Zip Tie Type Bearing Holders For Reprap Pro Huxley

I had a problem with the push fit type bearing holders in the stock Reprappro Huxley breaking every time (3 times) I tried to insert them. In truth the problem most likley lies in one of the following things

1) me being clumsy
2) not properly deburing the inside face
3) More than likely my slicing settings where no correct ( I have since found setting a fixed extrusion width ratio in Slic3r to have improved its output no end)

But for all you other clumsy fellows I went down the route of