@T3P3Tony I don't currently have another means of measuring temperatures above 100C, which is where the issues start happening - the heating rate begins to level off until an asymptote at 200C . However, I know that I was able to melt PLA at around 215C (according to my thermistor) before changing the thermistor with the thermocouple , and I haven't changed anything else, hence why I think it is an issue with the temperature sensing or conduction of heat.

Hi all,
I purchased an unencapsulated K-type thermocouple from E3D, and have crimped a metal cap onto it to avoid contact issues. I configured it using M305 P1 T"K" X150

It appears to read the right room temperature, but the measured temperature appears to asymptote at 200°C as I run it through a tune using M303. The heater was working fine before and easily reaching 250°C, which makes me suspect that the temperature being measured is wrong, not the heater and the fact it doesn't give short to other wiring (which were occuring without a capsule) suggests it isn't the capsule itself that is the issue, but I am not sure.

I have inserted the thermocouple into the printer as shown in the pictures below, which sticks out slightly as the cartridge maybe 5 mm too long. I suspect either it is misconfigured in software or that there is an issue with heat conduction. I saw on another thread it can be worth grounding the cartridge can help.

I'd love to hear your suggestions so I can get printing again!

I am using a Duet 2 Wifi with RepRap 2.

Thanks @droftarts, you may be right that it could be a wiring issue. The thermocouple is bare and I don't have any kapton tape at the heat block. Funnily though it is working, sometimes. The thermocouple reads 2000*C if it is touching the heat block when the Duet starts, but if I start the Duet and then insert the thermocouple it works fine (even after using the emergency stop).

I wasn't using insulation (e.g. kapton) before but it was working without having to do this cheeky tricky. Maybe I got lucky and there was enough dirt/resistance? Are there any alternatives to kapton tape?

Hi there,
I have had a Duet3D Wifi 2 with a J type thermocouple, and all was working fine until doing maintenance work on part of the printer. One of the terminal blocks was damaged by the thermocouple cable being pulled, so I switched to using the second thermocouple channel (T1).

I changed config to use M308 P1 X151, but I am getting a "sensor short to other wiring" error.
Steps to solve issue:

1. Tried switching the cables (in case the red/blue colour coding was US instead of Dutch/German)
2. Tried inserting a 330 Ohm resistor instead of the thermocouple. The Duet gave a reasonable temperature reading of 25 C.
3. Checked the thermocouple wires at the hotend side and moved the metal shielding up so it wasn't touching the heating block.

Also, I don't know if I am just being thrown by the phrasing of the error message, but if the terminal is empty the Duet thinks there is a sensor short.

Any suggestions?