I’d used a pair of shears to cut through the tube, with the result that the end of the tube got squashed flat. There are two ways to resolve this. Firstly, Dave slips a cocktail stick into the tube and then cuts through it with a slitting disc in a mini-drill. However, the tube that we’re using on our signal is too small for a cocktail stick. Therefore, Dave uses shears to cut the tube to length and then re-forms the opening with a pair of pliers. He then uses drill bits and broaches to bore out the internal shape of the tube.