Sorry if I'm clogging up the forum, but I'm working hard to dial in my parameters on lithophanes. At least I'm giving lots of folks something to look at.
This beach scene (a photo for an old girlfriend's Maui vacation) didn't come out nearly as well as I'd expected, mainly because the difference in depth of the carving throws off perspective, at least IMO. The contrast, especially the face, looks odd at too many angles. I actually prefer the shallow results I previously got in .125 acrylic! What's interesting is that this is the first piece I've done where the photographic image of the work looks better than the carving itself.
This was done in 1/4" corian, cut to .21" in a single pass with a 30° bit. For the first time I deleted the rapid clearance gap using notepad, after first changing the last Z-clearance to .1" so it wouldn't be deleted on the search/delete. Total time to cut 4"x3.75" was just over 3 hours. Estimated time was 1hr 17min. This is still in line with the roughly 240% over estimate I was getting before, so I don't know how much effect eliminating the clearance gave gave me.
There's a bit of graininess because the original photo was too small, so I had to enlarge it (I used Kneson Imagener, made specifically for enlargements, which generally gives a better result than algorithms in other programs). I'm wondering if I'd get enough contrast if I used VCarve Pro to cut out a pocket and then do the carving with less depth.
At first I thought the bit I used (photo #2) might have affected quality. While both bits in the photo are 30°, the one on the right is very fine, as the tip of the shaft is cut in half, while the left bit, which I used for the first time, is square cut. (I chose the new bit because the tip of the other broke when my Z-axis didn't stop on command going down. The difference isn't visible, but it isn't as insanely sharp as before.) However, when I compared the bit profile to the cutting depth, there doesn't seem to be any significant difference.
Question of depth perception in lithophanes
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- Vectric Wizard
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Re: Question of depth perception in lithophanes
Clean the litho with a fine stainless steel ( NOT brass ) tooth brush like brush, and liquid dish soap .
it will clean up the Klingons and look Much better then the picture posted .... IMHO Kent
please repost after you clean it
it will clean up the Klingons and look Much better then the picture posted .... IMHO Kent
please repost after you clean it
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- Vectric Wizard
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Re: Question of depth perception in lithophanes
If itis just the tip les then .03 you are ok at least all mine have turned out finedifference isn't visible, but it isn't as insanely sharp as before
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- Vectric Craftsman
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Re: Question of depth perception in lithophanes
I'm not throwing way the tip-less bit; it's still about as sharp as the 4-sided one. Considering these cost me about a buck apiece on ebay, though, I'm not too worried. It's the $28+ bits I hate breaking!
Off to work; no steel brush here now, but I'll see what I can do to clean this up first chance I get. The depth of cut/contrast on the cheekbone still throws me off though ....
Off to work; no steel brush here now, but I'll see what I can do to clean this up first chance I get. The depth of cut/contrast on the cheekbone still throws me off though ....
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- Vectric Wizard
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Re: Question of depth perception in lithophanes
I use vee bits to cut lithophanes all the time but there is one disadvantage. It is not possible to machine a vertical wall.Stickman wrote: The depth of cut/contrast on the cheekbone still throws me off though ....
At best the wall will have a slope equal to half the bit's included angle.
For most photos this is no problem, but sometimes it will show up on a hard light/dark transition. Will give a halo sort of appearance.
I sometimes have this problem around the eyes. Transition from white of the eye to the iris/pupil. Can make for weird looking eyes.
Of course this will be less pronounced with a 30 degree cutter than a 60 degree.
Greg
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- Vectric Craftsman
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Re: Question of depth perception in lithophanes
Hmm, so has anyone tried a 20° v-bit? Probably a bit extreme, and would take that much longer ....
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- Vectric Wizard
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Re: Question of depth perception in lithophanes
I guess the ideal would be very small ballnose.
I don't have any.
As I say though, for most pictures a vee bit works perfectly.
They are also fairly robust. I never do a roughing pass on a lithophane.
Greg
I don't have any.
As I say though, for most pictures a vee bit works perfectly.
They are also fairly robust. I never do a roughing pass on a lithophane.
Greg