A question on Lithophanes

[Nappy1]

I have made several Lithophanes in the past week, since I got Photo V.
I like the results but I have one problem.
I set up for .250 material thickness, and max cut depth of .230. The cut never comes out .230 deep. Usually it is only.125 deep.
So what am I doing wrong?

[dighsx]

Is the .125 at the deepest cut? Also what bit(s) are you using. Have you looked at the tutorial on this page, there's a lithopane tutorial torwads the bottom of the page: http://www.vectric.com/WebSite/Vectric/ ... _tutorials

[Nappy1]

I measured the depth at the lowest point. It was only .100.
I used a 1/8" ballnose.
I was able to make it right by making 2 additional passes of -.030 and -.080 which took the thinest point down to .020 or there abouts.
The litho looks great but I should be able to make the same results ( I think) with one pass.
Right?
I did look at the tutoral but the audio is not too good.

[dighsx]

What do you have entered for the 'Carving Max Depth' in Step 3 (Set Cutting Parameters)? You should be able to set how deep you want it to go there, in this case you'd want it to be 0.230 inches.

[Tony Mac]

Hi Nappy1,

What you are probably seeing is that the deepest area to be machined (the white pixels in the image)
are relatively small in comparison to the size of the 1/8" diameter ball nose cutter. The software ensures
the cutter doesn't 'gouge' into the darker regions of the design / image, so the cutter never actually
cuts to the Carving Max Depth.


For example, if an image only contained 1 white pixel this would represent the lowest point for the
Carving Max Depth. But the cutter would never actually cut to this depth (unless that 1 pixel represented
an actual size greater than the cutter diameter.

When cutting small lithophanes with a relatively large diameter cutter, the chances are the depth will not
go as deep as you had specified in the software.

What size is your design?

Also, a Carving Max Depth of 0.230" is likely to be to great
(If this is too large the dark regions of the design will be very thick and won't allow any light to pass through)

I would suggest, setting the Carving Max Depth = 0.100"

Rapid Clearance Gap = 0.250"

Calculate & Save the Toolpath

On your machine set the Z0 origin to be -0.130" into the material surface
(set the cutter touching the material surface = +0.130")

This drops the toolpaths into the material by 0.130" and machines to an extra 0.100" Carving Max Depth.
Leaving around 0.020" on the base / back of the material.

I hope this makes sense and let us know if you have any questions.

Tony

[Nappy1]

Now you guys are really confusing me, well somewhat anyway.
Let me start out by saying that i have used artcam to make lithos before taught to me by Doc Palumbo, you may know him.
I like the results of Photo V better though. Maybe its my thought process. I would rather make one pass with a 1/8 ballnose at 20 ipm that 3 passes with adjustments in between each pass. I choose my photos to be balanced in gray scale, not color. sufficent white ( or very light areas), light to dark grays, ect.
I will take some pictures and post them after i finish my reply.
1. I set max carve depth at .230. This allows .020 of uncut back to the material.
2. The designs are anywhere from 5" x 7" to 8" x 10".
From Tony"s description, to set the carving dept to .100 and then lieing to the machine about the Z height I have already done that. It worked. I just thought it wasn't the right thing to do.
I can run a 1/8" ballnose at 100ipm and cut 125 deep, so the tooling isn't an issue.
Don't get me wrong. I am not dissatisfied with the program. It works better than what I was using. I just expected it to follow my instructions when I told it to cut the white areas at .230.
Photos to follow.

[Nappy1]

Here are 2 samples.
The one with the baby is a 22 year old video tape capture. the other is a stock photo from a cd.
Both done on 1/4 corian.

[dighsx]

Both of those came out really nice.

[Nappy1]

The photos don't do them justice. Honestly it was easier than the other program. Like I said it just confused me.

I would really like it if we could import something like Vector Art Boarders around it. Then that would be cool.

[Tony Mac]

Excellent lithophanes Nappy1.

VCarve Pro will import Lithophane toolpaths from PhotoVCarve and Vector Art borders
so they can be positioned relative to each other. Each toolpath can then be previewed
to check they will cut in the correct position, then saved.

Take a look at the Video Tutorial and pdf document that show PhotoVCarve designs being imported into VCarve Pro,

http://www.vectric.com/vcarve-download/ ... orial7.exe

http://www.vectric.com/vcarve-download/ ... _Files.pdf

Tony

[Nappy1]

Well I know i'm going to have to buy it one of these days but I need to wait. Just too many things on the old wish list.