Automatic Zen Garden with Magnetic Case

prusaprinters

DescriptionI recreated the  Zen Garden from JustBaselmans from scratch and made it more robust against sand entering the motor parts.Heres a short demo video of how it works:Since this is a motor powered zen garden, you will need a small motor to drive it (at least unless you don't want to turn the wiper with your fingers). All can be done with a small arduino and a stepper motor, powered by only 5V USB (so you can hook it to a powerbank for example). I will explain everything you need to build and set it up below:First, let me summarise what you will need to buy:Arduino Uno (or similar) Board (see note below)5V DC Stepper Motor 28BYJ-48 (see note below)ULN2003 Stepper Motor Driver Board (see note below)Some wiresM3 screws, nuts and washers5mm x 1mm magnets Quartz Sand in a color of your choice :)Optional: Potentiometer B10K to allow changing the speed of the wiperOptional: Wago Clamps to connect your wiresNOTE: All electronic parts mentioned above are already contained in this set. But feel free to get the parts somewhere else :)Putting everything together is not difficult. However, it requires some soldering and a basic understanding of how to read an electronic circuit.CircuitThe theory and the details of the circuit are very well explained here, connect everything exactly as shown below:Note: The potentiometer on the left is optional, you can also hardcode a fixed speed in your arduino code.CodingThe code to be used for the arduino is publicly available on my GitHub account:Just use the default Arduino IDE, copy the code (or clone to your hard drive), and upload it to your Arduino.Note: The pins used in my code match the circuit shown above. So, if you used different pins, you need to adapt the code! Otherwise you can just use it the way it is.PrintingThis is actually the easiest step :)Print the base, the cover, the wiper and, optionally, the knob with the prepared print settings. For the arduino cover I printed this model. The knob for the potentiometer was taken from Idee 3D, thanks!BuildingSuperglue the 5mm magnets in the mounts prepared in the cover and the base (make sure the orientation of both sides is correct before you glueNote: This step is not mandatory, but will allow the cover and the base to hold each other, of course you can also just place it without using the magnetsPlace your wired Arduino, Stepper Motor Driver, Potentiometer and Stepper Motor inside the base, put the USB cable through the hole (do not connect it to power yet!)Mount the stepper motor to the back of the cover (as in the picture), the holes should fit the stepper motor mounts perfectly. Use M3 screws and nuts to secure the stepper motor.Optional: Place the wired potentiometer in the provided hole, fix with the appropriate nut (if you use the set mentioned above its contained in there as well) Note: The potentiometer has a small nose that might block the potentiometer from fitting inside the hole perfectly, I used a 3mm drill to create a small hole.Optional: Place the knob on the potentiometer as soon as its tightenedMount the wiper on the stepper motor, note the orientationFor the first time, connect a 5V power source and ensure the wiper is turning (a little noise is normal and comes from the stepper motor itself)If everything turns as expected, check the potentiometer (if you connected it) and turn it to see if it changes the speed. Set it to a speed of your own preferenceFor the next step make sure you are in an environment which can handle some sand. Its likely you will spill some sand or some will flow over or your cat jumps on the table and makes a complete mess (a friend told me that). In other words, dont do it on grandmothers carpet, for gods sake :)Slowly start adding sand and wait for the wiper to distribute it. Make sure no sand is entering the hole in the middle!If sand gets in the hole, dont worry, just unplug the power, empty the cover and clean it with a small brush to ensure no sand remains, then repeat the previous step“Calibrate” your zen garden with the correct amount of sand, it should not flow over the edge of the wiperCongratulations, you built yourself an automatic Zen Garden :) 3D Model:All my models are created with Onshape and are publicly available for everyone: LinkFeel free to adapt it to your own needs. Also if you have a nice idea for a new wiper, let me know so I can add it to the model as an additional option :) If something does not work the way you expected or my explanation is unclear somewhere, let me know in the comments!                                        If you like my work, feel free to buy me a coffee :)