Printing red XT - how to improve

[axsdenied 0]

I finally got hold of some red Colorfabb XT, hopefully to avoid using ABS when printing some large and tough enclosures. I managed to improve the quality quite a bit but I am stuck with several problems. Any hints would be greatly appreciated.

1. Stringing:

There is leftover plastic on the sides where the head retracts and does a "jump" to the other side. See bottom of the image.

Combing was off.

Retraction was set to 40m/s, length = 4.5mm as per Colorfabb's guide here.

Travel speed was 200 mm/s which helped remove stringing a bit. I even tried 250 mm/s but it did not improve things.

Temperature 245 and 240 degrees (not much difference).

I also tried without fan and with fan at 30% (I am using dual fan mount), again I did not notice any difference.

XT is not supposed to need much fan?

I am not sure what else to try...

2. Infill

The infill looks very bad at places, big sections are missing. I don't think there was underextrusion (no stepper clicking) and the outer layers look fine. The infill was printed at the same speed as the outer layers. Fill density was 25%.

Any thoughts what happened?

Settings:

Layer height 0.2

Shell thickness 2.0 (for extra strength)

Bottom/top fills 2 (for extra strength)

Fill density 25%

Print speed 50mm/s (also tried 30mm/s for the outer shell)

Travel speed 200 and 250

Fan off and on

Temperature 240 & 245 degrees, bed at 70 degrees.

Flow 100% and 105%, it did not seem to make a difference for the infill but 100% helped a bit with the point 1.

Retraction speed 40 mm/s, length = 4.5 mm

 

 

[Dim3nsioneer 557]

I had my issues too with red XT. I think the only recipes are: hotter or slower. Fan is needed but only about half.

 

[axsdenied 0]

Will try hotter and slower and report.

At what height would you start the fan?

[Dim3nsioneer 557]

So far I had it on at the second layer but maybe it's better a bit higher up. You will have to try...

[axsdenied 0]

Ok, here is the best I could come up with. Not much red XT left to play with :smile:

The results are quite good. I am using simplify3D.

• layer height: 0.2mm
  
• speed: 40mm/s
  
• extrusion multiplier 1.1
  
• 100% fill
  
• first layer speed: 66%
  
• outline underspeed 50%
  
• solid infill underspeed 80%
  
• temperature: layer 1 = 240C, layer 2 = 245C, layer 3 = 250C.
  
• glass plate at 75C (I measured the temperature of the glass plate with a thermocouple and it was roughly about 5C less than set on the printer). That 5 degrees made a huge difference.
  
• fan: layer 3 10%, layer 6 30%, layer 9 40% (note that I am using https://www.youmagine.com/designs/ultimaker-2-fan-mount-dual--2 fan mount)
  
• retraction: 5mm @ 40mm/s
  
• x/y axis movement 250mm/s
  

 

[hreedijk 4]

Those settings would be my advise also, except for the first layer speed.

40mm/s is my start at 244 degrees with XT red.

 

[alain13260 1]

With my UM2,for red XT, 50% fans and no hotter than 230 to 235° & speed 40 mm/s works well.

Edited April 22, 2015 by Guest