Worm Gear Box

This is Worm Gear Box working by Stepper Motor 28BYJ-48.
I am just beginer. So a lot of changes and tries made this last version.

If you have any idea, please update this.

Thanks,

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Aug 02, 2016 : I have updated a little.
Aug 04, 2016 : Lower Case Solid Inspected
Sep 18, 2016 : Upgraded box with just 2 part