lithopane lights

[Jackie McGowan]

Hello all, I'm pretty new in the lasering bus. and have learned alot from the forum. Thank you all. I have not worked with acrylic at all yet but... I was wondering if anyone knows of an acrylic material that may be able to be 3d lasered (or just lasered) with a photo to have the effect of a lithopane when back lit. I have seen this on a website, they don't say that it's lasered they say "special process" but they are saying it's an acrylic material (as aposed to the real porcelain lithopanes). Even it there "process" Is not lasering, I wonder if lasering would work. It would have to be sort of an off white color material. Does anyone know anything about this or have any ideas on what material I might try?

[Shaddy Dedmore]

I think I know what you're talking about. I've seen a guy use a CNC router to 3-d (as in, just a relief type 3-d, not a free standing object), and he used a sheet of corian. It was white clolored, and looked like crap, then you held it up to the window or light source and it looked amazing. Really impressive.

Acrylic is cheap, buy some cast acrylic and see what it does. It can't do what that router did, but you may like the results just the same. Someone around here has done some photos, then edge lit it (LED's in a little stand), and the pictures looked pretty good.

If you have a laser, it's only a matter of time before you use acrylic anyway. I've had good luck with Delvies Plastics. If you're etching, use the Cast for that frosty look.

Shaddy

[Jackie McGowan]

Shaddy, Thanks for your input. Is it ok to give the websites where I've seen this stuff so you all can see what I'm talkin about? I've found two sites one says they use an acrylic material and the other says a polymer based material (they seem to look the same and sort of translucent). I don't want to give sites unless I know it's ok (not sure of forum rules) but would love for you all to see. I will be sure to try the plastic you suggested though.
Thanks again!;)

[Rodne Gold]

Lasers do horrible things when doing 3d - or true continous 2 1/2 d
It's almost impossible to get smooth surfaces and you end up with a lot of crumbly surfaces with ridges etc.
There are strategies to smooth them , but it cant come near the type of stuff I can do on a cnc overhead router or smaller engraver.
I have done what you describe , I called it a cameo cos I didnt know the right name , used white acrylic for it and used an overhead router. It took literally days to do a small one of these (i think it was 6x4) as the stepovers between engraving passes was exceptionally small to get the smoth surfaces needed.
I only went in 3mm deep at the deepest !!
The laser will do "stepped" 3d a lot better than continuous , IE lets say 6 different discreet depths on a panel , however there is still the ridge problem.
What MIGHT work , albeit we have NEVER done it on acrylic but in glass is a multiple depth sand carving.
What you do is apply a polyester vinyl resist to the acrylic and selectively peel off sections and blast.
For example a leaf with veins can have a mask cut with the laser so you can separate the leaf from the veins , you pull off the leaf setion and sandblast and then after you have some depth in leaf , you pull off the mask of the veins and continue blasting. What happens is the leaf gets deeper with the continued blasting and the veins stand out. If you backlight this , the deeper leaf will allow more light thru and the veins wil be darker , the stransition between the leaf and veins is smooth , not sharp and the blasted surfaces are smooth too.

[Keith Outten]

Hello all, I'm pretty new in the lasering bus. and have learned alot from the forum. Thank you all. I have not worked with acrylic at all yet but... I was wondering if anyone knows of an acrylic material that may be able to be 3d lasered (or just lasered) with a photo to have the effect of a lithopane when back lit. I have seen this on a website, they don't say that it's lasered they say "special process" but they are saying it's an acrylic material (as aposed to the real porcelain lithopanes). Even it there "process" Is not lasering, I wonder if lasering would work. It would have to be sort of an off white color material. Does anyone know anything about this or have any ideas on what material I might try?

Jackie,

I have seen a couple of lithopanes at the ShopBot facillity in Durham North Carolina that they did on a CNC router and they are very impressive. I haven't heard of anyone making lithopanes with a laser engraver, I guess it is possible but seems difficult to get the same resolution that is possible via routing. There are some links on the Net concerninig lithopanes but very little information on how they are made or materials that work well. I think most people use white acrylic these days, although Corian works it is generally less translucent than many of the acrylic materials available these days.

As Rodne mentioned the time required to route a lithopane is lengthy and I think that many people refrain from making them because of the routing time. If you find that they can be made via engraving let us know, there are a few people here that would be interested in any information you can find on the subject.

[Kate Raap]

My dad has done a few of the lithopane pictures with his cnc router. It's not white acrylic that he uses, but it's a type of plastic. I have tried the lithopanes with the laser, it doesn't look good. I have the universal laser and it has the 3d driver in it, does awesome things with pictures on clear acrylic and edge lighting them. I will see if i can find the pictures of our lithopanes and post them on here for you to see. They aren't a hot item around here though so we rarely have a new one.

[Mike Kelly]

Jackie, this is an example of a lithophane that Bill Palumbo did for me on his ShopBot. Here is his website for more info. http://www.baycraftdesigns.com/

You can see a backlight on and off example of what he did for me on the third page of this link. I did the frame and light.

http://www.sawmillcreek.org/showthread.php?t=13974