The image of wedge and feathers is taken from the internet. The dimensions of the original tool are different.The tool is for a hole with diameter 22mm.
Step 1: Wedge
For the wedge I used a piece of steel, 1,5 cm thick. Then I cut a piece 20 cm in length
Step 2: Dimensions of the Wedge
The biggest part of the wedge is 24mm and the smallest is 7mm. Mark the wedge with a pencil and cut it.
Step 3: Cutting the Wedge
Cut the wedge with an angle grinder
Step 4: Final Piece of Wedge
Picture of the final piece of wedge. The final piece of the wedge should be like this
Step 5: Feathers
For the feathers I used construction steel bars 19 cm in length. Cut 2 of these.
Step 6: Dimensions of the Feathers
The diameter of the two feathers should be 22mm. To achieve this, it's better to cut the steel bars with an angle.
Step 7: The Final Piece
The final piece should be like this. Cut other 2 or 3 to break the rock easily.