The Ultimate Catapult Improved

Printing, assembling and tests: https://www.youtube.com/watch?v=fQQTOoDlm3Q

[The Ultimate Catapult](http://www.thingiverse.com/thing:31288) by [roguemat](http://www.thingiverse.com/roguemat) improved by:
- New, stronger pin tabs
- Rubber band plugs that prevent band from falling out
- Scaling parts so they fits tightly
- Fixing mesh errors

I also added [Bucket V2](http://www.thingiverse.com/thing:31449) part by [dan0nator](http://www.thingiverse.com/dan0nator).