I have downloaded all Phoenix STL files available. After disassembling the left top corner I realized that mine was totally different than the files in the ZIP. I accidentally broke off one of the bearing holders, so I needed to reprint the part.

Here it is re-engeneered.

I have not printed it yet, but will do so in 10 hours, when the print is done....

EDIT 1: 08/16/2015
I have just printed the part and noticed a few things did not fit, like the z axis rod.Somehow I made it 15mm instead of 12mm. and the radius needed to be changed on one of the pulleys, because the belt would scrape the walls...

Also the 8mm rod has nowhere to go. I just started the hole but forgot to cut it an an angle... Version 2 coming soon.

EDIT 2 : 09/07/2015
I have just uploaded a new version with changed diameter and added a hole on the side for a t-nut bolt. I've also changed the arc radius so the belt has more clearance.