1 Topic by perlguy

  • perlguy
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Topic: Tweaking Tips Needed

So I've got my extruder and flow calibrated, and I think that they are almost perfect.

However, I think I am stuck on getting retraction tweaked.  I've done about 40 test prints of the 40x10.stl file, and I still end up with plastic dingleberries all over my print.

As you can see in my photo, I seem to have nice, strong edges, but in other places, I have plastic loops sticking out.

I am printing at 180C and my retraction settings are:

Length: 1.25mm
Lift Z: 0
Speed: 300mm/s
Extra length on restart: 0.6mm
Min travel after retraction: 0.5mm


With all of my test prints, if I would change these settings too much, I would end up with more of a blob than the test print.  These are the settings that "seemed" to do best, but not perfect.

What are the best ways to get rid of these dingleberries?

Thanks!

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2 Reply by nickythegreek

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Re: Tweaking Tips Needed

I believe that the speed should be set to 75 and that extra length on restart seems super high.

I am not at the house, but I think I use these settings with my Octave filament:
Length: 1.15mm
Lift Z: 0
Speed: 75mm/s
Extra length on restart: .03mm
Min travel after retraction: 0.5mm

3 Reply by cmetzel

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Re: Tweaking Tips Needed

My retraction settings in Skeinforge are:

Extruder retraction speed (mm/s): 10.0
Retraction Distance: 0.6
Restart Extra Distance: 0.05

4 Reply by perlguy

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Re: Tweaking Tips Needed

Wow, pretty big difference between both of your settings.

I am still tweaking, but still seeing lots of extra dingleberries.

I'm not giving up yet!

5 Reply by cmetzel

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Re: Tweaking Tips Needed

Mine are the default that shipped with the printer, I have an early model.  I have never needed to tweak them and mine are dingleberry free.

6 Reply by IanJohnson

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Re: Tweaking Tips Needed

The standard I have heard is as fast as possible, and as low a distance as you can get away with.  Extra length after restart is there to give the filament a head start if it doesn't seem to be all of the way back to the nozzle by the time extrusion starts again.  Use this if you are getting little gaps after the retractions.  Having this active when you don't need it causes blobbing because you are adding extra plastic.  With such a high retraction speed, you should probably have Extra Length set to 0.

Are you getting those blobs when the nozzle leaves the perimeter, or when it comes back?  If the blob is from ooze on the nozzle wiping off when it comes back then the problem is Extra Length on Restart.  You might also turn up the travel speed so there is less time for it to ooze.

When there is ooze when leaving the perimeter, it usually turns into strings or thin hairs.  Little loops are more likely blobs getting wiped onto the print, so I would bet that you need to set extra length on restart to 0.  If that causes little gaps, lower your retraction distance so it doesn't have as far to go to start extruding again.

7 Reply by jawhn

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Re: Tweaking Tips Needed

Sorry for bumping an old topic, but this thread addresses my concern, so...

None of these replies suggest to mess with the "Lift Z." ... Why not? Seems like that would be a really good thing to have it do, no?

I get lots of "smearing" from head travel along surfaces already printed. It's very frustrating.

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8 Reply by IronMan

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Re: Tweaking Tips Needed

If you are still getting the smearing, then try the Lift Z...I tried it some months back after I saw a Stratasys in action and have been using it since...Not at my machine now, but I think it was Lift Z at .5

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9 Reply by IanJohnson

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Re: Tweaking Tips Needed

Smearing is most likely from over extrusion,  so try reducing the extrusion  multiplier.   Z lift is good for not knocking over tall thin objects,  but if there is backlash in Z it might cause problems with not returning to exactly the right height each time.

10 Reply by IronMan

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Re: Tweaking Tips Needed

IanJohnson wrote:

Smearing is most likely from over extrusion,  so try reducing the extrusion  multiplier.   Z lift is good for not knocking over tall thin objects,  but if there is backlash in Z it might cause problems with not returning to exactly the right height each time.

+1...I never had much of a backlash issue for some reason and I keep an eye on the extrusion multiplier vs filament diameter...but beyond that Z Lift did improve my overall print quality for some reason...

SD2 - Stock - Enclosure - Heated Bed - Glass Plate - Auto Fire Extinguisher
Ord Bot Hadron - RAMPS 1.4 - Bulldog XL - E3D v6 - 10" x 10" PCB Heated Build w/SSR - Glass Plate
Thanks for All of Your Help!