DIY Motorized Turntable


My wife is an artist pursuing her master's degree, and as you all know, I spend most of my free time working on electronics and 3d printing projects, so I decided to find a way for us to get better videos and images of the projects that we create! I wanted to be able to easily capture shots of all sides of the projects that we work on, so I decided to try to make a motorized turntable. Now, of course I could just jump on Amazon and buy one, but what fun is that?! I could also get a non-motorized one, but I wanted to be able to maintain a steady speed without having to re-spin it all the time.

To make this thing, I picked up the following electronics:

For the brains, I used an Arduino Nano because I wanted the turntable to start up as fast as possible after plugging it in, and I didn't need any internet connectivity for this particular project. I also picked up a Nema 17 stepper motor from Amazon which, admittedly, is probably overkill for this project, but they are easy to use and pretty cheap to get. I also used a TMC2209 stepper motor driver to control the Nema 17 motor, which again, is probably overkill, but they are great drivers and they will give me incredibly smooth movement from the motor. Other that than, I picked up a flange coupling to allow me to connect the stepper motor to the turntable top, as well as various other electronic components to build out the circuit.

Circuit

The circuit for this project is fairly simple, though there are quite a few connections between the stepper motor driver and the Arduino Nano, which can make the circuit seem more complex than it is. Still, despite the simplicity, I opted to avoid soldering the entire circuit on perfboard, since many of my viewers have pointed out I stink at soldering... Instead, long story short, I tried making the circuit using my Snapmaker CNC router to isolate the copper tracks, and it didn't go well. If you want to learn more about what went wrong there, check out the video at the link above. After failing miserably to CNC the circuit board, I instead turned to JLCPCB to have my circuit designs printed.

Once I had designed the circuit to be printed on EasyEDA, I sent it over to JLCPCB, and 5 days later I had 5 working PCB's to finish out the rest of the project, plus this meant I had 4 extra PCB's for use in other projects to control a stepper motor. 

I also put together a button circuit that mounts on to the front of the turntable. All the buttons are connected to the same GND signal, so the PCB has three inputs (up, down, direction) for the output of each of the buttons. There are plenty of examples of wiring buttons up online so I won't spend too much time talking about that here, but they are coded as INPUT_PULLUPS, so only two pins (GND, Signal) are needed per button. I find that this helps tremendously when trying to preserve Arduino pins where possible. 

Assembly

The last thing to do once I had the circuit boards, was to design the parts to be printed and put it all together! The assembly is fairly simple, the PCB takes an input from a 12V power adapter, as well as the three buttons, and it outputs the 4 motor signals (red, green, yellow, blue) in that order. For all the inputs and outputs, I used screw terminals so I could easily assemble and disassemble the connections. I also mounted female header pins in place of directly mounting the Arduino and the TMC22209, so that if something goes wrong with either component, I could easily swap it out. With the circuit all connected, I mounted the buttons to the front of the base, and the PCB to the bottom of the base.

I then mounted the flange coupling to the turntable top, attached the motor mount to the Nema 17, and tightened the flange coupling onto the axis of the motor. Lastly, and this was the hardest part, I mounted the motor to the base by flipping the entire turntable over, and screwing it in from the bottom. This probably wasn't the best way to design this, but I wanted the gap between the top and bottom to be as small as possible, so I wouldn't have been able to tighten the flange coupling if I had mounted the motor to the base from the inside.

Usage

With everything put together, I could now get on with actually using this thing! The controls are very simple, the left button slows the top down, the right button speeds it up, and the middle switches the direction that it's spinning without affecting the speed. 

That's it for this project thought, I hope you enjoyed it! Make sure to check out the video I made on it if you want a more detailed idea of how I put it all together, and make sure to subscribe!

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