It happens when a filament spool reaches its final 25% and when it’s less straight than when the spool is fresh. The tighter curvature of the filament now entering the sensor falsely triggers the sensor into runout mode. This causes a halt in the printing, often resulting in failed overnight prints. This needs to be fixed.
Suggestion to SOVOL:
Increase the exit nozzle 30, 40mm on the runout sensor forcing a more straight line of travel as the filament goes through the runout sensor.
Before, I had the sensor mounted according to your pictures, and it was worse. The sensor kept halting my prints. Mounting the sensor in a fixed / rigid way, without the free range of movement solved the problem. I no longer get false runouts and everything works perfectly now. The filament’s flow and movement through the now rigidly mounted sensor can no longer force the sensor into an unfortunate angle where the shape and curvature of the filament triggers a false runout.
I made the video to visually demonstrate that the sensor still contains the flaw despite the above workaround. In due course, I’m sure other users will experience the same symptoms as described here.
I’m currently improving the design of the runout sensor extension to work better. I discovered that in some rare cases when the extruder is at an extreme left / right (X) position in relation to the spool & sensor, a false runout can still be triggered. I will post here as soon as the V2 is tested and ready for upload.
