We just ran the first tests in flexible filament. FlexPLA works wonderfully even when printing at normal speeds of 50 mm/s. It looks like it prints as smoothly as normal PLA so you can amp up the speed considerably. Filaflex is too flexible and gets stuck in crevices in the extruder, similar to what happens in Lulzbot machines. So we would need to modify the gear drive to make that work.

Soon we will be testing high speed printing with a 1.0mm extruder.