Ventian Blinds Cam Replacement

The venetian blinds in our house (we have 15 or so of them) are quite nice, being thick wooden blinds.
However, they all have a common flaw: part of the mechanism that enables them to rotate is a small plastic cam that holds the strings that has failed on every one of the blinds.
There are up to four of these small cams in each blind unit: we discovered to our dismay after moving in that nearly all of them had failed, and had been duct taped back together to make them look like they worked.
This works as a short-term fix, but the duct tape peels off and fails after a month or so, so we were constantly fixing these things.
Makerbot Replicator 2 to the rescue! I was able to extract the part from the blind assembly, and using my CAD software, designed a replacement.
I made the part thicker in the area that was failing, and also thickened the walls of the part to ensure its durability. It took a few iterations to get the size of the hexagonal hole correct (photo 2 - the cam n