Duk’s asked me if I could take a look at a slow heating 3D Printer that never gets up to a usable temperature. Turns out one of the two heater resistors was open.

they are just 6.8 ohm 3W resistors stuffed in with RTV Copper.

luckily I keep spares on hand for my printer. I cleaned out the RTV and found a 12V 40W cartridge fit perfectly.

its 3.6 Ohms so it is a perfect match.  the two 6.8’s were in parallel so that was 3.4 Ohms

i would have liked to drill and tap a hole for a set screw but there no meat on the sides…

it was a pretty snug fit and a drop of Permatex should hold it fine.

It seemed to heat quickly but had a lot of overshoot so I reran the pid calibration and got that tuned in..

Heater Upgrade for a SeeMeCNC