Hot end heater issues and tuning. . .

[longshot]

Duet Wifi running 1.15 firmware
Rostock Max V1 with E3D Cyclops hot end
850Watt High quality (OCZ) converted CPU power supply
2 Greg Wade type extruders (bowden setup)
Printing ABS at 250C, no layer fan.

Having issues with my hot end. At first i thought it was a tuning issue.

I have to run M303 H1 P0.7 S260 to hit max temp of 259C
I am able to run the same command and get similar results
I then put those numbers in my config.g with the M307

The problem i'm having is I can reach 240-250 with no issues. Its very stable with no ocillations in the graph. I can leave it like this for sometime with little deviation. I can bed calibrate with this and no issues.

However when I start to print about the 1-2 layer or so I occasionally get a high temp excursion. Its more frequent the higher the temp i go.

Not sure whats going on. Thoughts?

[dc42]

How large is the temperature excursion? Can you post a screenshot of the temperature graph from DWC?