I’m experiencing a strange behavior I can’t explain with my hot-end.
I’m printing ABS at about 230°C. Every 20 minutes or so the temperature is dropping to 215-210° during 4 minutes and then back to 230° for another 20’.
There’s no bad connection or anything like that. And I’m not using the stock power supply. And there’s a fan cooling the board.
Could it be that the control circuit is overheating and some fail-safe mechanism is kicking in?
Is there some air blowing on the printer.
Maybe A/C or heater turning on?
[quote=“Wrong Way”]Is there some air blowing on the printer.
Maybe A/C or heater turning on?[/quote]
Nope the room temperature is steady and about 20°C
It was just a guess
Sorry
Hi raby,
during the low-temperature time, the heater seems to be fully on. Do you also see this on the board, i.e. does the HEATER1 LED light up constantly?
If that is the case, it would rather not be a failsafe mechanism, but point to the temperature measurement.
Cheers,
kuraasu
The heater LED is on.
And the temperature is really dropping as the ABS become sluggish, barely fluid enough to (badly) print something.
I was thinking of something limiting the current as the drop is always the same and the temperature stays at the same level during 3-4 minutes. And the drop occurs regularly after 18 -20 minutes.
… which the board can only do by PWM-ing the output, so you would have seen.
Can you monitor the current (or voltage and current) applied to the hotend?
Does it only happen during printing (i.e. when the motors are moving and the heatbed is also on), or also when only the hotend is active?
Ok my bad and stupid me.
I’ve found the origin of this behavior. I’m printing with ABS and had auto cooling on at 25% and only for small areas. And also 100% for bridges.
I’m inserting a solid layer every 5 layers and obviously Slic3r is considering this solid layer is a bridge and the fan kicks in at 100% explaining the temperature drop… The fan only switches off automatically after 3 or four layers.