I’m running a Taz 5, which has been great for the longest time, but my latest print kept birdsnessting, and it’s become worse and worse to the point where I can’t even get the filament to extrude without cranking the heat to almost 300, and even then it doesn’t work very long and just starts putting out broken lines or nothing at all. I feel like there must be something wrong with the heating system, but I don’t know enough to even figure out the problem, let alone fix it.
Check the setscrew on the small gear on the extrude, and using an inexpensive non contact infrared thermometer from an auto parts or tool store make sure the hotend is actually getting as hot as it should be. It could be mechanical or electrical. Also check the bearing on the idler arm and the two on the hobbled bolt and make sure everything still moves correctly. The non contact thermometer should run you $35ish.
I agree with piercet. Get a IR thermometer and check the temp of the heater block. Sounds like a bad thermister. Inspect the wiring and check that all the toolhead plugs are snug.
A few more questions. If you do a cold pull on the filament, are there teeth marks from the hobbed bolt? Any filament shavings around the filament opening in the extruder body (big plastic parts where the filament passes)?
The hotend is actually pretty simple to service. Basic hotend components:
- Heatsink - top portion of the hotend with fins
- Heat block - bottom aluminum block where nozzle attaches
- Heat break - tube that attaches heatsink to the heater block
- Heater element - round cylinder with the thickly insulated wires
- Thermistor - covered under the aluminum plate on the heat block
If the thermister is bad, buy a new one and replace… Likewise the heat element. I think you can get parts from MakerFarm.