I used to have an old dumbbell filled with sand, so thought it might be interesting to design a printer friendly dumbbell. The design is simple and is based on the classic barbell, allowing one to easily change weight plates to modify overall weight. I have provided 3 weight options, 200g, 300g, and 700g. The 200g and 300g is an approximation, depending on the print material and the liquid or material you chose to fill it with, once printed. It should take less than 100g to print each weight plate. I've also provided a sold plate, which would take 700 to 800g of material to print, if not interested in filling a weight yourself. This is a prototype, but will be developed more, as necessary. Upscale by 150 to 200% in slicer to increase weight.

I've test printed on a resin printer, but the parts have been designed to print flat, so it should be fine on an FDM as well. All parts should be printed at 100% infill for best strength and to increase overall weight to approach 5 (2.3kg) to 8 pounds (3.6kg). Be sure to glue the octagonal ends of the weight pegs into the ends of the grip. Other parts can be slid and screwed into place, without glue.

Print 1 wgtGrip, and 2 wgtPeg to create on weight bar. Print 2 wgtCap to use to secure printed weights.

Print 2 of each weights and 2 wgtPlug for each pair of hollows weights. The plugs are threaded to be screwed into each fillable weight plate.