I was trying to print a lot of things on my CR-10S with NinjaFlex and got tired of it binding in the long bowden tube. Even on a normal filament I occasionally got bad prints because the tube had pushed out of the extruder for some reason. The mechanics of the Creality extruder/bowden assembly seem like a pretty poor design to me.
So I started to design a direct drive system to move the extruder stepper above the hot end and limit my bowden tub to less than an inch. Though I have pretty much replaced all of the printer's original extruder and hot end parts, I wanted this to generally reuse all of the parts that came with my printer when I bought it. The resulting thing comes in two parts:
1. The main motor plate that is sandwiched between the existing carriage plate and the hot end. This also holds the stepper motor and extruder parts and includes a harness for the hot end cables. (see photos)
2. A replacement plate for the X-axis limit switch. This is necessary due to the added thickness of the direct drive plate so it can make contact with the switch.