DIY Wireless Follow Focus

Is it possible to build your own homemade, but powerful and feature-packed follow focus? Let's find out!

Youtube video: https://youtu.be/NZtYzvitv3U

The components that I have used include:

• Nema 17 (but don't use it, I'll explain later!)
• Driver for the motor
• two Arduino Nanos
• two NRF24L01 + PA + LNA
• Booster if you use 3.3V battery
• Potentiometer (make sure it's a LINEAR)
• Plate from SmallRig
• Rod and Clamp for mounting the motor
• two generic plastic electronic enclosures

Motor

Regarding the motor, I REALLY don't recommend using the Nema 17 because it's way heavier than it should be. Said that you should look into servo motors from eBay which have their own reduction mechanism. It will allow you to drive heavy lenses but the motor will be way smaller and lighter. If especially you have vintage or Cine lenses, these are designed to be driven easily.

With my setup, I can only use it with the Ronin-M. It does support it but becomes very heavy and hard to use.

Transceiver Module

The other thing you should know is not to use these cheap transmitter/receiver modules, but to invest a dollar or two more into the NRF24L01 + PA + LNA. Even the ordinary NRF24L01 are not good enough for a few meters. Believe me, I have tried them all :/

Potentiometer

Potentiometer choice is also very important. Make sure it's a linear potentiometer between 10K and 100K. I chose a 50K Ohms. You may notice a lot of variation in the voltage that the Arduino will be reading. This is bad. To negate this, you will need capacitors close to the Arduino's powerlines and the Transceiver module. Also, if this doesn't help, you will need to average a couple of readouts from analogue pins over some time. This will certainly help you in the long run.

Don't do it?

In conclusion, If you are looking to beat Tilta or DJI in the weight category, you've already lost. Of course, the money difference is big, but still, if you do this professionally I would recommend going with a factory solution - it will save you from the sweat in the long run. It took me quite a long time to make this. I have posted the code in the Youtube video's description!

If you have any questions regarding my solution, post them below. Make sure you watch the video and hope you have a great day!