QUBD : Bearing holder to prevent z-rod wobbling

This is redesign and mix of
http://www.thingiverse.com/thing:289966
http://www.thingiverse.com/thing:754526

The changes are

• Instead of the 608zz ball bearing, I use the flange bearing. as my local HomeDepot had stock.
  http://www.homedepot.com/p/Crown-Bolt-3-8-in-x-5-8-in-x-1-in-Bronze-Flange-Bearing-57738/203537359
  I hope this longer shelve provides the z-rod even less room to tilt.

• Instead of bridging very long lid (40[mm]), I separate them into 2 parts (body and cap) to sandwich the handle bar (PART:SS) with m3 screws.

• Arrange a pocket on the bottom (2nd picture), to keep the maximum travel z-distance of my gantry. (http://www.thingiverse.com/thing:952796 )

• Instead of drilling the stock MDF part, I use the sandwich mechanism to attached the body to the handle bar.

The results are ---

• x:surface : The jagging significantly reduced. Almost disappeared. AMAZING !!
  Although it's hard to take pictures representing my surprise, the 3rd picture is my best effort without a macro lens ( from top -- with this bracket, 2nd and 3rd without )
  Or the result looks like this http://www.thingiverse.com/thing:938425 (from different design)

• y:surface : A little jagging still observed ( I think I need to improve the y-table controls the other day)

Also, I don't see the handle bar shift any more.