I’ve been really intrigued by various Etch-A-Sketch automation projects out there (here’s a few.) I’m excited by the prospect of a large, diy, low energy display. I’d love to use one to make a web-synced wall calendar. I can see two major hurdles in the The Etch-A-Sketch route though: You can’t lift the pen, and you need to shake it (or redistribute the powder somehow,) to erase the drawing.
I went around and around in my head, trying to figure out how to overcome these issues, when my girlfriend says, “Why not use a Magna Doodle?” Why not indeed! The erasing process is just a swipe of a magnet, and there’s no aluminum dust to contend with. Much easier. (I should mention here that while I have always known this toy as “Magna Doodle,” that’s a discontinued name. Fisher Price bought it and renamed it “Doodle Pro.”)
There’s a wrinkle though. Unlike the Etch-A-Sketch, the Doodle Pro needs the pen to be on the viewer’s side of the screen. That would probably be ok, but ideally I’d like all the display hardware to be hidden from view. What to do, what to to?
Well, I got some cheap Doodle Pros today, and upon taking one apart, it looks like that may not be an issue. It turns out that when you draw something on one side, you get a decent negative on the other! So I’m going to try, at least at first, to create a display with the pen hidden from view. The user will see a black (gray, I guess) background with white lines. The lines are a little fatter than I’d like, but there may be some improvements that can be made to the pen that will fix that.
Tags: Magna_Doodle
I can picture a needle or small metal stylus used as the core of an electromagnet. Turning the magnet on and off would allow the start and stop of lines. Varying the power of the magnet might lead to some interesting effects. Neat concept!
That’s probably the way I’m going to need to go with this one. I need a magnetic field that’s stong and focused on as small an area as possible, while not disturbing the surrounding areas.
the next order of business though, is getting a 2-axis rig built. regardless of what I do for a pen, I’m going to need to move it around.
Hello, I was just wondering if the front of the doodle board is blue, since I’ve always thought that the magnetic lattice is white. Is it possible that the lattice can be transparent? Anyway, cool idea!
Thanks!
sorry it’s not clear from the post, but the liquid is still white. they just stuck a blue film in front of it.
as far as transpart liquid? I don’t think that would work. since the metal shavings stay in the cells (just getting pulled towards or away from the viewing surface,) you need something opaque to hide them.
Hmmm because I’m on a project involving placing an LED board behind the lattice, but I don’t know if the lights would be able to shine through since the liquid is white :\