¶ Holes
¶ 2020 x 200mm
Drill two 6mm holes. They should be 28.28mm from the center of the 200mm extrusion.
¶ 2020 x 300mm Counterweight bar
You might use a different length of extrusion. The mounting holes need to be according to this sheet regardless of length:
Depending if you use M4 or M5x40 screws for this, drill 4 or 5mm holes.
¶ Taps
The thread size depends on whether your extrusions have a 5 or 6mm center hole. Tap with either an M5 or M6 tap.
¶ 4040 x 75mm
¶ 2020 x 50mm
The short 2020 extrusion should be tapped on one side.