How to make an easy yet strong robot arm

I'm designing and 3d printing a robotic arm to hold a camera and make graceful camera movements. In this video I 3d print the shoulder and elbow joints and make initial trials with a camera!

These are the supplies i used: NEMA 17 stepper: https://amzn.to/3gtK3Qd Arduino Mega: https://amzn.to/3nx3Oui 5mm steel rod: https://amzn.to/3HMBGeV Thin wall bearings: https://amzn.to/3gtYLqG and: https://amzn.to/3H7JPZY 1.75mm PLA+ filament: https://amzn.to/3HvzVT5 The PTFE grease came from eBay - search for "50g silicone PTFE grease" ... https://www.youtube.com/watch?v=u4ynKC0TWL8