Trouble printing with Willowflex on UM2+

[PrintingPal 0]

Hello!

 

I am struggling to get a consistent quality of prints in Willowflex on my UM2+. Each print (below) has been printed with the same settings, which generally follow the Willowflex recommendations but some prints work and others don't. I am hoping someone can help diagnose the problem?

 

Print 1: printed at 6pm

 

Print 2: printed approx half an hour later around 6.30pm

 

Print 3: printed the following morning around 9.30am

 

Print 4: printed approx 2.5hrs later at 12pm - similar result to print 2

Print 5: printed straight after at around 12.30pm - again similar result to print 2

 

Does anyone have any idea what might be causing the problem?

 

Thanks in advance!

 

 

PS. These are the Cura settings I am using:

Material: PLA (Even though it is Willowflex, not PLA)

Nozzle: 0.4mm (My printer is fitted with a Ruby Olsson nozzle)

Layer height:0.1

Initial layer height: 2.7

Wall thickness: 0.8

Top/bottom thickness: 0.8

Infill density: 20%

Enable retraction: (yes)

Retraction speed: 45mm/s (Willowflex recommends 100mm/s but the U2+ only allows me to go to 45mm/s)

Retration distance: 6.8mm

Print speed: 30mm/s

Infill speed: 30mm/s

Wall speed: 30mm/s

Outer wall speed: 30mm/s

Inner wall speed: 30mm/s

Top/bottom speed: 30mm/s

Initial layer speed: 30mm/s

Travel speed: 115mm/s

Enable print cooling: yes

Fan speed: 100%

Regular fan speed: 100%

Initial fan speed 0%

Regular fan speed at height: 0.27mm

Regular fan speed at layer: 2

Minimum layer time: 10s

Lift head: yes

Generate support: no

Build plate adhesion: Brim 8.0mm

Tension on back of feeder: one small notch down from the top

Nozzle temperature: 185C

Build plate temp: set to 0C but usually reads at around 30C

Material flow 170%

I also apply glue stick to the print bed to help with adhesion.

 

Edited July 4, 2018 by PrintingPal

[gr5 2,178]

The failures are underextrusion.  Unfortunately there are dozens of possible causes.  

 

I would squeeze the feeder lever, remove the filament half way and try adding a drop of oil to the filament, then inserting the filament back in.  This can help a lot and won't affect the quality of the prints (really!).

 

Also try printing a bit slower even though 30mm/sec is on the slow end, try 20mm/sec.  Or when it starts failing go into the TUNE menu and play with feedrate % (66% will convert 30mm/sec to 20mm/sec).  And play with temperature.

 

Did you do a cold pull after you did the failing print and before the good one?  If so maybe it was a partial clog.  If not then probably not a clogged nozzle ?

 

When it fails look at the filament in the bowden and near the feeder and see if there is something obvious (maybe the filament is curling up instead of moving along the bowden or getting tangled in the feeder).

 

 

[kmanstudios 1,120]

All of @gr5's advice is spot on. But I did some looking around and this is a new filament. Not a lot of information about it, but they apparently do have a forum.

 

Basically, you are treading on new ground with this stuff. I look forward to hearing your thoughts. To me, that says more than reading an ad piece. Ads cherry pick information. Users call it like it is.

 

Welcome to the community and please keep us in the loop! :)

[PrintingPal 0]

17 hours ago, gr5 said:

The failures are underextrusion.  Unfortunately there are dozens of possible causes.  

 

I would squeeze the feeder lever, remove the filament half way and try adding a drop of oil to the filament, then inserting the filament back in.  This can help a lot and won't affect the quality of the prints (really!).

 

Also try printing a bit slower even though 30mm/sec is on the slow end, try 20mm/sec.  Or when it starts failing go into the TUNE menu and play with feedrate % (66% will convert 30mm/sec to 20mm/sec).  And play with temperature.

 

Did you do a cold pull after you did the failing print and before the good one?  If so maybe it was a partial clog.  If not then probably not a clogged nozzle ?

 

When it fails look at the filament in the bowden and near the feeder and see if there is something obvious (maybe the filament is curling up instead of moving along the bowden or getting tangled in the feeder).

 

 

 

Thank you for the advice @gr5! I will give it a go and report back.

 

I tried using a higher temperature before and the extrusion was better - I went up to 225C but then the nozzle would smoke before the print started. The prints came out darker in colour too so the filament was burning (see pics below). I am also not sure what effect that higher temperature has on the properties of the filament and if it releases any nasty fumes - the recommended temperature for Willowflex is between 175-185C. 

 

Left print: darker printed at 225C , right print: lighter printed at 185C

 

I actually cleaned the nozzle using the Atomic method between Print 1 and Print 2 - because I thought Print 1 was underextruding - which turned out to be nothing compared to the underextrusion that followed! I will check for obstacles, maybe something got caught during the cleaning process - because the filament is flexible, the end was a bit stringy when I removed it.

Edited July 5, 2018 by PrintingPal

[PrintingPal 0]

15 hours ago, kmanstudios said:

All of @gr5's advice is spot on. But I did some looking around and this is a new filament. Not a lot of information about it, but they apparently do have a forum.

 

Basically, you are treading on new ground with this stuff. I look forward to hearing your thoughts. To me, that says more than reading an ad piece. Ads cherry pick information. Users call it like it is.

 

Welcome to the community and please keep us in the loop! ?

Thank you @kmanstudios! I will report back.

[kmanstudios 1,120]

12 minutes ago, PrintingPal said:

I went up to 225C but then the nozzle would smoke before the print started. The prints came out darker in colour too so the filament was burning (see pics below).

This sounds like there may be a bit of moisture. May being the operative word. But if there is no popping or sizzling, then it is probably not the case.

 

I have gone way higher on filament temps just to see what would happen. But there should be no issues with the recommended temp. Maybe 5°C one way or the other, but I would think this is something else causing you issues.

[PrintingPal 0]

Thank you @gr5 and @kmanstudios for your advice. I have found some settings that have a consistent extrusion - it is not perfect - it over extrudes and the print needs to be cleaned with a scalpel afterwards but this is currently more favourable than underextrusion. Work still needs to be done to optimise the print quality but the following settings are doing the job reasonably well for now (see picture attached). The settings in bold are ones that have changed and the non-bold ones are the same as above.

 

Cura settings:

Material: PLA (Even though it is Willowflex, not PLA)

Nozzle: 0.4mm (My printer is fitted with a Ruby Olsson nozzle)

Layer height:0.1

Initial layer height: 2.7

Wall thickness: 0.8

Top/bottom thickness: 0.8

Infill density: 20%

Enable retraction: (no)

Print speed: 12mm/s

Infill speed: 12mm/s

Wall speed: 12mm/s

Outer wall speed: 12mm/s

Inner wall speed: 12mm/s

Top/bottom speed: 12mm/s

Initial layer speed: 12mm/s

Travel speed: 46mm/s

Enable print cooling: yes

Fan speed: 100%

Regular fan speed: 100%

Initial fan speed 0%

Regular fan speed at height: 0.27mm

Regular fan speed at layer: 2

Minimum layer time: 10s

Lift head: yes

Generate support: no

Build plate adhesion: Brim 8.0mm

 

Ultimaker tune settings:

Tension on back of feeder: one small notch down from the top

Nozzle temperature: 195C

Build plate temp: 45C

Material flow: 210%

Retraction distance: 6.5mm (default when retraction is unticked in Cura)

Retraction speed: 25mm/s (default when retraction is unticked in Cura)

I also apply glue stick to the print bed to help with adhesion.

I greased approx 50cm of the filament between the feeder and the spool with a drop of cooking oil.