This is a design for a weight that weighs approx 15 lbs when filled with cement. It prints in 4 parts that fit together (requires glue for firm hold). No support material is required, and fits on a standard size printer.
You will want to put holes into the part to be able to fill it with cement. Feel free to experiment. The weight could be scaled as well for larger bars and to get bigger weights.
Fee free to modify the cad to suit and post your changes so we can all enjoy.
I started making a narrower one but it is unfinished as of yet. CAD is here anyway.
The author marked this model as their own original creation.