I just took delivery of a Mini 2 this week.
I am working through the quick-start manual and trying to print the Rocktopus test print through Cura
I am not able to extrude (or retract) filament. It appears to me that the stepper motor gear is not engaged with the extruder hobb gear (large plastic black gear).
The stepper motor gear turns fine on retract and extrude command. The hobb gear turns freely but is not engaged with the stepper motor gear.
I would appreciate any direction or advice you may be able to offer
The “hobb” gear is the feed gear (metal) with the teeth that grip the side of the filament. It is tied to the larger black gear for a gear reduction (to give the stepper motor stronger mechanical advantage). The stepper motor has a shaft with a flatted side and there’s a smaller gear with a grub-screw that snugs this to the flat. If the black gear can spin freely even if the motor isn’t turning, I’m wondering if the grub screw wasn’t tightened down on the shaft.
As this sounds like a new printer, I don’t recommend you disassemble the print-head on your own. You may want to phone LulzBot tech support to ask for guidance.
The print-head is attached to the x-carriage with just three screws and one wire harness (this makes it pretty easy to remove) – although that’s not counting the cosmetic cover on the print-head (I think the cover is held in place with 3 screws).
If you’re interested, the document that explains how your AeroStruder print-head is assembled is located here: https://ohai.lulzbot.com/project/lulzbot-mini-2-aerostruder-assembly-and-packaging/mini-2/
BUT… don’t disassemble it … phone LulzBot support. That document is just for your reference. If it wasn’t under warranty… you could use those steps.
Try a few turns on the idler screw to ensure the filament is being gripped by the hobbed bolt. Then heat up the hotend (through Cura) and try to manual extrude by rotating the gear (motors need to be off). If that works, then try to extrude through Cura.
Thanks very much for the link
What I am seeing on the AeroStruder unit is the stepper motor gear is not engaged with the large black gear connected to the hobb. It appears to me that the stepper motor gear has moved on the shaft towards the motor which suggests the set screw is loose or missing
The link was very helpful in understanding how the parts are put together
I have contacted support and sent them a video - just waiting to hear back on possible options for resolution