Candlestone or Corian for lithophanes?

[kristenanne77]

I was looking for corian for making lithophanes, and I saw a possible substitute material on ebay called candlestone.
What are the differences between the two materials when used for lithophanes?

They advertise that candlestone is better than corian.
Also say
"Candlestone allows you to use a lower model height and you still gives you a better image. This can dramatically lower the time it takes to cut a lithophane since the total Z movement is much less. "

Not really sure how to read this.
Does "lower model height" mean that with candlestone lithophane "negative image" is cut thinner than when using corian?
I would think that if is thinner, then it would take longer to machine and there would be greater chance you could accidentally cut through the material.
I would prefer to use the material that would give me a greater margin of error so I don't accidentally cut through the material.

thanks
K

[dhellew2]

Candlestone is less translucent but with a good light source produces extra contrast for superior lithophanes. The only downside is that Candlestone is somewhat brittle and does chip easier than Corian/Avanite/LG-HiMax, etc.
Dale

[Xxray]

Candlestone is a good material, I would not pay more for it than corian though.

There is little margin for error no matter what you use - If you don't cut deep enough the image will be too dark, if you go too deep you will break through the surface and ruin the project. For a .25 workpeice I would go .21 deep and rarely have problems with that margin. Of course, that all depends on having a very accurate Z measurement and a nice level table.
Also important to check thickness, measurements for sheet good like this are nominal and need to be checked individually - So if you don't have digital calipers, get some.

BTW, not cutting deep enough is recoverable by simply sanding the uncut side until you get proper depth. You can use a belt sander, orbital sander or [best of all] drum sander ,,, Just use a fine grit with multiple passes, else sanding marks might be visible.

[Trock]

Hi,
Here is a crazy test I did with basic engraving stock. I use it to make labels and name plates. Very Cheap stuff.
It is .06" material. It took a long time to carve but happy with the results. It's about 3" square.

I plan to make a little frame for it. It has great contrast, almost like a black and white photo when lit well.
Just thought I would share.

[kristenanne77]

Now I noticed yet another substitute material for corian called Avonite.
Anyone know about the qualities of this stuff?


Thanks
K

[IslaWW]

kristenanne...
There are a bunch of "Corian clones" on the market. Each with slightly differing chemical properties and translucencies. Most will cut slightly different than the original. Some may give you satisfactory results, but you will have to test each and adjust feeds, speeds and cut depth.

[dhellew2]

Avonite and LG-HiMax behave and look just like Corian. Unless they are marked you cannot tell the difference.

The best way to guarantee lithophane results is to include the following steps.
Plane a flat spot on your table with your CNC
Make certain the bottom surface is completely flat against the table
Set your reference at the bottom of your lithophane [if you have a touch plate set your offset using the planed table

Corian and others are not consistent in thickness. Using the top as reference can result in unsatisfactory results. I set my gap below model at .03 and on my machine get consistent results.

Dale

[molechaser]

Solid surface materials are similar but not necessary exactly the same. My goal with lithophanes is to get a wide range of tones, from light to dark, within a reasonable model height (Z height). If the material is too translucent your image will look washed out or you have to increase your model height to compensate. The downside to increasing the model height is more distortion in the lithophane image so you need to be more directly in front of it when viewing. If you are cutting with a tapered or v-bit bit you also have to consider how much you are affecting the image based on the side angle of the bit. The larger the Z distance, the more you are cutting with the side. One last thing to consider is the size of the lithophane. Smalll night light sized lithophanes look better with a smaller model height.

I use a model height of around .13” based on my machine resolution (.0005") X the 256 shades of grey in the image. For night lights I will use .12" model height and for 5"x7" and larger I will use a .13" or .14" model height. Candlestone material works very well within this range and provides contrast that will compare to .18"+ in Corian.

I also find that the original image is more important than anything else. You need a good, sharp image to start with and I suggest converting to black/white first. Some great color images just don't work well for black/white or may need significant adjustments. I use Photoshop and Nik software Silver Efex to convert to black/white which I then import into Aspire instead of the original color image. I don't worry too much about resolution of the image since the stepover is going to limit the "resolution" of the lithophane. I use a stepover of .0065 so I figure I need about 150 lines per inch in the image I import.

[dhellew2]

Molechaser is correct, the photo is everything.

The attached pdf contains photos and examples as well as step by step instructions for lithophanes.

Dale

LITHOPHANE instructions.zip

(1.9 MiB) Downloaded 1089 times

[thefixerdude]

I got some scrap LivingStone from a local counter top shop. It was .475 inches thick according to my cheap digital calipers.

It looks a lot better in person.
It is 11x14 (9x12 carved)
Cut in one pass with a 1mm diameter tapered ball nose. 12% stepover. took about 6 1/2 hours to carve.

Chuck

[DanB]

That looks really good from just the photo alone. I have not personally worked with this just yet since I only installed my Cut2D and PVC package yesterday, however at the shop where I consult in the evening I stumbled onto some material that one of the guys blurted out "Oh, that's Corian". Well after a little investigation I was told it's "acrylic stone" or solid surface material. Feels heavy and dense, is 1/4", and is an antique white color so you know it has a beige tone to it. I know most prefer glacier white etc... but this is scrap material so who's to complain about something free to practice with eh?? It would just mean a warm tone to start similar to using daylight film under tungsten lights. Ok many probably not familiar with the term "film" for a camera...

I cut some of this up on the table saw to 5 x 7 pieces and left the other larger for now. Also have a couple of 2" strips that I expect will make nice quickish test pieces.

I took down some notes from the purchase order but don't have the notes with me today. Later I'll do some checking along with calling the vendor it came from to get the skinny on the actual product name and spec sheet if possible. I do know it's pricey like a sheet of corian and it comes in odd sheet sizes unlike standard 4 x8.

Appreciate the posting of the process zip file. Will store that away for when I actually get to work with this some.