Fail Of The Week: Arduino Sand Matrix Printer

NYC beaches are where tropical beaches addicted to meth go to die. So says [Vije Miller] in his write-up for his Arduino sand matrix printer. It’s a clever idea, five servo-operated cardboard plungers that indent a pattern of dots in the sand as the device is pulled forward, resulting in something not unlike a dot matrix printer that can write messages in the sand.

He’s submitted it to us as a Fail Of The Week, because it doesn’t do a very good job of writing in the sand, and it’s burned out a servo. But we feel this isn’t entirely fair, because whether or not it has delivered the goods it’s still an excellent build. Cardboard isn’t a material we see much of here at Hackaday, but in this case he’s mastered it in a complex mechanism that while it may have proved a little too flexible for the job in hand is nevertheless a rather impressive piece of work.

You can see a brief video below the break showing it in action. He tells us his motivation has waned on this project, and expresses the hope that others will take up the baton and produce a more viable machine.

This may be our first sand matrix printer, but it’s not our first sand 3D printer.

2013-09-05-Hackaday-Fail-tips-tileFail of the Week is a Hackaday column which celebrates failure as a learning tool. Help keep the fun rolling by writing about your own failures and sending us a link to the story — or sending in links to fail write ups you find in your Internet travels.

29 thoughts on “Fail Of The Week: Arduino Sand Matrix Printer

  1. Very clever design. You could replace the cardboard linkages with bits of aluminium bar. It’s easy to cut and drill and it’ll be stiff enough. No cnc required.

    I like the design of the pins. Excellent cardboard engineering!

    You could also add a rake to the front to texture the sand so that the dots stand out a bit more.

    1. Had I access to a CNC, definitely would have constructed this entirely from MDF and then been able to create a better (and working) driving wheel that printed the letter while adhering to the surface far better. I had first envisioned a cylinder that rolled along and imprinted letters as the entire unit rolled. A third or fourth sketch imagined a more matrix printer structured – a gear, pulley, cross bar set up – but like most things, I did not have easy access to such components.

      My advice shd any one attempt —
      1. Depth matters, over compensate
      2. Sand, not too soft and not too wet. Too wet (dense) and the printer has to be heavier (or grabby) to resist counter pressure. Too soft and the displacement of sand ruins the print.
      3. Incline of the beach has to be compensated for. If you have a nice flat beach – huzzah!
      4. Screw it and just go to the beach any ways — I suggest Siesta Key in Sarasota, Florida. Sand like sugar and water bath tub warm and waist deep 50 yards out. God, I hate NY *weeps*

      1. I think you got the idea right here, but you just needed more arms in a tighter space. It’s difficult to make out the letters only because the resolution is spaced so far out. I think this deserves another go around. This time, instead of stamping the sand, get a lot more servos together and fashion a servo horn with a 90 degree elbow. It just needs to gouge the sand like a stick. You could even arrange the servos in a semicircle (like an old typewriter!) so each arm lands next to the others. I believe in you, give it another go.

  2. It’s an experimental prototype to see if the concept works. It’s the crawl stage of “crawl, walk, run” development; learn everything you can from one stage before moving on to the next stage..

    1. He needs to ditch the cardboard and just hot glue an L-shaped stick to a servo horn. As the servo rotates back, the stick will gouge the sand. With less complication, he could stick more servos next to each other or even arrange them in a semicircle so the sticks all land within a half inch or so of each other. Kind of like a typewriter.

      1. Had tested a simple arm-to-servo mechanism and immediately found that the F per sq inch was greater with a levering system — and with the goal of depth via pressure, this was paramount. The main issue was the opposing energy lifting the frame, effectively terminating the F in to the sand. F it.

        I agree with the more servos you noted in another comment but I have limited resources and time. I often settle for proof of concept than actuals.

    2. The mechanism may consist of a rake where each tine is hinged to move sideways, and a DC motor wiggles the tine sideways via a cam. This will draw narrow parallel lines with wide marks whenever a motor is activated. like a polygraph.

  3. some counter weights would have gone a long way, and maybe a better “stamp”. it also looks time-based rather than position-based to do the “printing”, an optical sensor from a mouse wouldn’t be too hard to hack in either.

  4. Does the Arduino IDE not allow for creating an array of functions? If so that would be a perfect use instead of the giant IF ELSE block. Alternatively, a switch/case group is much more compact.

    Apparently one can create an array of functions so that the entire if/then or switch/case can be eliminated with just a call to the array index as shown

    1. I reviewed several methods to possibly employing an array but in the end it still required identifying each alphanumeric column so for this first version I had chose to use a more certain process to assure the events and to aide in if errors occurred. Oh yeah, and I hate coding more than you could ever imagine. Right hemisphered here, tend to prefer things spatial and not linguistic. Hate, coding.

    1. The sled is leveling out the sand, so just drop it in at the rear of the sled. Also, the sled will probably block most of the light from the sun. Optical/Laser mice work by using the mouse as a light block and creating a small cavity inside at the center. The only thing he really needs to overcome is smoothing out the sand which he appears to already be doing.

      1. To note — worse, sand, ever. Your living space (any one’s) is bigger than this area of beach (a rarity, which seems odd for an island) utilized in Astoria, New York for this project and the sand is composed mostly of what I assume from sight is the run off of a used baby diaper slash syringe slash tire factory – so I was limited on density and texture and a less than 4 hour tide window to find “dried” sand. I know people would have a far easier time any where else.

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