What would cause the hotend to stop heating in the middle of a print?  

Re: What would cause the hotend to stop heating in the middle of a print?

Dang, sorry that long print failed.

Things that would cause heating to stop assuming the gcode is sane:

Blown heater fuse (if you’re heating now, it’s not the fuse).

Bad heater connection, like a frayed cable, would more likely either blow fuse or give you wild temp swings.

Beyond that I’ve never personally seen a machine just decide to stop heating...maybe a firmware bug but that’s pure speculation; update your firmware if you haven’t for a while and maybe make a note of the firmware version you’re running.

It *could* in theory be an Octoprint communication issue, if you were printing from octo and not SD card, but just another guess.

To eliminate that as a possibility, print from SD and monitor from octo instead.

Re: What would cause the hotend to stop heating in the middle of a print?

Thanks, I tried again and the same thing happened at the same time so I am thinking something happened to the gcode since the last time I printed it. The hotend was set to 0 and when I would go to tune and change it, it would reset to zero almost immediately. Also tried to do it through ocotoprint.

Anyway, I re-sliced it, lets see if it works this time.

Re: What would cause the hotend to stop heating in the middle of a print?

If you are on the latest firmware, there seems to be an issue with the 3.5.0 release as there are numerous threads on people experiencing issues with the printer stopping to heat in the print and drops in temps during a print.

There is a thread in this subheading about 4 posts below yours about this and a github issue about it being researched.

I suggest that if the issue continues for you, downgrade to 3.4.1 until it is fixed.