trouble with ReFlow rpla

[Rob_etc 0]

Hi

We have a several month old Ultimaker S5, and have been trying to use ReFlow RPLA on some long print jobs (1.5-2.5 days). After a period of time (1 day, 3 hours, or even just 1 hour) the print pauses giving the error that the material is empty, though it is clearly not. Normally, the job can be restarted and continue with small errors (minor issue for these prototypes, but wouldn't be acceptable for a product) at the pause line until it happens again.

 

These are our guesses for the problem so far:

• feed motor (best guess) - now used both nozzles with similar problem. though one is worse that then, perhaps because it's been used more (?). at time of error location the filament in the motor is rougher than elsewhere
• flow sensor - ultimaker suggests to turn it off, but this allowed for catastrophic errors for the print job when turned off
• flow rate - turned it up to 105%. seems to help.  errored less often
• impurities in the material - difficult to judge
• cardboard spool causing friction that the S5 sensors detect - loosened filament on spool. still had error

 

Does anyone have experience with this? Or have the same problem? Or is it a more general flow problem?

 

Thanks for your help and thoughts!

Rob