I’ve been fighting with some filaflex 82A all week, but I finally got it printing right by setting the flow rate to 1.7x. I’m running pass 2 of the flow rate test as we speak,
I know, it sounds crazy to me too.
It seems totally wacky that i would need almost double the normal flow rate. I’ve never had to do that in the past.
This totally messes with the volumetric flow I prefer to use over regular mm/s speeds.
I thought maybe the filament was slipping or grinding in the extruder, but experimenting with low speeds and adjusted extruder tension have pretty much ruled that out.
I’m already printing at 235F, so I don’t think I can melt my way outta the problem with higher temps, so I’m out of ideas.
Happens with soft TPE/TPU if you have a lot of drive tension and single sided drive rolls - the filament gets compressed going through the extruder, stretches between the teeth and you end up driving far less filament than it actually should.
However, that seems excessive, unless you cranked the extruder pressure up instead of down - my other TPU optimised printers are generally up around 1.25-1.3 with similar drives to the A1, my P1S is around normal filament settings with the dual drive gears, (and an upgraded extruder gear and tension backed off).
235c isn’t a whole lot if you’re trying to print TPU fast, I’ve had profiles running for years that run TPU at 250-260c to print with any sort of decent speed and strength, 235 works if you have a long hot end and CHT nozzles to get enough heat in to keep the hot-end pressures low.