Customizable Battery Case with locking tabs

This is a remix of walter's customizable battery case with the support columns modified to have locking lips on them to keep the top and bottom more securely locked together during travel. I have only printed and test fitted a 2x4 design for 8 AA batteries (STL files included) but nothing else. Enjoy...

All you need to do to customize it is to modify the following lines:

_part = "bottom"; //[top, bottom]

// AA-14.6mm, AAA-10.7mm, 123A-16.9mm, CR2-15.6mm
_batteryDiameter = 14.7;

// height of the battery recess (height of top and bottom piece should be equal to or slightly larger than the battery height)
// AA - 50.5mm
// AAA - 44.5mm
// CR123A - 34.5mm
// CR2 - 27mm
_insideHeightTop = 21; // 21 for AA
_insideHeightBottom = 30; // 30 for AA

// number of batteries across
// NOTE: having 1 x 1 design will result in no interlocking lips
_columns = 4; // [1:50]

// number of batteries deep
// NOTE: having 1 x 1 design will result in no interlocking lip