XT-CF20 settings help...

[rich080487 0]

Hi,

 

I have a UM2+ with a Bondtech extruder (recently fitted) and a ruby nozzle.

I have been experimenting with ColorFabb XT-CF20 over the past few days. I have been struggling with getting my settings spot on...

I first used the average settings suggested by colorfabb (250degC, 65degC bed, 50% fan, 55mm/s print speed, plus other standard settings).

My first print created lots of stringing, so I designed a basic part to test for stringing and tried again...

 

 

To counteract this I tried reducing the temp to 240degC and increasing retraction length to 10mm. This definitely helped, but it still isn't perfect (especially at the top of the prints).

 

I have tried a number of prints varying print temp and retraction length to try and reduce the stringing. I still can't get a perfect result.

My second print is the best one, but there is still a very small string at the top of the print and looks like it might be starting to under extrude.

 

 

I am going to set off another print, but at a slower speed to see if that helps. Does anybody else have any further suggestions?

 

TIA,

Rich

 

P.S. The nozzle also gets caked very easily. Any ideas? (hoping this is unrelated)

 

 

[rich080487 0]

Any ideas? Or does anyone need more information to help?

 

Thanks, Rich

[rich080487 0]

Have I posted this in the wrong section? I am surprised no one has any advice...

[Catlord 17]

HiHi,
i have opened a french discussion with my parameters here : 

 

Here's my parameters :

- UMO+ V2 ( means it has the same motherboard as you)

- E3DV6 + hardened steel nozle

 

=> custom firmware to reach 280°C

=> PID autotune done at 280°C

=> extruder calibration done

 

cube single shell and temperature Tower printed

results :

 

- flow rate 80%

- 280°C printing

- retractation 6.5mm

- print speed 20mm/min (need to be tested at 40mm/min to reduce print time)

- layer height 0.2mm

 

There are photos of my temp tower in the other post

Edited July 10, 2019 by Catlord

[johnse 31]

Hi @rich080487,

those aren’t strings, they are “antennae”.  Whereas strings are material sticking to the just-printed object as the head travels to the next, these are formed as the head completes travel to the new part. A small drop is hanging from the nozzle and attaches to the outside of the prior layer. Next layer, the drop hits that previous drop, and so on. This is why they grow up and away from the part.

 

Temperature doesn’t affect these much. I think retraction may be the thing to focus on.