Halloween is getting closer, but black cats are lucky any time of year! Stick them on your windows, tuck them inside lamps, or hide them around the house. Choose from solid, Voronoi, and spiral designs. Let light shine through the patterned designs, or use glow-in-the-dark filament to add some spooky bling.
These cats are fast and fun to print, but the main point of this Thing is to provide a tutorial that illustrates how quickly and easily you can turn an image from the web into a cool 3D-printable shape. Read on to find out how!
The cat models are 1mm thick, and the patterned ones have pattern starting at 0.5mm high. With .3mm settings, my Replicator translated this into 2 layers of base and 1 layer of pattern. If you're swapping filament to change color for the pattern then you'll have to be quick to pause the printer right after the second layer.
Overview of the design process
You can create 3D-printable files for these cats or any other images in just a few minutes using Google Image Search, an online SVG file converter like Online-Convert.com, and Tinkercad.
I'll walk through everything step-by-step in great detail below, but don't let my verbosity scare you away. The process is simple and quick: Find an image, convert it to SVG format, upload the image to Tinkercad for scaling and decoration, and then download for 3D printing. It only took about 10 minutes to create the first cat design.
Step 1: Find a good image
The first step is to find the image that you would like to use in your design. You can draw, create, or photograph any image you like, but of course the easiest thing to do is to Google it. Go to Google Image Search and type what you are looking for into the search bar. I typed "black cat" and then clicked on the "Clipart" button at the top of the results. The very first image was perfect; thank you, clipartpanda.com!
Clip art, line drawings, black-and-white or one-color images, and images with transparent backgrounds are often good candidates for turning into 3D models. You can use the "Search Tools" button in Google Image Search to restrict your search to different colors or types of images.
Here are some things to keep in mind when selecting an image:
- If your image has disconnected pieces then it will 3D print with disconnected pieces, unless you give it some kind of backing or connectors after uploading the image to Tinkercad.
- Multicolor images may not work the way you expect, since every color in the image will be interpreted as either "on" or "off" when you import the image into Tinkercad. For example, the cats with green eyes in the image search results above might end up looking like they have no eyes at all after importing to TInkercad.
- Thin lines in your image will be thin lines in your 3D print, and this can cause problems if the details are too fine for your printer. For example, consider the curly-tailed cat at the end of the third row of search results in the image above. If the tail and whiskers are wide enough to print as a nice solid line of filament, then the design could turn out beautifully. Or not, if the lines are too thin. (Pro tip: If you have a 0.4mm nozzle on your 3D printer, and you probably do, then you should aim for line widths that are at least 0.4mm.)
Step 2: Convert the image to SVG format
In order to import your image into Tinkercad, it must be in SVG format. There are software programs that will convert images to SVG (for example Inkscape or Illustrator), and also lots of online tools that will let you convert file formats for free. I chose to use Online-Convert.com.
The upside to a free online converter like Online-Convert.com is that it is fast and free. The downside is that the site is full of large green arrow buttons that are not part of the download process, but rather are part of embedded advertisements on the site. Read carefully, upload your image file, and then find the small "Convert File" button to obtain your converted SVG file for download.
(Truth be told, the cat image I happened to use was also available in SVG format, so I didn't need to do the process above. However, restricting your Google Image Search to SVG can be very limiting for your search results, so it's good to know how to convert to SVG rather than search only for SVG files.)
Step 3: Import the image into Tinkercad
Uploading your SVG file to Tinkercad is easy. First, get a free account at www.tinkercad.com if you don't have one already; then open a new Design. In the right column menu, open the "Import" tab and then use "Choose File" to browse for the SVG file on your computer. Once you've located and selected the desired file, press the "Import" button. The upload process can take a minute or two if your design was particularly complicated.
After the upload process is complete you should see a 3D object with 10mm thickness, whose outline is determined by your image. At this point you'll know immediately if your image was a good choice; it will either look good or it won't. Mine looked pretty good but it was giant!
To resize the design to something more reasonable, zoom out and grab the corner selection dot, then hold Shift while dragging the model to a smaller size. Note that this will also make the model thinner, so let's fix that in the next step...
Step 4: Scale and repair the extruded model in Tinkercad
You can click on your model to see how thick it is, and then scale it using the corner selectors, but there is an easier and more accurate way. Open the "Helpers" tab in the right menu column, and drag the "Ruler" tool to the blue grid Workplane. Set the Ruler down anywhere you like on the Workplane (not on your model). Now when you click on the model, you'll be able to see all of its dimensions, and even change those dimensions by clicking in the boxes and typing the exact values you want to assign. I set my cat models to be 1mm thick.
If your image uploaded with weird bits or any elements that you'd rather not use in your final model, then you can erase those parts of your image model. Create box-shaped "Holes" over the parts of the design that you want to erase, and then "Group" those holes with the design to make the undesired parts disappear. (For a primer on basic Tinkercad tools and methods, see the Tinkercad page on Jumpstart.)
Step 5: Add decorations or use the image model in a larger design
Now that you have a 3D model based on your selected image, you can use that image as a design element in a larger model. For example, at this point we could create a keychain design in Tinkercad and use the cat shape as an image or cutout in the keychain. Alternately, you can just decorate the image model and 3D print it as-is, which is what I decided to do.
To make the stained glass (spiderweb?) cut-out pattern, I used the "Vornoi" tool in the "Tinkercad" submenu of the "Shape Generator" tab in the right column menu. After settling on a nice Voronoi pattern, I made it 1mm high, turned it into a Hole, and then Grouped it with a Box of the same dimensions. This made a cut-out pattern that I raised 0.5mm from the Workplane, set as a Hole, and then Grouped with my cat model. The spiral cut-out pattern was made a similar way, but with another image that I found in a Google Image Search for spiral hypnosis.
If you want to play around with the cat models and pick them apart to see how they were made, you can edit my design in Tinkercad.
Step 6: Download as an STL file
When you're ready to download your model, use the "Design" menu in the upper left and select "Download for 3D Printing", then "STL". You'll have to close the Download window once your design has downloaded. Now 3D print and enjoy!