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:
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)
- 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.
Printed in PLA @ 195C with a bed temperature of 60C. It's a pretty big print, so make sure the bed is hot enough to ensure that it sticks properly during printing
Installation should be straightforward (see photos). The direct drive stepper plate is held by the existing hot end and fan shroud bolts. Make sure to add a suitably sized piece of bowden tube between the extruder and and hot end - the length of this will vary depending on the parts chosen.
I have replaced the original screws with better ones and mine are probably longer than the original screws that held the fan shroud and hot end. You may need to do the same - they are all M3 screws if you didn't already know
My extruder is from MacEwen3D (https://macewen3d.com/products/mk8-extruder-aluminum-drive-feed-for-cr-10-cr-10-s4-and-cr-10-s5) and works amazingly well. The original extruder should work as well however.
My hot end is from Micro Swiss (https://store.micro-swiss.com/collections/creality-cr-10/products/300-c-flexible-friendly-hotend-kit-for-cr-10-printers) however the original hot end should work without any issues
Don't worry about the added weight of the stepper motor. It sits right above the x-axis rail and should not pull the carriage off-balance. Stepper vibration isn't a measurable factor while printing.
- Make sure the wire for the stepper motor is long enough to reach across the bed. In my case it was just long enough but depending on Creality's assembly accuracy yours may be shorter and may require an extension.
I built this from scratch using Fusion 360 (thank-you Autodesk!) and sliced it with Simplify 3D. Total implementation time, including design and printing many prototypes was about 30 hours.