Weekly Update 1: Expanding scope bigtime

A project log for Paparazzi: An opensource camera robot

An automated arm for moving a camera in a repeatable fashion.

DavidDavid 05/18/2021 at 11:530 Comments

Got the pan/tilt module to move! The Joystick is connected to my desktop that is sending the values to a raspberrypi with UDP messages. The Pi has a servo hat from Adafruit. Add a comment if you'd like to see the code!

I spent a day trying to figure out how to smooth the servos (they sound super jittery which is definitely obnoxious. I added in some code so they would accelerate and decelerate to their new target and that definitely smoothed out the motion, which was pretty jerky when starting from rest. I also added a 100uF capacitor to the servo board, but that didn't seem to help. After watching a video recorded from the gopro, I realized it actually wasn't a big deal, I couldn't notice any shaking.

With that portion done, I really wanted to expand out the project after watching this video: 

The plan now is to stick a 3 axis servo gimbal out on a robot arm! I build up a prototype of the shoulder axis to test what kind of power I would need. 

I started out with a 23HS22-2804S nema 23 stepper motor with a 12:1 gear reduction. This setup was barely able to lift a 500 gram water bottle placed 18" from the pivot. I figure that's about half of the power I need since I want to move the gopro around at up to 36" and it will way around 400 grams. 

Just started the redesign: moved the shoulder motor off of the arm so it doesn't have to lift it's own weight, increased the gear reduction to 16:1 and I ordered a new motor with almost 3x the torque of the 23HS22. Should be able to lift a lot more!

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