This time I’m asking for some assistance. I have “problems” interpreting my results from some retraction tests. My printing profile (S3D) is pretty much the work of some years of printing experience without printing fancy test prints. But since I only print with PETG and have constant stringing I printed some retraction tests.
E-steps, K-value and temperature are very good calibrated.
Now I have the problem that there are no diferences between the test prints.
They are all looking the same for me! Here the pictures I’m talking about:
Constant speed (40 mm/s), retraction distance 1,0…1,8 mm (increments of 0,2 mm):
The gcode files were created with Simplify3D using 5 processes for each print with the variating settings. As long as this way works (and I’m pretty sure since I’ve used this feature for dozens of times) the gcode files are good (temperature test files are easier to evaluate with some searching inside the gcode).
I can’t and won’t decrease the temperature further because of layer adhesion problems (structural integrity) below 220°C. To be honest, I know that I can’t completely eliminate stringing with PETG but is this really the best I can do with my setup?
You can see different filaments in the pictures. The gray one is about 1 month old, the clear one about 1,5 years. Ambient temperature is pretty constantly 25°C, humidity about 45-50%.
The 40 mm/s is not the printing but the retraction speed (but as far as I understand the configuration on the controller the max. speed for the extruder is reduced to 25 mm/s).
Normally my print speed is between 40 and 50 mm/s.
Layer height is 0,20 mm.
Z-hop enabled to 0,80 mm.
Temperature, extruder and linear advance are tuned fine as I wrote.
My material says to be printed at 210-230°C so I’ve tested these temperatures. Of course less stringing at 210°C but layer adhesion is not good enough. 220°C is the middle and creates the best results overall.
But can anybody tell me why there are no differences with changing settings?
Wiping and coasting are 2 things that brought more problems for me than solving them.
When you want to eliminate 1 small problem (stringing) and have so many options to fiddle around you have at least to understand why there are no changes in the output.
At the moment my result is that retraction speed and distance don’t make a difference…and I don’t understand why.
If its not wet filament, there is a chance your temperature is not on point.
I recently saw that the new value of pid is far off and makes the heating sluggish.
Even a bit thermal paste to the thermistor could help.
