Very slow support print speed around object

[Adam324 13]

I am printing a pen that I am trying to design.  I need support around it so that it doesn't fall over when printing.  When I add the support, the generated preview and actual print speed of the nozzle movement is VERY slow when printing the support around the object.  It is to the point that filament leaks out of the print head causing underextrusion.  If I reduce the nozzle temp, the filament will not print well so I can't compensate by lowering the temp.  If I print the object without support, or other objects where I don't use support like this, I don't get underextrusion with the same filament.

 

I suspect the wall design is somehow causing the support gcode around the object to be way to precise causing an extreme slowdown or something but I really don't know.  Anyone have any idea why support gcode would be so slow around this object?

 

I zipped up the saved project in Cura and also the .stl file and attached it to this thread.

 

 

WD9_Body18.zip

Edited March 26, 2020 by Adam324

[burtoogle 516]

Please do File -> Save and attach the .3mf file to this thread. Thanks.

[Adam324 13]

Oops.  I forgot to include that in the .zip.  Here it is.

WD9_Body18.3mf

[burtoogle 516]

Thanks for the project file. My guess is that the slowdown is caused by the very large number of line segments in the curved area of your support object. Not sure if that can be altered using the Cura settings, it could be a slicer problem that needs fixing.

[Adam324 13]

Thanks for the input.

 

I removed the fillet from the corners and made the pen solid all the way through just to make the object simpler and the support around it still comes to a crawl next to the object.  It must not be the detailed fillet.  I went back to 4.3 cura and it has the same behavior.  Maybe something about the twisting walls not being sliced well?

Edited March 26, 2020 by Adam324

[burtoogle 516]

Hi, I have sliced your project after doing a mod to Cura, can you please print at least a part of this to see if the slowdown has gone away? Thanks.

 

WD9_Body18.gcode

[burtoogle 516]

Hello again, please try this gcode instead of the last. Thanks.

 

WD9_Body18.gcode

 

This gcode is almost 50% smaller than the gcode you were getting before. It should print faster!

[Adam324 13]

Very fast.  It is working great!  Night and day difference.  Nice job.  The support was missing a lot of sections before and now it is all 100% solid.  I was also getting zits or blobs and it looks like that is gone now too (40% printed so far).

 

It appears you didn't have the zoffset plugin installed so I had to adjust the z like the plug does but it printed great after that.  Very easily done though.  I wouldn't have expected you to know that :). 

 

G0 F3600 X144.966 Y143.593 Z0.82 ; manually adjusted z offset like the zoffset plugin
G92 Z0.2 ;consider this the original z before offset

 

Edited March 27, 2020 by Adam324

[burtoogle 516]

Great, thanks for the feedback. I will submit the mod to the Cura devs so that it can be in future releases. In the meantime, my next Cura build will contain the mod. I expect I will do a build over the weekend. You can find my builds at https://www.dropbox.com/sh/s43vqzmi4d2bqe2/AAADdYdSu9iwcKa0Knqgurm4a?dl=0

 

Please read the README.md file there for more info.

[Adam324 13]

Thanks!  I look forward to using a build with the mod.

[Adam324 13]

EDIT: Disregard this post.  Burtoogle figured this out for me too.  This issue was related to having 'limit support retractions' turned on and not a problem with the mod.  The mod works great!  Limit support retractions does not appear to retract when going through an object wall.

 

Well...  After trying to remove the support, It looks like it stuck to the object pretty good in 1 or 2 areas where the old VERY slow version didn't.  Those lines are stuck really good to the part.

 

EDIT: FYI... I broke it right above the support area so it is shorter than it normally would be.  This is the bottom section.

 

Edited March 28, 2020 by Adam324

[Adam324 13]

Does the Cura preview in your build show it close in that area?

EDIT: I am going to print it again at lower temps.  It never stuck like that before but I know that this filament is pretty oozy as I get some stringing in the support area because I have needed it a little hotter to print right (Makergeeks Dragons Metallic PLA).  Maybe with this mod, it is just a little closer with this new mod or maybe it is taking a new path that it didn't before.  Looking at it with pronterface, I think that is where there is a travel move from support to the wall on the other side.

I am also going to print the original gcode file again.

Edited March 28, 2020 by Adam324

[Adam324 13]

I printed with your moded Cura gcode again with lower temp settings (almost to where it is starting to have layer issues) and I think there must be some setting missing or something else causing this new behavior where travel moves to the object are somehow extruding filament where it isn't with my Cura.  I am thinking it is not related to the speed fix that you did.  I will hopefully be able to verify that when I get your build of Cura.  I have never seen this kind of behavior before.  The support looks plenty far away from the object to be causing it to stick to the object.  I have a feeling your mod is fine unless it is somehow causing a problem with another area of Cura/feature.

 

I broke the top off the pen so that we can see directly down into the support area with the pic below.

Edited March 28, 2020 by Adam324

[burtoogle 516]

I think it's because you have limit support retractions enabled, compare these two images...

 

With limit support retractions enabled...

 

 

Without...

 

[burtoogle 516]

Here's the gcode with the limit support retractions turned off..

 

WD9_Body18.gcode

 

I will build a release today.

[Adam324 13]

I think that is it!  I guess your gcode just goes a different direction and is a lot more noticeable.  I have never played with that setting (was still hidden) so the profile I started using must have had it enabled or it just defaults to enabled.

 

I wonder if that is a bug that 'Limit Support retractions' does not retract when going through the printed object walls?  I would think that would only apply if it were going from support to support but only if it did not traverse the object.  I am obviously wrong though :).  I will disable that on my Cura as I never want it to not retract when going over the object.  I think it is just showing up a lot more with this not so good filament I am using that oozes a lot more than any other I have had but requires high temps to keep it from having empty spots from not extruding.

 

I am printing your newer gcode now.

 

EDIT:  I see that there are still some lines going directly to the object with Cura 4.5.0, there are just not as many so this setting is the problem.

Edited March 28, 2020 by Adam324

[Adam324 13]

Your latest gcode with 'limit support retractions turned off' worked great.  The issue was not related to the mod you did as I suspected(and you likely knew 🙂).  The best print I have had.  I will be keeping that setting off until I find a way for it to not do that when it goes through the object's walls.  You have likely solved other issues I have had in the past with support sticking too well when using support like this.  Thanks!

 

The 'limit support retractions turned off' might actually work too well for some prints as it doesn't have any lines going to the print to keep it still.  The print can move easier now inside the support as the support really isn't touching it.  If I ever need it to be closer though I can just adjust the settings to bring the support closer.

Looking forward to the build with the mod to fix the slowdown.  Thanks.

Edited March 28, 2020 by Adam324

[burtoogle 516]

Hi, I have built for Linux and Windows 64 bit, will do the MacOS release tomorrow.

[Adam324 13]

Do you know if the work you put into this will eventually be integrated into mainline Cura?  I think I recall there was a pull request created for it.  Do you know if that went anywhere in the official Cura circles?  This makes a HUGE difference in eliminating slowdown while printing support up close to the object.  This is just a regular object that needs support and not like the previous example where I was trying to keep the object from tipping over.  I tested 4.6.1 official release and it is still having issues with slowdown with support around objects.

 

I have included the project for 4.6.1 that was used to print it.  The speed difference when printing the support when close to the object with your build doesn't slow down at all and makes a big difference with underextrusion when it moves to the next area.

 

 

WD9_FanLightDiffuser_BaseV9Beta.3mf FanLightDiffuser_BaseV9Beta.stl

Edited May 23, 2020 by Adam324