Storage handle screwdriver for magnetic chuck.

This is a refined, fatter version of the [storage-handle screwdriver](http://www.thingiverse.com/thing:660843) I did previously. Works well with the magnetic shaft, like included with [this bit set](http://smile.amazon.com/Enkay-3033-33-Piece-Security-Insert/dp/B0009U6AB4/) or something similar that often comes with a cordless drill set; this gives you a screwdrier with a handle for better control and portability than an electric drill. It supports use of a [3/16" cylindrical magnet](http://ww