New Improved Creality CR-10 S4 Filament Sensor Assembly Project

After have used my Creality CR-10 S4 3D printer now for a good portion of this year I have finally gotten around to making one last change (hopefully) to the setup for the printer.  This being the filament out sensor that came with the printer.  There is really nothing wrong with the sensor itself as it does the job very well of letting me know that I need to change filament when I am printer something rather large. The mount for the sensor is designed well enough to make it work but is poorly designed in the way it is mounted to the 3D printer. 

Pictured above is the sensor that is used on my Creality 3D printer. I am sure that this is used on all models of the Creality line and so all the people that use these printers have experienced the same issue with this setup.  At least I assume this is the case.

 In the housing of the sensor there is nothing more than a small switch that is turned on when filament is fed through it to be printed. Once the filament has passed through the sensor the switch is turned off and stops the print.  Great!  Just what I need for my big prints.  But the problem is the flat section of the housing that you see extruding out to the right lower base of the square shaped sensor housing. This flat section is simply slid on to a flat plate on the 3D printer where the extruder stepper motor is mounted.  This is all well and good as long as you do not have a large part to 3D print. 

If you do then the vibration of the machine slowly loosens this assembly to the point where it will eventually come loose and dangle on the filament that is being fed into the printer.  Not a good thing to have happen while printing parts. 

In the images above you can see the computer model I created to show you what this sensor looks like when it is assembled and taken apart.  At the bottom (in yellow) is the mounting for the sensor and the two flat plates that are slid on to the stepper motor mount.  Above this part is the sensor (in black & white) with a little arm to turn on and off the sensor on the left and the connector socket on the right.  Next up is the cover for the sensor (in blue) and finally the screws to secure the cover to the assembly.

To make a more secure mount for the filament out sensor I designed a new assembly as pictured above. The new assembly eliminates the lower portion of the original mount and replaces it with a taller rectangular base that is attached to the 3D printer using 10-32 bolts that are 2 1/2 inches long with additional locking nuts.  These bolts replace the bolts that hold the rollers for the "Z" axis of the printer on the left hand side of the machine. 

I saved the original top cover and mounting screws for the new assembly along with the sensor switch needed to make this all work.  In the image above you can see these parts along with the 10-32 bolts and nuts and two small spacers (in red) that allow clearance for the assembly to keep it  away from the stepper motor  that is used for the "X" axis on the machine.  Another thing that took me some time to get designed right was the upper portion of the new lower section of the assembly.  This had to match the lower portion of the original mount so that the sensor switch would mount and work properly. 

This took a lot of trial and error prints to get it right and needed to be done to make the new assembly work just like the old assembly without the issues of it falling off of it's mount. 

I also had to be very careful to get the placement of the top portion of the new assembly in the exact location of the original sensor so as to not mess up how it all worked in the process.  So far I think I have it pretty well nailed down so I think I am good on that point.

Pictured above is the new sensor out assembly mounted into my 3D printer.  The red arrows indicate where the 1032 bolts are mounted that hold the sensor along with the rollers that guide the "X" axis rail on the left side of the machine.  This rail moves up and down for the "Z" axis on the printer.

In this photo you can clearly see the new sensor mounted at the back of the machine with a white arrow pointing to it.  The red arrow is pointing to the stepper motor for the "X" axis that the new sensor assembly needed to clear to be mounted properly.  The green arrow is pointing to the upper 10-32 bolt that holds the new filament sensor assembly in place on the machine. 

This new setup will be a big plus to my 3D printing as I will not have to keep fussing with the filament out sensor every ten minutes to make sure that is still in position where it needs to be.  With this new mount it is securely fastened with lock nuts and does not interfere with anything else on the machine while it is running. A big improvement in my book.  

Just one more thing that the people at Creality hopefully will take notice of and put on future machines that they produce. "Hey Creality! If you do make this change please let me know. I can  always use another 15 minutes of fame."  At least it will make my day anyway.