Lithopane Cutting Depth

[davemartin88]

I've had some good success with lithopanes in .25 inch Corian with a lot of help from this forum. My final cutting depth has been .12 inches leaving about half the material. I was looking at some of the tutorial information again and seems that cutting depth is ending up at .2 inches leaving only about .05 of material. Will set up a test to give it a try and see how much of a difference the added depth will make but was wondering what others were using as their final depth.

Second, I've been using a plunge depth of .06 inches for my .125 or .0625 cutting bits and a single toolpath for the lithopane. Where needed, the router makes a second pass/cut and I haven't been using a separate roughing toolpath. It seems to me that as long as the plunge depth is set to a safe value that allows the single tool path to effectively take out the material in smaller bites where needed, it's about the same as doing a roughing and finishing path, am I missing something? Guess I might be sacrificing a bit of cut time for what I think is more simple but thought I'd ask.

Thanks to all that answer questions and offer assistance.

[NormanAlbert]

Hi: Most of my lithophanes are in the 5 to 6 inch square size and the corian thickness is .20 and I cut to depth of .15. I also use a .0625 tapered ball nose 4 flute up spiral bit in 1 pass feeding at 30 ipm. The Z drive dictates the total speed of the cnc so a faster speed setting really doesn't happen. I use a thicker corian on larger picture sizes up to .25 and plan on leaving .05. Still using the tapered .0625bn in one pass. The ice white corian does not make a good litho, use off white. Norm

[davemartin88]

Thanks. All the Corian I have used so far is .25 thick- sounds like I could try a bit deeper to see how it looks. Do you use the thinner material for the smaller items to decrease the weight? Will make up a test today and try to carve to a .18 or .20 depth. The Corian material I have is Glacier White which is an off white and seems to show details well. Thanks for the feedback.

[bill565]

The stock I have is about .256 thick on average and I always take it down between .20 or .21 depending upon the subject material. For extremely light ones, I tend to go just a bit deeper to get the lighting desired. Otherwise I tend to keep it around .05 remaining at the lightest point.

Good luck with the testing.

Bill

[dhellew2]

I cut lithophanes with the table set as the reference point then limit the cut to .030" above the table. The table is planed with the router/spindle so it is perfectly flat.

Corian/LG-Himax/Avonite are seldom uniform in thickness so it's not a good idea to use the top surface to set the tool.

I cut the entire depth in a single pass using a 5/64" or 1/16" bit cut at 135°.

This works without breaking the bit because the first cut is a plunge hole; the rest of the cuts are an 8% step-over cut, and as long as your bit can cut to the necessary depth.

I use 3-flute spiral bits made by http://www.cuttingtoolsource.com

The taper from the cutting size to the 1/8" shoulder is a cutter so at the worst there will be a slight taper around the edge, not one that you can easily see.

You may find the attachment useful.

LITHOPHANE instructions.zip

(1.9 MiB) Downloaded 421 times

Dale

[davemartin88]

Here's a new lithopane cut to a depth of .20 in a .25 inch thick piece of Corian. I have mixed feelings, think I'm seeing better contrast but has what looks a bit "grainier" to me? Could be the photograph but I did another one of a water scene that had the same look. From further away, these look better but at a closer view, I think I liked those I did at about .12 depth better but I remain amazed at the amount of detail these show?

I'm taking this one to a Sheltie Rescue group picnic tomorrow to be part of a silent auction. The winner can take this one or send me a photo of their own dog for carving. Maybe try about .15 next time just to see if I notice a real difference. ! I also used the same photo and made a 2" x 3" version for a night light for the auction. Thanks for the feedback.

[PaulRowntree]

This looks very nice to my eyes. The background is interesting because it doesn't distract from the subject.

[tonydude919]

Dave,

I never go deeper than .12 deep on my lithophanes and they look fine. The dog came out nice.

Tony

[martin54]

Dave, I can't comment because this isn't something I have tried myself but surely the only way to know for sure is to take the same image & same type of corian to produce 2 or 3 with different cutting depths so you have a direct comparison.
As with most types of graphics though resolution & viewing distance will play a big part.

[calgrdnr]

What bit are you using ? "grainier" is lack of resolution( Assuming picture is not grainy to begin with .
Due too large of bit for subject being machined .
try a vbit with angle 45 or less 30 degree tell software it is 0.031 ball nose works great
it will take 2x's as long as 1/16 ball nose.

leaving 0.004 ( very fragile) will give you better whites and 0.25 better dark ( black)
The difference will give better contrast... and 3D effect.

Vbit you can cut as finish pass only or if using PVC tell it to cut full depth .

have fun

Kent

[creek]

Trying my first Lithopane. My material is clear I also have bronze but the thickness concerns me. It is only .093 thick. Has anyone tried one on something this thin if so what type of bit do you use and what depth should I try? It is a black and white picture I want to carve.
Thanks for your help in advance.
creek.

[tonydude919]

Creek,

What material are you using that is clear? We use corian for lithophanes.

Tony

[martin54]

A lithophane won't work with a clear substrate no matter what it is made of, all you will see is the light shinning through from the back.

[NormanAlbert]

Hi: You'll probably find that a picture of less detail comes out better the thinner the overall corian is. Say .20 instead of .25. I also try to eliminate the back ground as much as possible in photo shop. Sometimes it's easier to blur the back ground for smoother z transitions. Norm

[creek]

Creek,

What material are you using that is clear? We use corian for lithophanes.

Tony

Thanks