Really bad print results. Pls help

[Torgeir 242]

It's easy to press a key - sometimes...

 

Way to go Greg..

 

 

[GregValiant 1,251]

@Zarkhowler - I just noticed an error in my last post.  You want to insure that the EXTRUDER will move at 45 - the Z doesn't matter so much.  So those lines I suggested should be:

M203 E45

M500

BTW the max you can move the Z is usually around 45 (or the lead screw can chatter) so no harm if you put it in as I originally posted.

[Zarkhowler 0]

So I tried printing at 195 deg and 5 mm retraction and 40 mm per sec speed. The dog still came out really stringy even though the temp tower and retract tower were ok at those settings. 

Edited October 9, 2021 by Zarkhowler

[GregValiant 1,251]

Within the Travel settings is "Retraction Minimum Travel" and "Max Comb Distance with No Retract".  If either is set too high then there isn't any retraction.  Set them to something low (like 2mm).  For some parts that will be too little but for the dog and the stringing between the model and the muzzle-support it should limit the stringing.  When you look at your model in the Cura preview you need to turn on the Travel lines to eyeball some of the distances and then make settings adjustments to insure you get retractions when they are needed (like moving from the neck to the muzzle-support).

 

With my printer I don't use "Retract at Layer Change" and "Retract before Outer Wall" as they tend to leave marks.  Z-Hops can also either cause or cure some stringing.  Since the muzzle-support is the first thing to print on a layer then maybe you want "Retract at Layer Change" enabled.

 

My experience (so far) is that large models with infrequent retractions are easier to tune than small models where retractions occur pretty much constantly.  I found that "Connect Infill Lines" and "Connect Support Lines" can also help to limit the number of retractions.  If the machine is constantly pulling molten plastic back into the hot end it's only a matter of time before a partial blockage occurs.

 

Edited October 9, 2021 by GregValiant

[Zarkhowler 0]

Printed at .2 layer heights. With 6mm retractions and made the minimum retraction distance .2 mm. With 25mm per sec retraction speed. It's an improvement so Im thinking about 8 mm retractions. Also a wierd gap of no filament.

Edited October 9, 2021 by Zarkhowler

[Zarkhowler 0]

Also I did 10 mm retractions and it worked for the most part but the z Sean for the support was pretty wispy. Any ideas?

[GregValiant 1,251]

At 10mm you will be pulling molten plastic into the bowden tube.  That is a "bad thing" as the plastic will harden and cause a restriction in the filament path.  After a while it will get critical and there will be extrusion problems as the filament finds it harder and harder to push through th restriction.

 

If by "wispy" you mean the cotton candy looking floss - I've never been able to cure it.  I have found that some nozzles are worse than others so it might be mechanical.  If the nozzle isn't exactly straight up and down then the bottom isn't exactly flat and that might have something to do with it.  When I print with white PLA I noticed that my layer cooling blower (a robust 5051 blower) really has an effect and blows the wispy strands all over the place.  With black or red PLA the problem doesn't happen and that indicates it might be dependant on whatever the filament manufacturer decided to use for color.

[Zarkhowler 0]

So after tussling with this problem for a while, I found a solution to my problem. The extruder ptfe tube was slightly shifting in the extruder coupler which meant print in accuracies. I printed a coupler reinforcer which completely solved the problem. Now I get only a little bit of stringing and everything is great. Thanks everyone for your help

[Zarkhowler 0]

Yeah so I'm back. If you zoom into the pic then you can see a little bit of underextrusion right after the seam. Any ideas as to what might be causing the problem