K values with new hotend

Other topics
1

I just replaced the 0.4mm hardened steel hotend on my X1C with 2062 hours.
I preformed the automatic Flow Dynamics calibration on the 3 PETG spools loaded in my AMS. I was surprised at how much the K values changed:

Filament Old New
BBL PETG White 0.048 0.035
BBL PETG Red 0.048 0.032
BBL PETG Black 0.056 0.041

Is this much of a change normal?
I don’t have any notes regarding my PETG K values when the prior hotend was new, so I do not know if it slowly increased over time or something else.

2

That would be really interesting to find out. If anyone can share some useful infos on this, I’d appreciate it as well.

3

If the new values produce good prints, it does not matter what worked for the old nozzle, which was probably worn and possibly partially clogged.

I think you may also have dropped some zeroes, my PETG K values are more like 0.040.

5

Indeed I did (drop a zero). I have now edited it. Thanks.

6

When a hot end is older the hole tends to be bigger and have more imperfections, which will affect the K value

7

At 2500hrs, i guess i should change my nozzle also. :flushed: