Bed Thermal Runaway
My printer stopped and provided the Bed Thermal Runaway warning.
The red light that signals that the bed is heating up sometimes comes on and sometimes goes off. If you push around the sleeve that is connected, sometimes the light comes on (sometimes you see sparks). Do I need to replace the heatbed thermistor set?
Thanks...Jeff
RE: Bed Thermal Runaway
The thermistor is most likely ok. You can check the internal resistance with a multimeter (100kohms at 25 degrees C. room temperature).I think that the wires to the printer board have are faulty.
wbr,
Karl
Statt zu klagen, dass wir nicht alles haben, was wir wollen, sollten wir lieber dankbar sein, dass wir nicht alles bekommen, was wir verdienen.
RE: Bed Thermal Runaway
If you are seeing sparks, it is not the thermistor. Look at the connections and make sure that the bolts are tight for the power cables.
RE: Bed Thermal Runaway
RE: Bed Thermal Runaway
https://www.prusa3d.com/product/heatbed-einsy-power-cable-screw-attached/
RE: Bed Thermal Runaway
I would replace that wire assembly with Flexible silicone insulated wire 16AWG. using crimped on connectors at both ends
and I would ensure that the sleeving for the wires is firmly clamped under the cable clamp to act as a strain relief.
My bed cables also have a 3mm Nylon re enforcement filament, to aid strain relief.
joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
RE: Bed Thermal Runaway
I would replace that wire assembly with Flexible silicone insulated wire 16AWG. using crimped on connectors at both ends
and I would ensure that the sleeving for the wires is firmly clamped under the cable clamp to act as a strain relief.My bed cables also have a 3mm Nylon re enforcement filament, to aid strain relief.
joan
If you don't have the crimp tools, talk to your friends and neighbours, they may have the crimping tools and connectors.
The nylon is a good idea. If you don't have some nylon filament, a zip tie could be used as well but you need some flexibility in all directions and a zip tie will put a restriction on one direction so watch the angle so it curves in the correct direction. Cut off the large end and the tip. Will help with the vibration. I may change mine today when I put the printer in the enclosure.
I also saw a different housing on one of the different 3D model sites that provides a longer strain relief behind the connector, just for this reason.
RE: Bed Thermal Runaway
A car repair shop may also crimp the ends for you.
regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
RE: Bed Thermal Runaway
@jeffkahn72:
I had a similar problem with melted wires right at the beginning (2 weeks old MK3). After I replaced the 24V wires with flexible silicone ones, the printer has now been running for over 5 years without any of the above problems. For this reason, I would follow Joan's tip 👍
wbr,
Karl
Statt zu klagen, dass wir nicht alles haben, was wir wollen, sollten wir lieber dankbar sein, dass wir nicht alles bekommen, was wir verdienen.
RE: Bed Thermal Runaway
Did my zip tie suggestion today when I put my printer in the enclosure. See the attached image of the sequence.
I had larger zip ties than what come with the printer so I used one of those. Clamped the one end in the cable clamp area following the curve of the cable with the Y axis all the way back. Cut to a length that didn't restrict the movement. Tied the rest of it down.
RE: Bed Thermal Runaway
Thanks to everyone for the help. I ordered some new wire from Amazon which should come Tuesday and my neighbor says he can help with a crimp tool. Will update once complete but thanks again for the very helpful comments! Jeff