Colorfabb XT-CF20 sticking to nozzle

[AndreasDesmedt 0]

Hey guys,

I'm almost through a spool of Colorfabb XT-CF20 mainly printing small parts. Today I had a 3D Hubs order with some big parts that took up to 6h printing time. I always noticed the blob of filament on the nozzle while printing with XT-CF20 but it never turned into a problem until now.

The blob only grows while printing and when it becomes to big it drop right in the print. When the head passes again it crashes into this blob resulting in the motor skipping steps. Ruining the print, offcource.

I've read about this problem on the internet and also hear on the forum, but I've never found a clear solution for it, if there even is one? I've tried printing slower, different temps, retraction,... Nothing helped.

I have an E3D Hardened steel nozzle, 0.4mm. Would a 0.6mm make any difference?

Are there people that do not have this issue, what are your settings?

Thanks allot in advance, I'm desperate...

Andreas

[GummyBearBandit 2]

General recommendations:  print slow and hot, no fans, enable retraction, set retraction distance to 0.0mm and z-hop to around 0.25mm.

Use tape on your print surface!

Edit:  re-level the bed after every 20m printed or so if you're doing 0.1mm or 0.2mm layers, print in the smallest amount of layers possible, and print with the smallest surface area as the first layer if there won't be significant overhang problems.

If a part you're printing is going to take up more than 20m material in one go and you can't figure out a good enough way to break it up into smaller parts, then consider going with an alternate route such as CNC and/or injection molding.

Edit #2, regarding cool-head lift:  only use it as a testing measure to see if it'll need to be activated.  If it does need to be activated, then use a tower with enough surface area so cool-head lift isn't required.  Otherwise, your print will likely fail.  The minimal reliable extrusion for my purposes is around 1.2mm^3/s with about 20 seconds between layers.

Edited December 26, 2016 by Guest

[neotko 1,417]

General recommendations:  print slow and hot, no fans, enable retraction, set retraction distance to 0.0mm and z-hop to around 0.25mm.

Use tape on your print surface!

 

Tape for CFXT? Colorfabb inly early versions did use blue tape. For example Formfutura CF does work with blue tape.

Edited December 25, 2016 by Guest

[eldrick 65]

According to everything I've ever read about CF printing, you need a steel .6-1.0 nozzle to avoid extremely rapid wear of the nozzle, if for no other reason. Do some web search on the stuff, and you will find an image of a brass nozzle worn to useless after printing 250g of CF filament.

Wiping the nozzle with some silicone lube may also help, by keeping the blob from sticking to the nozzle.

[GummyBearBandit 2]

I've printed a few hundred meters of the CF-20.  My E3D stainless steel 0.4mm and 0.8mm are still working well enough.

I use blue tape, because I print slow and hot enough that the material will pull the glass up off of the print bed.

Edited December 25, 2016 by Guest

[meduza 191]

No tape needed, but i use a liberal layer of glue stick anytime i work with XT to avoid glass damage.

@GummyBearBandit: I am running a test of nozzle wear right now, and the 0.5mm stainless nozzle i used to print about 0.5kg (~65m) is about 0.3mm shorter than before the test. This has also lead to that the outer diameter of the shoulder is doubled which in combination with a shorter channel does significantly alter printing performance.

Edited December 25, 2016 by Guest

[GummyBearBandit 2]

Oh, yeah, I definitely have to re-level the bed after every 20m printed or so.  My parts are still finishing up well enough, though.

Are you also going to test hardened steel, different manufacturer's sizes, and printing methods?

I'm going to add a few more general recommendations to my original reply.

Edit:  I guess for the glue vs. tape debate...use tape, and if the first layer of material goes down well enough, then you probably have nothing to worry about - as long as you're careful about doing touch-up while printing is in progress.  Or use a liberal amount of glue without tape if you're still having trouble sticking the first layer and don't mind possible glass damage.

Edited December 26, 2016 by Guest

[meduza 191]

@GummyBearBandit: I just hate peeling blue tape from my prints when they stick too well... makes for ugly bottom surfaces :/

Right now i am only comparing the Olsson brass and stainless nozzles to the new Olsson Ruby nozzle, for the Olsson ruby website, i have gotten reports of that the hardened nozzles also will also wear in time, but it will require longer time and more material, and i have limited amounts of both time and XT-CF20 to do this

I can report that printing XT-CF20 with a brass nozzle wore it down 0.5mm in 300 grams, and for the stainless steel one it took 1000g to do the same amount of 0.5mm wear, so the stainless nozzles lasts about 3 times as long as the brass, but it also came with the need to print 5-10C hotter wich can affect your print quality.

300g Colorfabb XT-CF20

1000g Colorfabb XT-CF20

@Neotko still has the record for printing most carbon filled filament with a ruby nozzle, about 8kg of the stuff, and no wear was even visible in a microscope, that was pretty impressive :-)

Edited December 30, 2016 by Guest

[GummyBearBandit 2]

 

@Meduza Oh, wow! That Ruby nozzle looks very impressive, almost badass even! Yeah, steel can't compare to that.