This is an easy to build catapulter expansion set.
You can also use your imagination to build your remixed version.
The new pieces allows you to move the catapulter arm up and to stretch the elastic rubber and to shot thanks to the trigger.
One thing that I didn't made is to create the lifter box with some cartoons.
I think that is better if you create your catapulter box by you own, in this way you will have fun and you will increase your imagination.
Obviously you can also combine the prices in different way to create very interesting design, the only limit is only your imagination!

I want to apologize if same pieces which you see in the picture are not as the pieces .stl you can download because I have printed tham before realizing that the contest doesn't allows me to do so big pieces.
Anyway I have uploaded some pictures that show you how to obtain tham.
All pieces of my design can enter in an area of 10x10x12.5cm

PIECES THAT YOU NEED:

(downloadable from the sets of official thikfun )

5.5” Rod (3 piece)
7” Rods (3 pieces)
Extra Long Connector Plate (2 pieces)
spool (1 pieces)
Hub caps (26 pieces)
Hole Punch (1 pieces)

(pieces invented by me)

C (2 pieces)
D (gomma ruota v1) (4 pieces) or D (ruote v2) (4 pieces)
F (cerchione) (4 pieces)
T (manovella)(1 pieces)
Q(1 pieces)
P(1 pieces)
Catapulta(2 pieces)
Coso catapulta (1 pieces)
Elastic rubber(1 pieces)