K8400 extruder temp going up and down

Vertex 3D Printer Vertex - Issues while printing
1

Hu Guy’s,

I have a K8400 for 2 weeks.
These two problems started both this weekend:

1: sometimes no connection with the printer, then when i reinstall the firmware i can connect back with the printer.

2: the temp of the extruder is going op and down (what i not had before) result bad printing

I joined a picture of the temp curve
Can somebody help me out please.
Thanks Pascal


https://www.dropbox.com/s/7czpohz6hhi8d54/K8400%20Temp.JPG?dl=0

2

When you reloaded the firmware did you use the Arduino software 1.0.6 or below?
Check the wires going to the heater for the nozzle, Make sure they are tight.

3

Hello,

Thank you for your reply :wink:
I use the 1.0.6, with the latest firmware. I will cheque later today is the wiring is tight enough.

Thanks
Pascal

4

I have seen on your picture that you have enabled active cooling. What does it mean for your slicer? Is the fan constantly on or does it vary during printing? For the unmodified K8400 hot-end this is a major issue for thermal stability.

I would recommend to print using a constant air flow by the fan, it must not be necessarily at 100%.

5

Hello Problem solved,

Thanks

6

[quote=“Pascal Deneef”]Hello Problem solved,

Thanks[/quote]

How did you solve it? Maybe I can learn about it?

thx

bstrgds
Maexchen

7

I am having a similar problem where the temperature of my extruder is fluctuating wildly between refreshes of the LCD panel. It is meant to be printing at 190°C, but it sits around 180°C and sometimes drops down to as low as 160°C. I highly doubt it is actually fluctuating this much, so I imagine it is an issue with the connectivity of the thermistor, but how would I go about checking this?

Thank you!

8

Disconnect the thermistor from the green connectors.
Check the resistance at the wires of the thermistor.
at room temp you should see around 100K ohms.
Check the wires for the heater at the green connectors make sure that are tight.
Check the plug that goes to the print head (in the back) make sure it is seated tight.
You should check the connector on the control board for heater 1 make sure it’s tight as well.