Parts A, C, and E are cut of 1/4"-thick wood, while parts B and D are 3/4" thick. Cut all 5 pieces to 3-1/2"×3-1/2".
Holes have to be drilled in all pieces except part E.
For part A, cut a large hole in the center, anywhere from 1-7/8" to 2" in diameter, depending on the size of the domed half of your capsule. Then drill 4 countersink holes about 1/2" in from each corner, for the wood screws.
For parts B and C, cut a 2-1/8"-diameter hole in each center. These holes will house the bottom part of the capsule. For part D, drill a 3/8"-diameter hole in the center, which provides a guide for the spring.