LITHO-FRAME

thingiverse

Lithophane Frame. Backlit shadow box for lithophane display. This was my first attempt at framing a lithophane and also sharing a project. I decided to create a large 8x10” lithophane for a 50th wedding anniversary. There were a few hurdles but the results look good. I added detail on some of my mistakes and how I might improve things next time around. Print Settings Printer Brand: LulzBot Printer: TAZ 4 Rafts: No Supports: No Resolution: .1-.4 Infill: 20-100% Notes: I used Cura to generate the gcode. The lithophane was printed on fine mode with 100% fill. The layer height was changed to .1 so I could get a lot of shades (thicknesses) without using a lot of plastic or requiring a ton of light. I used natural ABS for heat resistance and translucence. I added a brim to help prevent warping. The lithophane for this frame should be 7.75x9.75" minus 1mm or so. For the frame components (the posted stl files) I used the stock abs fast settings with an added brim. Post-Printing Clean up... I had burnt bits of plastic fall off my hot end during the print. I should have cleaned it better before hand. Anyway, I dug the visible bits out and removed loose pieces of plastic. How I Designed This Some Project Details... When you open an image in Cura (cool feature) there is a dialog box that configures how it will generate the stl.I set the base to .7 so I could get multiple base layers before the image was printed (to help diffuse the light in thinnest layer). I set the depth to around 7mm. With the .1 layer thickness this gave about 64 shades of grey in the image. It's important the input image is pre-cropped to have the 8:10 aspect ratio. My tiny photo required a lot of touch up and the 300 dpi scan only yielded ~5 pixels/mm. One struggle was creating a balanced illumination. The leds are about 1.25” apart so I tried to fold/glue my strips onto the back at the same spacing. Because of the lens angle on the led you will get bright spots if the lights are too close to the lithophane. I tried a lot of things (diffusers etc) to keep the box shallow but gave up in the end. By keeping the lights about 1” back from the lithophane the lighting looks even. The frame itself sort of came together in a random fashion because I was learning as I went and the prints take too long to trash. The back that the leds glue to was originally going to replace the cardboard back that came with the frame. Because of the lighting problem (above) I printed the ~1” thick spacer that the back glues onto. Since lithophanes aren't an even thickness I also created a pocket for the lithophane to fit in the spacer (losing 1/4” off 8x10” size to still fit the frame). This provides a uniform thickness so it fits into the frame nicely (holding the outer clear plastic snug). I will drill some holes in the back to release heat. Possible improvements: Most of this would be easy to make into a single piece that holds the lighting and the lithophane. Next time around I will add tabs (or something) so it can be screwed into the frame (on this one I will use hot glue). Ventilation holes would be good addition. I decided to keep the led controller that allows changing colors etc via remote. It's glued onto the back which means the picture can't hang on the wall (goes into a stand – that could be printed). This controller could be housed inside the frame if it held a smaller image. Gluing the lights to the sides (so they don't shine direct on the back of the lithophane) may allow for shallower frames. Parts from Amazon ~ $17 - Swing Design Chroma Shadow Box Frame, 8 by 10-Inch, Walnut ~ $27 - WenTop® Led Strip Lights Kit Non-waterproof SMD 5050 32.8 Ft (10M) 300leds RGB 30leds/m with 44key Ir Controller and 12V 6A Power Supply ~ $22 Mitus ABS Filament 3mm (2.85mm) 1 kg for 3D Printing, Made in the USA, Natural