the TAZ seems to work mostly fine but there is a problem where the filament extruder keeps stopping while it's trying to extrude - like the filament is too hard for it to push, so the motor doesn't have enough torque.

the spring tensioners adjustment is not the problem - there is no adjustment point at which the motor doesn't either slip (and fail to push the filament) or catches and can't turn.

if you keep hitting Extrude in the printer control program and you help the filament along it keeps going, but it can't continuously extrude without help - it goes and then gets stuck again.

I can't figure out what the problem is.  This is with the white filament and the nozzle is at 220 degrees which should be plenty hot.

anyone have any ideas?