Rock tumbler with timer

prusaprinters

<h3>Rock tumbler with timer</h3><p>I was thinking of printing JT3D's <a href="https://www.thingiverse.com/thing:935252">Affordable rock tumbler</a> but wanted a little more control so I decided to build one based on an Arduino.</p><p>The main thing is the stepper motor and using it's rpm and steps/revolution to get an approximation for how long it will run.</p><h3>Assembly</h3><p>You should be able to put it together by just looking at the pictures. One thing I decided to do is put bearings in the right side wheels and let them move freely. The drive side is fixed and the bearings sit in the frame.</p><p>There's a replacement stl included for the right side of the frame if you decide to go that way.</p><h3>Barrel insert</h3><p>The insert for the barrel is 153mm wide. I bought some anti-slip mat that I hot glued to the inside and then just put some glue on the edges and forced it in. I use a bunch of nails and rivets as my polishing media.</p><h3>Arduino wiring</h3><p>I used an arduino uno and a perma-proto board to mount the electronics on.<br>My power adapter is 9V 2A so there's a voltage regulator between the power cord and motor to get it down to 4.83V.</p><p>I couldn't find the correct representations for the components so you'll have to check each part for how to connect them.</p><h3>Hardware</h3><p>I've put what I used in parenthesis</p><ul><li>Arduino + wires (Arduino Uno rev. 3)</li><li>64x48 oled (OLED Shield for WeMos D1 mini)</li><li>Stepper Motor driver (Adafruit TB6612)</li><li>Perma-proto board (Adafruit Perma-Proto Half-sized, 82mm x 55mm)</li><li>Voltage regulator (Luxorparts, 4.5-28 V to 0.8-20 V. Based on MP1584)</li><li>Power Adapter (9V, 2A)</li><li>Button</li><li>Potentiometer</li><li>Power switch</li><li>8mm Threaded rods</li><li>8mm Nuts, lock nuts, lock washers</li><li>Bearings, 22mm x 7mm M8</li><li>O-rings for the wheels Video</li></ul><figure class="media"><oembed url="https://www.youtube.com/watch?v=vNP2_rVvvXg"></oembed></figure>