Revisiting a classic, we create a digital version of the Etch-A-Sketch. Learn how to convert your cellphone into a digital plotting toy using 3D printing technology.
In this age of technology, entertainment is an easy thing to come by. Films, series, and games are as limitless as the platforms they’re displayed on. Yet, we still have to respect — and once in a while enjoy — the classics.
In this Weekend Project, we’ll be making a digital version of the classic Etch-A-Sketch using some 3D printed parts and a smartphone. Towards that end, we’ll be following the design from Ali Aslam (YouTube username Potent Printables).
The Classic Version
The original Etch-A-Sketch works thanks to grey aluminum powder under the glass screen. This non-toxic substance is mixed with plastic beads to help it evenly redistribute across the glass whenever you shake the toy to resett the drawing area.
Drawing is aided by two knobs, which are connected to a wire and pulley system. The knobs initiate X-Y movements, and whenever you turn them, a brass stylus etches the aluminum powder from the screen in very thin lines.
The Digital Version
The Cell Phone Etch-A-Sketch makes use of a conductive stylus mounted atop a 3D printed apparatus holding a smartphone executing a drawing app. This digital Etch-A-Sketch is interesting in a number of ways:
Naturally, there are some drawbacks:
Let’s get started!
The printable parts include the knob retainer, y-axis rack, y-axis knob, x-axis carriage, x-axis knob, and the base plate. Ali provides all of the STL files and print settings on Thingiverse.
Beyond the 3D printed parts, you’re going to need the following:
Helpful, but not necessary:
Ali found differences in the sensitivity of Android and Apple devices during the testing of different phone types. In particular, this relates to how each phone senses and responds to the stylus.
Ali provides a detailed PDF of the assembly process on Thingiverse, but we’ll still summarize the important parts.
The x-axis component slides into the base plate and must interlock its “teeth” into those of the X-axis knob.
Ensure that both the x- and y-axes slide smoothly against each other, sanding where necessary. Your knobs must turn freely and smoothly once installed in the holes of the base plate.
Use the drill bit to clean the opening in the y-axis where the stylus will fit. The KwikWeld is used to join the knob retainers to the knobs. Even after bonding, your knobs should turn smoothly.
Epoxy your cut silicone sheet to the bottom of the base plate, then cut a phone mat from the silicone sheet and bond it to the x-axis carriage using epoxy.
It’s now time to assemble the y-axis sub-assembly. Use epoxy to glue the jumper wire on top of the stylus and on the groove of the y-axis. The y-axis sub-assembly will then go into the mating dovetail groove on the base plate. The y-axis rack should move smoothly through the dovetail groove.
The free drawing app that can be used on Android phones is called “Simple Draw”.
The assembly is similar to that of Android phones, apart from adding a wrist band.
On the y-axis sub-assembly, epoxy one end of the longest jumper wire on top of the stylus and the other end on the groove of the Y-axis. The wire should extend past the end of the Y-axis rack. You will then insert the Y-axis sub-assembly into the mating dovetail groove on the base plate.
Wear a wrist strap band and use the attached alligator clip to clamp onto the needle-like metal part of the jumper wire that will be sticking out of the Y-axis rack. Ensure the metal plate on the band makes contact with your bare skin.
The free drawing app that can be used on iPhones is called “Simple Draw PW”.
During usage, place your phone on the mat and make sure the app is running. Move the stylus over the phone and turn the knobs to control the movement of the stylus on your phone’s screen. The x-axis knob causes the stylus to move in a horizontal direction while the y-axis knob causes the stylus to move in a vertical direction, or at 90° to the horizontal direction.
For iPhone users: After you’ve placed the iPhone on the mat and the stylus is over it, wear the wrist strap band and ensure the alligator clip is clamped on the metal part of the jumper wire sticking out of the y-axis rack. The metal on the wrist strap band must make contact with your bare skin to trick the iPhone into “thinking” that your finger is touching it.
License: The text of "Weekend Project: Cell Phone Etch-A-Sketch" by All3DP is licensed under a Creative Commons Attribution 4.0 International License.
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