Rock tumbler with timer

Rock tumbler with timer

I was thinking of printing JT3D's Affordable rock tumbler but wanted a little more control so I decided to build one based on an Arduino.

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.

Assembly

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.

There's a replacement stl included for the right side of the frame if you decide to go that way.

Barrel insert

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.

Arduino wiring

I used an arduino uno and a perma-proto board to mount the electronics on.
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.

I couldn't find the correct representations for the components so you'll have to check each part for how to connect them.

Hardware

I've put what I used in parenthesis

• Arduino + wires (Arduino Uno rev. 3)
• 64x48 oled (OLED Shield for WeMos D1 mini)
• Stepper Motor driver (Adafruit TB6612)
• Perma-proto board (Adafruit Perma-Proto Half-sized, 82mm x 55mm)
• Voltage regulator (Luxorparts, 4.5-28 V to 0.8-20 V. Based on MP1584)
• Power Adapter (9V, 2A)
• Button
• Potentiometer
• Power switch
• 8mm Threaded rods
• 8mm Nuts, lock nuts, lock washers
• Bearings, 22mm x 7mm M8
• O-rings for the wheels Video