This Thing is a vertical stand for my 7 kg weights. The stand suits a weight set with 25 mm dia. shaft and 70 mm dia. locking ring, and has 6 mm dia. counterbored attachment holes. The base diameter is 120 mm due to the print bed size.

I've included the AutoDesk 123D design file so you can tweak the design as required.

The stand is surprisingly stable even without attachment!