Training Balisong with counterweight

It is a balisong for training.
For the weights you will need two (80-82mm) x 6mm brass rods, if not available you can also splice with multiple hex nuts and wrap tape around the perimeter to increase the outer diameter;
For the stop rod or shaft, you need four (>=12mm) x 4mm brass rods, or you can use two brass rods and two M4x16 screws like me, or all four M4 screws.
There is also a 65mm x 6mm brass rod reserved in the middle of the blade, but it does not affect the use if it is empty, or you can pour translucent resin into the middle like me for decoration