A remix of the Rotary Tumbler by Colleone. These are the changes:
- A 3D printed base instead of using the wood plate.
- Longer and higher box for the motor and electronics.
- An Arduino based digital motor controller that supports settings the motor speed and the duration.
- The 3D parts are cut to fit smaller printer print-volume.
Follow the original part list for building the tumbler.
For the digital controller:
12V DC 2A Power supply.
Resistors: 2X470 ohm, 1K ohm, 330 ohm
100 uf capacitor
Arduino pro micro (You can use any 5V Arduino)
7805 voltage regulator
LM317T voltage regulator
1.5 A Fuse and Fuse House
4 Digit 7-segment display
A simple relay
A prototype board
The digital potentiometer principle:
The Arduino generates a PWM signal that feeds the RC circuit. The PWM frequency dictates the input voltage to the 741 Op-Amp. The Op-Amp regulates the output voltage of the LM317 that feeds the motor. It is based on this circuit: https://forum.allaboutcircuits.com/threads/lm-317-with-digital-potentiometer.117423/ but with an RC and PWM instead of the RV1.
Follow the Fritzing diagram when you build and test the circuit. Pay attention to the inputs and outputs connector of the LM317 and the 7805, they might be different than the Fritzing diagram.
You may want to change the speed factor (the PWM signal) in the Arduino code if you have a different motor than mine.
I use ABS. To make my Printrbot printing ABS, I wrap the printer with a large plastic bag. This keeps the environment temperature stable and enables clean ABS printing with no wrapping. I set the heated bed to 130 degrees and the hot-end to 245 degrees. I use Buildtak.