Nylon is missing in GateMaterial.db, add it

/gate/FrontPad/geometry/setXLength 1.9 mm /gate/FrontPad/geometry/setYLength 40. mm /gate/FrontPad/geometry/setZLength 40 mm

/gate/FrontPad/repeaters/insert cubicArray /gate/FrontPad/cubicArray/setRepeatNumberZ 3

/gate/FrontPad/placement/setTranslation 54.85 0. 0. mm
