Maker Johan WV has launched an upgraded design for his Passive Pixel Pole, a flip-dot show which used a floating magnet to offer at-a-glance water degree indication on a borehole pump-filled tank — till its elements corroded, one thing the brand new model goals to unravel.
Johan’s authentic Passive Pixel Pole was put collectively three years in the past utilizing an inside magnet floating in a food-safe bottle to flip painted washers on the skin — serving because the aforementioned “pixels” of an at-a-glance degree meter. The magnet additionally triggered a reed change on the backside of the tank, triggering a relay to activate a borehole pump when the water degree will get too low.
Whereas practical at first, the design proved problematical. “The relentless march of time introduced with it not solely knowledge, but additionally corrosion,” Johan admits. “It seems that, regardless of efforts to seal the tube at each ends, moisture discovered a option to infiltrate the mechanism, sometimes manifesting as condensation on the within of the tube, however, extra perniciously, leading to rust of the metal washers, regardless of the presence of paint on each faces. Moreover, some pixels have been apt to get caught.”
An accident whereas changing the tank’s inlet ball valve which broken the pipe known as time on the unique design, and Johan set about constructing one thing which might higher stand the check of time. The welded washers have been first to go, changed by 3D-printed plastic “pixels” — printed first in black, then in inexperienced to offer an apparent signal that the pixel is “on.”
A slot in train plastic flapper homes a 3mm rare-earth magnet, wihch in flip touches a stitching pin serving as an axle. Every plastic pixel is round half the scale of the unique washer model, doubling the decision of the show — and printed black frames present a visible distinction whereas sliding neatly into the brand new glass tube, initially a T12 fluorescent lamp.
The revised Passive Pixel Pole makes use of as little steel as attainable, and boasts twice the decision of the unique. (📷: Johan WV)
“Spacers on the prime and backside of the assembled system provide hole area into which one can stuff some desiccant baggage,” Johan provides, in his effort to stop the corrosion points which did for the unique design.
“Extra 3D printing: there are finish caps on the tube, lined with adhesive aluminum tape burnished easily onto the glass, after which lined with stretchy self-fusing silicone tape for good measure. After a few months out within the open, I’m quietly optimistic that we might have crushed the moisture monster, and all forty-odd pixels are additionally nonetheless behaving impeccably.”
Full construct particulars can be found in Johan’s Hackaday.io web page, whereas the 3D-printable “pixels” have been printed to Thingiverse below the reciprocal Inventive Commons Attribution-ShareAlike license.