3D Printed Lithophane in Foam Jack O' Lantern
Introduction: 3D Printed Lithophane in Foam Jack O' Lantern
I upped my personalized foam pumpkins last year by integrating 3D printed lithophanes, but ran out of foam pumpkins. I've improved the process this year by eliminated the sharp edges/corners, and bought more foam pumpkins.
Supplies
* Craft foam pumpkin. Hollow, not solid. I've been using the Ashley brand from Michaels. They often have 25 to 30% off coupons, and go on sale for 60% off before October.
* LED tea light, or the LED linked below.
* https://www.amazon.com/gp/product/B07W726LD5
* 3D printer
* PLA Filament. There is an eSun white that is typically recommended for lithophanes, but for this style I suggest an office white that matches better with the shade of the carved foam pumpkin.
* Hot glue gun
* Orange hot glue (or optionally clear)
* Color 2D printer (color laser is what I used)
* Double sided clear tape
* Exacto Knife
* Pumpkin carving tools (specifically a scraper)
* Carbon Paper
* Pencil
* Software:
* Slicer (Cura for instance)
* ItsLitho.com (for create the lithophanes. They have an option for color lithophanes).
* TinkerCAD.com
* Blender.org (free 3D program)
* Lunapic.com
Step 1: Remove the Background From the Image (optional)
This step can be skipped, but I highly recommend it, it creates a nicer result. Open Lunapic.com in your web browser. Upload the image you want to use. Use the remove background option, and click a spot of the background. Doesn't get over zealous with the percentage, or you may remove some of the foreground. Bit by by, detect and remove sections of the brackground. 644
There is also an eraser tool, so you can do some manually. Zoom in to the image where necessary, and try to smooth out the foreground image as well as you can.
Note: While the lithophane application will allow you to tweak the brightness and contrast settings, it will affect the background; so you may want to return to LunaPic and make those adjustments there before saving.
Export/save the image as a PNG (to maintain the transparent background). Rename the file (now in your download folder) to something more helpful, like the family's name.
Step 2: Convert the Image to a Lithophane
Open ItsLitho.com in your web browser.
Select create.
On the image tab, upload the image.
If you removed the background (make it transparent), set the option for Bg intensity - Set to zero (so background is solid black, no/less light coming through).
You could optionally adjust the brightness and contrast here, but if you made the background transparent those settings will affect it as well.
On the "EDIT" tab, change the shape to "Arc".
Change the "angle" to either 30 (for small width images) or 45 (for larger width images). This will follow the curves of the foam pumpkin better.
Set "Frame" to "none".
Set "Height" to "100mm".
The application will fill in the width for you.
Leave "Min Thick" as "0.8mm".
Change "Max Thick" from "3.2mm to "2.00mm".
Save/Generate the Lithophane. Here you will see an option for the color lithophane, save that as well. You'll have an STL and a PNG file saved in your download folder.
Step 3: Create an Arch Template
Using TinkerCAD create an oval shape. Create a rectangle as well.
Position the oval into the center of the rectangle, and make it hollow.
Combine the two objects.
Save it as an STL. Or just download the one I provided.
Step 4: Modify the Lithophane Into an Arch
Note: This took me longer to figure out than I care to admit. TinkerCAD has a maxium file size limit. MeshMixer failed to produce the result I wanted.
Open the 3D modeling tool Blender. Import the lithophane STL. Also import the Arch STL.
Rotate the Arch so it is oriented the same as the lithophane.
Now adjust the height, width, and depth of the Arch to cover the corners and edges of the lithophane.
You'll want your image positied/visible in the Arch/oval; the rest of the shape is goind to be removed. 110