latest photovcarve test

Dan Noren

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was back at it again yesterday. finally got time to start this after i dropped the wife :blah: off at church. here i was thinking, four, maybe 5 hours tops. i had set the depth at .08 inches, the speed at 10 inches/minute, with an overlap of 10%. oh yeah, i almost forgot, it took a little over 11 1/2 hours to complete, and this was only a 5" x 7" picture. i changed the depth, and speed today, to .04, and 90 inches/minute, and it started to dig deep early on. so, the next attempt will be at 20 inches per minute, with a depth of .05, and see how long that takes. all i can say is, is that it is a better result than the earlier attempts with this software. almost forgot, i was using a 3/32" ball nose bit to do the cutting.
 

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It's good to see you back to testing your system with PVC. I hope you find all of the issues.

Keep in mind that the gcode you sent me from your software started as follows:
G20
G0Z0.2000
G0X0.0000Y0.0000S12000M3
G0X8.9887Y0.0113Z0.2000
G1Z-0.0300F75.0
G1X8.9802Y0.0053Z-0.0296

With a maximum depth of cut of 0.03" and feed rate of 75ipm, that file ran in just over 1.5hrs and that was about a 9" by 11" cut. I used a 1/8" 30° engraving tool that I had filed the tip to about a 0.4mm flat.
 
needless to say, i'm going to have to tweak this one a bit. i'm going to have to make the hair on the girl a shade or two lighter than her face, as the software interpreted it as being the ultimate dark (her hair is black), and cut it deeper than her face. i figure that if i get it about the same shade, the face and surrounding hair will be on about pretty much the same plane when it gets interpreted and cut. i may boost the feed rate from 10 to 20, or 25, and shallow out the depth of cut to try and improve the time it takes to make the picture. if i'm stuck at 11 and a half hours, i will definitely start at a much earlier hour than 3 in the afternoon.
 
how did you get it to .4mm flat bill? that's a skinny cat hair split twice. i was thinking a quick run across some us forest service outhouse paper (not too bad if you don't pay too close attention to the slivers) would work.
 
how did you get it to .4mm flat bill? ...

I used a small, fine metal file and held the bit as I raked it across the file. Using some magnifying glasses, I kept checking it until I could see it was not quite 0.5mm.

I tried that approach to PVC carving after reading a lot of posts on the Vectric PVC forum. Of note is a thread I referred you to before: LINK. One post contained the following:
For small detailed pictures i use 0.2mm V-bit's
For medium 0.3mm
And the large i use 0.5mm
I also have the line spacing as vide as the v-bit i use so i remove all the material and get a 3D-surface corresponding to the picture.


Using that bit gave me a smoother cut than a pointed v-bit, of course, but wasn't digging in like a larger bit would. The file I cut for you as a test is the highest feed rate I've ever used and it ran clean the entire time.
 
ok, this one is driving me to distraction (and not a very long road on that one). no matter how i set it up in pvc (including your set up bill), i still wind up with the problem concerning the girl's hair. it still wants to carve it way deeper than her face. not too sure what to do about that one. any ideas on how to at least bring the level of hair up to her face?
 
ok, this one is driving me to distraction (and not a very long road on that one). no matter how i set it up in pvc (including your set up bill), i still wind up with the problem concerning the girl's hair. it still wants to carve it way deeper than her face. not too sure what to do about that one. any ideas on how to at least bring the level of hair up to her face?

PVC is doing what it's supposed to do - create a halftone image from the information it's given. It does that by cutting deeper on darker colors; whites are left at or near the level of the surface. If you look at the examples on the PVC forum at Vectric, you'll see that. It appears that others deal with it in one of two ways: use a v-bit that leaves the lines but makes wider grooves that hold more stain, or tweak the photo in some way if necessary.

One thing that came to mind in your case is to make the background dark; i.e., use PhotoShop or similar software to outline the subject(s), then make the background dark or black. Against a black background, the hair color would be lighter and not cut so deep. I can't say that would work for sure because I haven't done it.
 
On further review, as they say...

I've spent a little time on the Vectric PVC forum to learn more about its functioning.

What you're trying to do is a relief rather than a halftone, which is what a lot of folks do, apparently. But, when you do that, the only way PVC has to deal with the image is to cut darker parts deeper than light colored parts. So, as I said above, you need to use something like PhotoShop to mask different areas to change their luminance levels.

In my work with PVC, I've been trying different bits and software settings to get a halftone image I like. I've tried different engraving bits as well as v-bits. There's no real difference between en engraving bit and v-bit as far as half-toning is concerned as I see it. Rather than cutting away all of the material, engraving makes wider grooves for darker areas and narrower for light areas all the way to no cutting for "white" areas of an image.

The distinction between the two methods is something it took me a while to grasp. When I finish a bunch of other things on my honey-do list, I'll get back to a couple of photos I've tried.
 
bill, last night at work i messed about with it for a few minutes with photodraw. i cut the hair away and made a negative of it, and pasted it back onto the original picture. now just waiting for the weekend to try it out. let it run while i'm sanding the towel cabinet.
 
Cool, Dan! Good luck with the modifications; it appears that's the only way to do relief photos. As I learn more about the ways to do haltone with PVC, it's getting better but I haven't spent much time with it yet. I have a couple of things I want to try by using relief carving.
 
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