Weight coupling 30mm

I builed my self a little home gym. But professional metal weight plates a pretty expensive. So i designed those. I made a mold out of sheet metal and filled them with fiber reinforced concrete. They have an inner diameter of 30 mm to be compatabile with most systems. I used for myself a 30mm thick Stainlesssteel rod. My weights: 1,25 kg, 2,5 kg, 5 kg, 10 kg, 15 kg, 20 kg

I also designed some fixing collars for such a rod.

Link Men´s bar: https://www.prusaprinters.org/prints/151964-fixing-collar-mens-bar
Link short version: https://www.prusaprinters.org/prints/151965-fixing-collar-short-barbell

These coupling can be stretched for your needs.

I recommend to print them in PETG especially if the get used outdoors.