Underextrusion due to over retraction?

[Qdeathstar]

Hello, working to get my printer fully calibrated and have rant into another issue.


It seems like I am having issues with underextrusion when printing "ridges" or small areas in between large gaps. I'm thinking this could be due to the filament being retracted in between the ridges and when it moves over to the next ridge, it extrudes air for a bit causing the under extrusion?

I checked my retraction settings which haven't been changed from the defaults and it is at 6.37mm, which seems like wayy to much, from what I remember on my prussa...

Obviously this is "why not test it" theory but unfortunately I had to go and go on vacation and won't be able to play for another four whole days

If there are any alternate theories I'm listening as well

Here is picture where there is not a lot of retraction going on, then another picture where there is ten tons of retraction (it seems to get worse as the space between ridges increases)

[Mac The Knife]

The retraction length for your Prusa would be shorter because of the shorter distance between the hot end and the extruder. The longer the path, the more the filament compresses in the bowden tube, the more retraction length needed to relieve the pressure on the hot end.

[Qdeathstar]

But, do you think the longer Bowden tube would require extra push to get started again after the retraction? Right now it is set to .1mm extra after retraction... Perhaps I should increase that to .2-.3 and leave the retract at 6mm?

[abecker]

Hey Qdeathstar, I would be interested to hear what you find. Here is another post on a similar topic http://forum.seemecnc.com/viewtopic.php?f=37&t=10582

[Qdeathstar]

Yes, I saw your topic.... But you don't seem to be printing in an area with a lot of retractions...

It could be a partially clogged hot end, because at the same time, these areas are also printing slower because they are smaller.... Slower = less filament being pushed = wammo So I am going to try to clean the extruder. I only got .4mm drill bits so they'll have to do

[Qdeathstar]

So,

I stuck a .5mm drill bit into my nozzle, reduced retraction speed to 60mm/s, increased extra extrusion on retraction from .01mm to .03mm and reduced the extruders acceleration from 5500 to 3000 and those things combined turned my under-extrusion issue into a bit of an over-extrusion issue. I had decreased the filament diameter to 1.7 trying to figure out the extrusion issues so i think when i bump that up to 1.73 (measured) i will get better results.

[Qdeathstar]

Here is an aftershot:

[Sonrisa3D]

This guide can help in dialing in retraction.
https://www.matterhackers.com/articles/ ... -to-oozing