Small linear actuators

Marco Reps

Oh, those are neat! I've been thinking about how initialize such a system with my no-feedback actuators. Wouldn't be necessary with those servos, BUT they are like 16 times more expesnive :)

Andy P.

You could also use the small stepper Motors of DVD / CD Drives like so <a href="https://www.thingiverse.com/thing:1765496" rel="nofollow noopener" target="_blank">https://www.thingiverse.com/thing:1765496</a>

Marco Reps

Hm, most of the pixels are turned off most of time, so I'd have put a bit of power into the system. But you are right, maybe the permanent magnets can be placed in such a way that they just barely catch the ferrofluid and only need a few mA to be disabled... Fantastic idea, thank you :)

Why not a hybrid approach? If you wind your own coils around a strong neodymium magnet it might get you a cheap effectivene system. You could adjust the spacing so the permanent magnets can *just* hold on to the ferrofluid. Then use the coil in one polarity to drop the fluid and the other polarity to hold/lift it.

Rick Mann

There are also the tiny servos for Blade helicopters: <a href="http://www.bladehelis.com/Products/Default.aspx?ProdID=SPMAS2000LBB" rel="nofollow noopener" target="_blank">http://www.bladehelis.com/Products/Default.aspx?ProdID=SPMAS2000LBB</a>

Dillon Nichols

Throw some magic magnets in there for good measure <a href="https://www.youtube.com/watch?v=IANBoybVApQ" rel="nofollow noopener" target="_blank">https://www.youtube.com/watch?v=IANBoybVApQ</a>

Marco Vujevic

1) If you want to keep acrylic in the game, you can maybe use one of those glass phone protector thingies and just stick it on the acrylic where you dont want the ferrofluid to stick. 2) I think I'd go with rotating cams (?) which have magnets on the side. that would be 3 for the top middle and bottom row and 8 for the vertical. the cams would have several "lines" of magnets in different paterns needed for the digits. Rotate them so that the correct set of magnets are closest to the front?

Morten Hanasand

Hey they're pretty cool, hope they work out for your purpose it got me thinking though about how I could use a miniature servo and a piezo sensor as a z-probe. it might seem like over-engineering, but z-probes are really tricky things to get working reliably.