Heater extruder not heating at expected
Had this happen on my last two prints
12 Replies
Usually that's either a thermistor issue, hotend broken, or some wiring issues
Is there a suggested method for determing which of those three?
I heated the hot end back up to 200C and drove the print head around the board doing height maps (sweeps the print head all around the board) but saw no deviation in temp. (my way of testing wiring).
Wiring seems good...so thermister or hotend I am guessing.
Yeah, the intermittent issues are always the worst
I thihk this is the first failure I have had on this printer
Oh and my very fist Rapido where a wire pad came off the ceramic heat block...probably due to user heavy handedness.
That temp graph looks very much like a broken thermistor wire. I've found it easiest to diagnose them by heating up to >250 on the rapido and using something temp insulated to push the wire for the thermistor around and see if you can reproduce it. The higher the temp, the easier it is to diagnose the broken thermistor, and as they progressively get worse/break more, the issue shows up at lower and lower temps.
The other less common failure I've seen with that is the wires for the heater cartridge on the rapido. I had that happen to me (see photo) and it was still in the connector, just lose. As the toolhead would move around it would intermittently connect, rapidly spike up in temp causing the software to cut power suddenly, start dropping in temp, but then it had already lost contact again and couldn't heat up. Ended up in wild temp swings.
At high speeds, I've found the rapido wires to not be very reliable. Multiple zip ties, keeping the wires tight (without breaking them while installing them), and using a toolboard has reduced failure of the wires for me to zero, but there was a stretch where speed benchies were killing my wires for the rapido.
Simulating both broken thermister wires and broken heater wires by unplugging the connectors one at a time.
I notice that if I unplug the thermister wires the temp immediately drops to zero as does the power to the the heater chart. This is not what I oserved in the Mainsail chart.
I notice that if I umplug the heater wires the temp gradually drops and the power in the heater chart ramps up, which is what I observe in the chart.
So I suspect my issue is the heater wires.
The are firmly attached to the ceramic, so issue is probably in connector at the print head or the wiring in the umbilical cord or the connection to the MCU....
All the connectors at the print head look good, all wires crimped firmly and heater wires firmly screwed in on the MCU. NO amount of jiggling of the wires anywhere has reproduced the issue.....I may need to wait until this becomes less intermittent....
Its possible that the heater wire plug at the print head was not fully seated....but I think that might just be hopeful thinking...
You can also use a multimeter to test to see if the wiring is bad, do the same thing you are doing with heating it but instead use a meter and check for breaks in continuity. PID may also help is the temp is not getting to steady state quickly
@Dom Dell Computer another couple of good suggestions thanks. I did a PID earlier but it didn't change anything . Unfortunately this failure is intermittent jiggleing all the connectors and wiring while testing has pin pointed the problem yet, Next print is nearly finished (touch wood) and no failure this time, but I have no confidence that the problem won't show up again shortly.
Did you upgrade to 2.1 and are you running an EB42 with PT1000? If so you may need to put in a jumper on the EBB42 because of the pull up resistor.
No and no and no.
I had some random issues with my minion with that error. Not having broken or loosen wires. It was a fan issue blowing on closed holes of the infill and air was going up to the hotend nose. I guess the airflow was messing with the rapido heating capacity.
I tryed to run a new PID with fan on and with hot end on a low position and it solved the problem on the same print, I managed to end it.
I’m using a pretty powerful 4028 at 20% fan speed (that’s the minimum)