helped the rest of the layers pop out.

What I call y axis engraving is actually found in job control under Plate>Plate Setup> Engraving Direction> Portrait

I discovered 'y axis' orientation engraving when reading through the manual, and I noticed that it is used also in the 'layer' settings in job control process. The layers process will allow you to set the total number of passes in the job, and it will than alternate between x and y engraving on respective passes. One thing I noticed is that when engraving on the y axis, you really have to slow down the speed (and power accordingly) for smaller pieces because the machine will vibrate/jiggle considerably otherwise. When I first ran a y axis engrave, it was at a higher speed, and the machine was jiggling so badly that I thought it might move the piece. I quickly learned to now slow down the speed and power accordingly to reduce this effect.
I think I see a clear advantage in using alternate x &y engrave orientation for relief engraving. It tends to make the result more crisp.

Dave, I didn't save the settings (I do need to record these things in the future), but I would estimate the engraving alone was probably around 10-15 minutes for all colors combined. However the time I spent in corel trying to learn how to get the image to the place where I wanted it, now that was another matter. It takes me a lot of time in the software at this point because I am just learning corel.

Mike, I will try the diluted pinesol for residue cleanup, since this happens quite a bit with the deeper engraves, and cutting.

[David Somers]

Don!

Thanks for the time estimate. That is actually much faster than I envisioned for something that engraved that deeply. But then I still have no frame of reference other than my trying to engrave things with my hand help laser pointer. Amazingly inefficient, even if I hold a magnifying glass in front of it. <grin> Guess I am gonna have to actually buy a laser at some point huh?

Thanks again for showing the progression on that piece!