Recently I been having this issue where the extruder will not get up to 210 degrees. It will get to about 208 then fall back down to 204, then back and forth.
Meanwhile this is happening, the filament starts to smoke. So my thinking is maybe the sensor is not reading the right temp, etc?
Any help would be appreciated.
djcs
2
Hey John,
Check that the sensor is still in the heating block.
On my original heat block, the sensor just sat in there and was held in by the tape being wrapped around the
heater element wires to hold it in place. Thankfully I was able to catch it before it cause any problems.
I have since bought a new heat block that uses a grub screw to hold the temp sensor in place.
The tape is also still used so as not to cause too much tension etc.
Do you have a thermal temp gun?
I would suggest you get something to read the temps externally.
This will easily help diagnose these sorts of problems.
DJ
DJ. Thanks for the info. Come to find out that the heating element was almost out of the hole and it brought the sensor out of the hole. The sensor was still close enough to the block that it picked up heat. Once screwed back in, no issues. Now I just need to relieve stress from that cable that runs to the motherboard. Thanks!
gilman
4
I had this same issue and it is good that you caught it. My sensor pulled out completely during a print and even though Marlin eventually cut if off due to thermal runaway it wasnt fast enough to prevent the heater from continuing to heat up so hot that the teflon in the hot end burnt and clogged my nozzle. I had to buy and reinstall a new hot end assembly. The one I got has a grub screw but it doesnt quite reach far enough to secure the sensor any tips to get it to work?
