Hi everyone! Long time lurker, first time poster. I didn’t want to have to bother anyone with this issue, but since Aelph Objects support has been terrible lately (due to moving locations) I can’t rely on them.
I have a Taz 5 with the single v2 extruder. Nothing fancy
For almost a year now I’ve been combating under extrusion and didn’t figure out why until a few months ago. When my extruder temp is set to 205° for PLA (either set in cura, or octoprint, or at the machine itself), all signs point to it having heated up to 205° but when I take a Fluke thermometer with a thermocouple and touch the nozzle I get 170°. It doesn’t seem to matter what temp I set the extruder to, it will always be about 30° cooler than what the machine thinks it’s at. I currently have to have the extruder set at 260° to fool the machine to be able to print PLA.
Attempts to Fix:
This scenario sounds like a faulty thermistor, right? So I went and bought a few and tried each one; same problem.
Realized the 100k thermistors might not have the same beta value and didn’t want to try messing with firmware, so I bought an official Semitec NTC 100k 104GT-2 Thermistor and put that in. Same result. I disconnected it from the harness and measured its resistance at room temp and it’s at 100k, so this leads me to think it’s not the problem. I opened up the rambo box, disconnected the wires to the board and tested them for continuity to the connector for the thermistor, and they were good. I then tested the resistance of the wires and got zero, so they’re fine. Signals from the thermistor should be getting to the rambo board no problem.
Tried replacing the original 30w heater cartridge with a 40w one. Thought maybe it wasn’t getting hot enough and the 40w would be a nice upgrade. No change, except it heats up faster, which is nice.
I did PID tuning after changing out each thermistor and heater cartridge, but no luck. Tried rolling back to the first firmware version the printer came with and doing PID tuning again. Still no luck.
At this point I was running out of options and could only conclude it was the Rambo board, so I got a new one, put it in, flashed it with the latest firmware aaaaaaannnd it’s the same.
Thought maybe the heater block wasn’t transferring the heat from the cartridge throughout the block properly, so I made a new aluminum block and put a new nozzle in it and tightened everything as per the
online instructions from lulzbot, but no luck there either.
Maybe the filament is just dragging in the heat-break or is getting resistance from somewhere? I tried putting a new extruder stepper motor gear in the tool head, lubricating the bearings, realigning everything and reassembling. No better.
Finally, I bought a new block, new swiss 0.5mm nozzle, and put that together with the new 40w heater cartridge and the new 100k thermistor…and I get the same result.
I’m out of ideas. I’ve basically rebuilt the machine and there’s nothing left to change!!
I’m still getting the wrong temps at the nozzle and if it was off by 5° I would be happy, but 30° is way too much!
I’ve spent months trying to get this working properly and I’m starting to think the only solution is the dumpster. I’m losing my hair over this. Anyone have any ideas on how to fix this?