Aluminum angle iron for Y-axis support

**Update 2-5-17**
noticed I was still having bed leveling issues, I replaced the y-carriage with a new one made out of Aluminum and 3mm thick ( https://www.amazon.com/gp/product/B01MUAMRN7/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1 ) instead of the 1mm thick steel plate that comes on the machine - What a Difference that made. Picture shows the difference of the thickness of the 2 plates vs the heating bed
According to my dial gage ( http://www.thingiverse.com/thing:2040422 ) the bed is now