Bowden Flexible Extruder Upper

I slightly modified the original Solidworks file to put a small protrusion in the middle of the ball bearing guide of the stock TT extruder when assembled. This has allowed me to print a little faster with no flexible filament bunching behind the ball bearing guide like I experienced in the original when printing. I also decreased the counterbore for the socket head cap screw in the original so the stock fasteners don't bottom out in the motor before securing the extruder upper securely to the motor mount.