3D Printing Public Service Announcement:
There are bad heater cartridges recently introduced into the general RepRap supply chain. - E3D, TrinityLabs and Prusa Nozzles maybe affected.
They exhibit 2 problems:
Incorrect resistance/power output. - Instead of 40Watts at 12Volts, they average around 18Watts - which may lead to poor ability to maintain high temperatures or to print quickly.
Misshapen/Oversized - Out of round, bulged, or oversized from the rated 6mm by up to 0.2mm means that some aren’t fitting in holes intended for these. Previous batches have been very dimensionally accurate.
This issue has struck us at E3D - If you think you have been affected then do not fear - we are already in the process of shipping heaters to anybody who has the slightest chance of having a bad heater. All being sent airmail in the next few days.
I have had multiple (but grapevine/second hand source) info about this same problem affecting the TrinityLabs and PrusaNozzle supply chains. This makes sense as I know for a fact that all three of us are using the same supplier for these heaters.