Curved Lithophane Box by DCRobotics

Last crawled date: 3 years, 3 months ago

Curved Lithophane Box.
I wanted to make some lithophane lightboxes for some gifts and I found lots of good ones here on Thingiverse. However, I wanted one that was curved, held just one lithophane, and had a completely enclosed light box, and I just wasn't finding what I wanted. So I jumped into Fusion 360 and came up with this design.
Print the LithoBody.stl and LithoLid.stl models first. Flip the LithoLid over before you print it. No supports are needed. I used a 0.6mm nozzle with 0.3mm layer height. It worked great and only took about 3 hours for the body, 1 for the lid. A 0.4mm nozzle with 0.2mm layers works good too, but it will take twice the time. Instructions for printing the lithophane are at the bottom.
Electronics Parts list:
12V LED light strips. https://amzn.com/B00HSF65MC
On/Off Switch: https://amzn.com/B07SPY9H7Y
LED Strip Connectors: https://amzn.com/B01DM7EXX2
DC Power Supply and Connector: https://amzn.com/B08BRPK9J9
Zip ties: use whatever you have on hand that fits.
Assembly:
Insert the DC Female Terminal Connector into the hole in the back of the model. There are two printed supports inside the model that will hold it into place. It will be a tight fit, but once you snap it down in there, its not going to move.
On the LED light strips, cut off two segments of 3 LED lights. Look for the cut marks on the strips. Insert the LED strips into the LED Light Connectors. The wire from the connector gets routed back through the slot at the bottom of the LED pillar on the model. Then zip tie the connector to the model, routing the zip tie through the slot on the side of the LED pillar. After the connector is secured, remove the backing from the adhesive of the LED light strip. The adhesive will help hold the LED strip to the model, but I've found that adding a couple drops of super glue to the adhesive makes for a stronger hold.
Insert the switch through the rectangular hole. On the switch, the "I" should be on top and the "O" should be on the bottom for proper On/Off orientation. The switch will snap into place, but you may need to use a little force to get it all the way on there.
Wiring time! Very simple switch circuit.
Take the 2 Red wires from the 2 LED connectors, twist them together and then insert them into the positive (+) terminal of the DC power connector. Make sure you have about 1/4 inch bare wire stripped away before you do this. Screw in the connector once the wires are inserted.
Next, we'll insert the Black wire into the Negative (-) terminal of the DC Power connector. Cut the Black wire to the right length (ensuring you have enough room to comfortably reach the Negative terminal) and then strip 1/4 inch of wire bare. Insert into the Negative terminal and then screw tightly.
Finally, you'll be connecting the two Black wires from the two LED connectors with the Red wire from the switch. Pull all three of these wires up out the top of the model. Cut them all to the same length, about an inch above the top of the model. Strip 1/2 inch from all three wires. Twist them and then solder them together. Add heat shrink to fully insulate the connection. (Note: There are multiple ways to connect these three wires. Do whatever works best for you, and is safe.).

Lithophane:
To generate the lithophane, use: https://3dp.rocks/lithophane/
This lithophane model is designed to hold images that have a 4:3 aspect ratio (100mm wide x 75mm high). Please crop your pictures to this ratio before using the website tool.
Key settings are...
Select "Outer Curve" model
Model settings:

Maximum size = 100
Thickness = 3
Border = 2mm
Thinnest Layer = 0.8mm (recommended if you're using a 0.4mm nozzle)
Vectors Per Pixel = I used 6, feel free to play around with this
Base/Stand Depth = 0
Curve = 60

Image settings:

Positive Image
Mirror Image = Off
Flip Image = Off

IMPORTANT: After you've generated your lithophane STL from the website, import it into your slicer. Pay attention to the model height. It may be slightly over 75mm (not sure why since a 4:3 ratio on a 100mm wide image would make the height 75mm, I typically see models around 75.5mm +/- 0.2mm). Adjust the "z" height of your model down to 74.9mm, but make sure your slicer is not scaling the "y" and "x" axis as well - you should only scale down the "z" axis.
Happy Printing!!!