Duet2WiFi E0 Failing

k3lag

I think I may have E0 failing on my Duet2Wifi. After working fine since I built the printer last fall, I had a heater failure last night when the temperature dropped too low. I cleared the fault, activated the heater and it came back up to temperature but as soon as I restarted the print the temperature started falling again. If I disabled the fan and drastically reduced the print speed the heater would keep up for a while but eventually the temperature would drop and it would fault again.

This morning I moved the heater wires to E1 and started the same print and so far it seems fine.

The heater is an E3D 24v 40w premium heater and it's resistance measures 15 Ohms so I think the heater is fine.

Once this print is finished I'll move the wires back to E0 and try again but everything was tight when I checked.

Larry

Phaedrux

Have you done a PID tuning?

k3lag

I'm pretty sure I did one when I built the printer but just to be sure I did it again last night. Here are the results.

M307 h1
Heater 1 model: gain 630.3, time constant 265.8, dead time 5.3, max PWM 1.00, calibration voltage 24.5, mode PID
Computed PID parameters for setpoint change: P14.2, I0.378, D52.7
Computed PID parameters for load change: P14.2, I0.883, D52.7

Phaedrux

And have you saved those results with M500 or transferred them into config.g?

For best results you should have the part cooling fan on a normal operating speed during the tuning so that when the fan comes on it doesn't drop the temp so unexpectedly. A silicone sock on the block also helps greatly.

k3lag

@Phaedrux I have a silicone sock on the block and I have been printing successfully for months. This problem happened suddenly last night.

Phaedrux

Just trying to run down the usual suspects before we conclude hardware failure.

k3lag

@Phaedrux I understand. I'm curious to see if it goes back to failing when I switch back from the E1 to E0 heater after this print. Still about 2 hours to go to finish this print.

Phaedrux

If you do get another drop, please take a screenshot of the temp graph as that can tell a lot about the nature of the problem. Also the exact error message produced. And the results of an M122 never hurts.

k3lag

@Phaedrux I will. Typically it drops from the set point, 210c, to 195c over about a minute. Then of course it faults. If I notice the temp dropping I can pause the print and the temp will come back up. Then when I restart the print it will print for a short while and the temp will start dropping again. When I was messing with this last night I could get it run for about 20 minutes if I dropped the speed to 20mm/s and turned the fans off. Right now it's printing fine at 100mm/s with the fan on using the E1 heater connection.

k3lag

I've switched back to the E0 heater output and everything seems fine. Even though all the connections seemed good it must have just been a loose connection or something. If it comes back I'll let you guys know but for now consider this closed.