Space Invasion!!

Horrible monsters from outer space are coming to attack us!! -And our only defense is you and a few old beer cans. You gotta shoot them down and you will get a reward for saving the earth. In Addition to the printed parts, you will need two rubber bands, and a bag of marshmallows to complete the toy. The toy needs to be printed in two rounds, or more if you want different colors on the objects. The UFO fits in the 21cm*21cm*21cm space when rotated 45 degrees and the rest of the parts can easily be printed on the same plate. There has to be printed 3 of the pinShort, 4 of the pinLock and just one of each of the other .STL's This is the first object I have created for 3D printing and I have learned a lot. Some support structures will be needed on the monsters I think, but otherwise I have tried to make it as 3D printing friendly as I could without having any practical experience with 3D printing. All the objects are modeled in Modo701, exported as .STL's and converted to STEP with FreeCAD. The STL's have been re-saved with MeshLab If anyone prints this I would love to see some pictures :)