Heater fault right at start of print?

  • I wanted to reach out and see if I could get some help on this. When I try to start a print it takes a while for the hotend to get to 250c and sometimes will fault out because it is moving to slow. However, if it does reach 250c the second that the nozzle moves towards the bed the temperature jumps to somewhere around 30 - 50 degrees hotter resulting in an immediate fault. I have attached a picture off my duet control right after the fault so you can get an idea of what the temp graph looks like. The hotend is a E3D V6 24v with the default thermistor and the board is a duet wifi. Any help would be so appreciated! Thanks!

    The spike in the graph is the start of the print. I had brought the temp up to 250c to do some testing.


  • @nickmickmlnn Well that's odd. The first thing I'd say is that the spike isn't "real". By that I mean, the time is too short for the heater to suddenly increase the temperature by 50 degrees C. But obvioulsy, the indicated temperature does suddenly jump so it's a measurement error. You say it occurs the second the nozzle moves close to the bed. This might indicate a wiring issue. Have you tried simply wiggling the wires around to see if you can replicate the problem? Another possibility might be a change in Vin voltage as the motors energise and start moving things around, due to a dodgy power supply. If you run M122, it'll show you the min and max voltages. Does anything else happen when the nozzle moves towards the bed. Are there any fans starting up or turning off for example?

  • I had an issue with one of my V6 hotend thermistors where it would get wacky at times....turns out the wires were failing right at the thermistor cartridge and I could make it happen by lightly touching the wires and see it jump. I would start by checking the thermistor out.


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