NOTE: This is a revision of my original tool. I've added a collar around the button of the bottom tool. Recently when I was using it, there was a slight side pressure and the part shot off, burying itself among cables on the floor. The collar is to help both in positioning the part and holding it in place under pressure.

If you own and use a CFS, you will eventually encounter a filament jam where the filament will not retract. You can try to pull it backwards out back to the reel, but it won't budge. Most of the time, you're forced to cut the filament at the reel, then pull it through the CFS, leaving you with several meters of scrap filament. It's usually too short to use in a project.

I went through this enough times to decide that there has to be a better way. Through some trial and error I found it. This is a two-piece system to help you release the filament so you can back it out of the CFS back onto the reel.

To do this, none of the filament can be in the extruder. One way to tell this is to disconnect the PTFE tube from the back of the printer and pull out the filament. If you can do this, you're good to go. Here's how to do this:

1. Place the bottom tool under the CFS, with the black lever underneath resting on the peg (See Figure 1)

2. On the front, push the lever in front of the reel in and put the spacer in front of it (to hold it back) (See Figure 20.

3. Start winding the filament back onto the reel. If it's not freely backing up, you may need to rest an arm on the CFS to push it down so that the bottom lever releases the filament. Don't let it tip, or it may slip off the peg.

4. Don't forget to remove the tools! Otherwise, the filament won't feed (ask me how I know this)!

CFS Filament Backout Tool 1.1

0.2mm layer, 2 walls, 15% infill