hot end keeps shutting off

hot end turns itself off mid print?

what would cause this I have done about 7 or 8 prints since I swapped out my heater cartridge no problems at all now all of then sudden a couple of times my heater has shut itself off on its on.

I felt the mosfet that was connected to it and its warm but not hot and there are no shorts in wiring. I also checked the g code to see if someone was pulling a prank lol. and I can't seem to find any issues

Check to see if you are exceeding the firmwares max temperature. I had this problem when I started using the cartridge, it would heat up so fast that it would overshoot the target temperature and overheat which would shut it off. Thats why I limited the current to heater. Let me know if that helps, I will try to think of other things that would cause that. Have you checked for broken wires or bad connections?

Crussell Wrote:
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> Check to see if you are exceeding the firmwares
> max temperature. I had this problem when I started
> using the cartridge, it would heat up so fast that
> it would overshoot the target temperature and
> overheat which would shut it off.

Your host software's console should say something like "ERROR: maxtemp() triggered!" if that was happening. This could also happen if the hot end thermistor's wiring got knocked loose a bit during the upgrade and the electrical connection is spotty. The millisecond during which the circuit is broken causes the hot end temperature to read zero, and the firmware will kill the print.

I dont remember it saying that but at the time I was using Sprinter. It did it almost everytime I heated it up til I changed the current. I know thats what was happening though, just as soon as it hit 275c it would shut off unless I played with it a little bit to get it to heat up a little slower til it stabilized.

the printer keeps going extruder and all but the hot end shuts off its not saying anyting on the log about max temp I am still printing around 230 cause I have a jhead

Could be a problem with the thermistor (if your using a thermistor). I had a problem with my solder joints melting when it got too hot and shutting down the heater.

Would a short in the thermistor also be related to why I sometimes see random thermistor readings ? I bet the wire just has a short in it I will check it and let u guys know if that does the trick

yes a short would do it. if a drop in reading is only for 1 sample the temp drop may not show as much in the prointerface terminal or on the lcd readout, but it will register as a flag for the firmware to shut down the machine. if one sample is above the max temp, this is enough to stop the machine. if its below min temp the same thing will happen as well.

at this point I think I just need a ultimaker or send someone my printer and let them work all the bugs out of everything