The Martlet 1 rocket has fins that are made in two parts: the outside edge is machined aluminium to give a high temperature, sharp leading edge, which it will need at Mach 2. The inside of the fin is made of carbon fibre honeycomb, to be strong and light.
The fin sections were first cut using a simple aluminium jig and a diamond coated jigsaw blade.
The edges of the honeycomb were then rebated by about 10mm, so that the flange on the aluminium edge can be bonded in.