Smoothieboard looses extruder set ? Smoke on the printer...

smoothie-forum
(pbisiac_SW) #1

Hi,

My smoothieboard often stops regulating hot end temperature while printing.

A few minutes ago, during a print, my hot end started to produce white smoke (I am printing in ABS). I immediately checked temperature with a thermometer……270°C and rising….very strange…

I immediately sent a new setpoint with pronterface and temperature lowered. It 'seems like smoothie board has loosed it’s set point (or taken another one). but I don’t have any M104 or M109 codes in the middle of my file.

This inconvenience happens quite often (3 times in 6 prints). Pleas note that printing goes on properly (X-Y-Z-E). I did not check my heated plate due to panic.

This problem is quite serious, in my opinion. I don’t think this has something to do with probes hardware: when I send a new Gcode (M104 S225) temperature starts immediately to reduce and goes to right values. I enclose some readouts from my extruder, there are some strange oscillations (240 to 169 °C in few seconds ??)

SENT: M105
RECV: ok T:246.4 /225.0 @0 B:79.6 /80.0 @5
SENT: M105
RECV: ok T:244.5 /225.0 @0 B:79.6 /80.0 @188
SENT: M105
RECV: ok T:240.1 /225.0 @0 B:79.7 /80.0 @188
SENT: M105
RECV: ok T:207.6 /225.0 @64 B:79.6 /80.0 @189
SENT: M105
RECV: ok T:245.2 /225.0 @0 B:79.7 /80.0 @189
SENT: M105
RECV: ok T:201.9 /225.0 @64 B:79.7 /80.0 @189
SENT: M105
RECV: ok T:229.5 /225.0 @0 B:79.7 /80.0 @189
SENT: M105
RECV: ok T:198.8 /225.0 @0 B:79.7 /80.0 @189
SENT: M105
RECV: ok T:169.8 /225.0 @0 B:79.7 /80.0 @189
SENT: M105
RECV: ok T:206.0 /225.0 @64 B:79.7 /80.0 @190
SENT: M105
RECV: ok T:204.7 /225.0 @64 B:79.8 /80.0 @189
SENT: M105
RECV: ok T:241.2 /225.0 @0 B:79.8 /80.0 @189
SENT: M105
RECV: ok T:238.7 /225.0 @0 B:79.8 /80.0 @189
SENT: M105
RECV: ok T:233.3 /225.0 @0 B:79.9 /80.0 @189
SENT: M105
RECV: ok T:232.7 /225.0 @0 B:79.9 /80.0 @189
SENT: M105
RECV: ok T:231.5 /225.0 @0 B:79.9 /80.0 @189
SENT: M105
RECV: ok T:229.8 /225.0 @0 B:79.9 /80.0 @189
SENT: M105
RECV: ok T:227.8 /225.0 @0 B:79.9 /80.0 @189
SENT: M105
RECV: ok T:224.7 /225.0 @26 B:79.9 /80.0 @189
SENT: M105
RECV: ok T:221.5 /225.0 @64 B:79.9 /80.0 @189
SENT: M105
RECV: ok T:228.1 /225.0 @0 B:80.0 /80.0 @188
SENT: M105
RECV: ok T:227.0 /225.0 @0 B:80.0 /80.0 @188
SENT: M105
RECV: ok T:224.4 /225.0 @64 B:80.0 /80.0 @188

Any ideas ? Perhaps a PID runaway ?
Thanks

Imported from wikidot

(Arthur Wolf) #2

This sounds -a lot- like a connection problem with the thermistor, or a problem with the contact between the therimstor and the hotend.

I’d make absolutely sure there is no problem there, before investigating anything else.