mcbeen.com

I’ve gone through a few revisions of the buffer, but it’s got a few design issues I have not been able to resolve. Part of the problem is loading new filament into it is very tricky, but the path the filament takes is to tight of a u-turn. I’ve gone back to the drawing board and am trying a new idea. Instead of mounting it on the side or rear of the printer, it will be mounted vertically on top.

The new buffer has the extruder above the run-out sensor. The idea is to have the extruder pull filament from the spool, and push it down to the run-out sensor. The “buffer” is now a short length between the extruder and the sensor. The extruder is not rigidly attached to the buffer, and slides along guide rails as the buffer fills. A switch on the extruder rides one of the guide rails, and triggers when the buffer is full.

The buffer extruder is mirrored off of the main extruder in the toolhead, but is tuned to be slightly faster in order to fill the buffer. Ideally, they run at the same rate most of the time.

Unfortunately the plastic guides are not working well. I’m going to pickup a couple 100mm rails with sleds to reduce friction, and keep everything aligned. Here’s a video of it working.