Valentines Day + 3D Printing = Win!

Here’s my take on a Valentines day classic: The Sweethearts Candy Lithophane Lightbox!

This lightbox is modeled after the Sweethearts candy box design from the 90’s. I like the look of it for a light box, and the clear “heart window” in the middle of the box gave me an idea - What if we put a color lithophane of your “Sweetheart” here?!

So I took that “what if” and added some googling, some Fusion 360-ing, some trial and error with shnozzle sizes and light diffusers, and voila. I present to you the Sweethearts Candy Full Color Lithophane Lightbox! That’s kind of a long title isn’t it…

Anyhoo, I’m really happy with how it turned out! Also, using the LED board from the lithophane kit to make a lightbox worked really well in this instance. No wrangling LED strips, no cutting or soldering, plus I found out I could print the light diffuser directly onto the back of the lightbox to eliminate any hotspots. The downside is that this only really works well for rectangular light boxes, but it might be interesting to experiment with more than one LED board in future lightboxes… Hmmm….

OK, enough chit-chat, here’s how to print the thing:

Filament, PLA recommended:

Pink, Red and White for Lightbox

• I used Zyltech filament, it’s my go to for prototyping stuff. https://www.zyltech.com/pla-3d-printer-filament-1-75mm-1-kg-2-2-lbs/

Cyan, Magenta, Yellow, White for Lithophane

• Yes, you can use the same white filament for both, so 6 filament colors are needed to print the litho and the lightbox.
• You can get the filament and LED backlight as a kit from Bambu https://us.store.bambulab.com/products/pla-cmyk-lithophane?variant=41335266672776
• (Bambu was out of stock when I bought filament, so I make my own kit from Polymaker, they had a better magenta and cyan than Zyltech https://amzn.to/3UlPzcX *affiliate link*)

Parts, AKA stuff you might not already have:

.2 mm Nozzle (I’m assuming you have a 3D printer already 😉)

• No link, buy the one that fits your printer. X, P and A series all have differences in the hotends.

Bambu LED Backlight Board (If you didn’t buy it with the CMYK kit)

• https://us.store.bambulab.com/products/bambu-cmyk-backlight-board

USB C Cable and Wall Plug. They're not included with the backlight board.

• If you don't already have a USB C for another device, these cables work well for me https://amzn.to/3UlhlGj *affiliate link*

Models:

Sweethearts Lightbox with Heart Diffuser

Example CMYK Color Lithophane with Bambu’s Logo

• *This is loaded as a separate file because the print settings are different*

Negative Lithophane Heart

• Load this as a negative part in Bambu Stuido or whatever slicer you’re using

*From Bambu - CMYK Lithophane Frame

• Get the model here https://wiki.bambulab.com/knowledge-sharing/cmyk-color-lithophane/cmyk_frame_plate_1_v2.gcode.3mf

Recommended items:

AMS to handle the color changes.

Instructions:

Print Sweethearts lightbox with the .2mm nozzle using the pink, red and white filament. File for lightbox is setup to print the heart diffuser for the lithophane at the same time. I tried to keep it printable with a .4 mm nozzle, but I couldn’t get the text to print right and there were pinholes.

Create your color lithophane. Make it 65mm x 65mm square. I screencaptured my settings, check the attached pictures. Use the Negative Lithophane Heart file to cut out your heart when you slice it. (I was not able to find a better way to make a heart shaped full color lithophane.) Print with CMYK filament, the .2 mm nozzle will give you more detail, but if you haven’t installed it yet the .4mm will typically give good results, (I used a .4mm for the litho's in pictures). Here is the link to the Bambu color lithophane guide for additional information if you’d like to read it https://wiki.bambulab.com/en/knowledge-sharing/CMYK-color-lithophane-printing-instructions%20

Print the Bambu CMYK Lithophane frame. Light will bleed through the frame if you use white or other dark colors (It's true, I tested it), so use a darker color if you can. I used the Magenta from the CMYK pack. Remove the supports from the print when finished.

Do not print the light guide plate. This is integrated into the back of the lightbox already.

Slide the LED backlight board into the CMYK lithophane frame.

Put your color lithophane heart into the back of the Sweethearts lightbox. Snap the heart diffuser onto the back to keep it in place and diffuse the LED lights.

Gently snap your finished Sweethearts Lightbox Lithophane into the front of the CMYK lithophane frame.

Plug in your USB C cord and light it up!

You can see I picked my doggo as my sweetheart this year! I’ve included a Sweet-Heart lithophane print file for Bambu, I know corny, but whatever, Bambu deserves a valentine too and I thought it would be a good example of how the negative file works in the slicer so there ya go.

Now… you just have to decide if you’re going to keep it or give it to your “Sweetheart!”