With extruder issues, you want to start at the source spool and work your way down to check things.
- Can the filliament spool move freely, or is it caught on something?
- is the filliament feed tube allowing the filliament to move through freely with no restriction (spcifically are the zip ties holding the tube in place too tight?)
- Is the filliament binding where the idler filliament guide contacts the upper extruder body? (If so, sand some material away until it is able to move freely
- Is the hobbed bolt grinding chunks out of your filliament?
A. If yes, you have either a temperature or force issue for feeding.
B. If no, your small gear on your NEMA motor isn’t tightened at the set screw all the way or your main gear is installed on the hobbed bolt incorrectly.
If you are getting chunks ground out of your filliament, there are several possibilities. One is that your idler is either not tight enough, or too tight. Not tight enough will wear away filliment slowly and won’t move it much. Too tight will immidiatly rip chunks out of the filliament. A clogged filliament chamber can also do this. Remove any excess shavings, make sure the bearings are not impacted, and clean the hobs of the bolt out with a toothpick or other pointy object.
If all that looks correct and you still aren’t able to feed filliament through the hot end, I’d suspect that it is not actually getting up to temperature. That would be really rare, and usually you would just see a working or dead hotend, not one kind of working unless the temperature was set wrong. If you are extruding ABS at 230 degrees C, it should come out with almost no resistance at all. If you try and print too close to the bed for the first layer and don’t catch it in time, that backpressure can cause the filliament to stop and get chunks ground out of it… If the extruder itself has a malformed filliament channel that can cause binding and cause the grinding issue, Stick a piece of filliament in that section and see if it moves properly. if it sticks, grind the hole out bigger on the ABS plastic exruder body itself (not your hot end)
Another troubleshooting step, dismount the hot end entirely and run filliament through the extruder. if its moving and moving properly, the trouble may not be there.
If you can, take a bunch of pictures of your extruder, the hot end, the idler chamber, the gears, etc. and post them here. maybe we’ll get lucky and spot the issue?