The number of pieces needed:
-arm x 1
-thumb arm x 1
-top plate x 1
-bottom plate x 1
-20mm fingertip x 2
-20mm finger x2
-30mm fingertip x 3
-30mm finger x 2
-40mm finger x 5
-finger connection x 4


Order of assembly of fingers(from base to fingertip)
Thumb: thumb arm / 40mm finger / 30mm fingertip
Index: finger connection / 40mm finger / 20mm finger / 20mm fingertip
Middle: finger connection / 40mm finger / 30mm finger / 20mm fingertip
Ring: finger connection / 40mm finger / 30mm finger / 20mm fingertip
Little: finger connection / 40mm finger / 20mm finger / 20mm fingertip

Tips for 3D printing:
In order to increase the overall strength, i would recommend i high infill.
Support structure is only necessary for the top plate piece.