A 2”1/8 hole is drilled in the centre of the front of the seats to accept the control stick and torque tube. This has to be dead centre.
After bonding together the torque tube to the control fork, this is fixed with Redux and rivets, a plastic shim is used to get a nice smooth operation after the Redux has set, it is trial fit to the CM then the fixing hols are drilled after a careful set-up of the tube.