Furry prints ... how to get rid of the hair ...

[ultiarjan 1,221]

good idea! I've send you a message ....

 

[pm_dude 27]

Thanks I'll try it out in a few hours.

Actually I can get the same fury effect when printing a tube standing up. I'm sure it as nothing to do with the slicing.

It must have something to do with the material and settings used.

Anyhow I'll post some pics later

 

[pm_dude 27]

Small update:

 

Print #1 Ultimaker Ultimate-Blue PLA

 

No fur. This means the slicing is not the issue. Printed at 220C at first and reduce to 210C while printing the base. I can spot one or two hair inside.

 

 

 

Print #2 Colorfabb Dutch Orange PLA

 

So far so good. Still too early to tell. I'll post results later.

 

 

Possible things that could be happening:

Is there a big change in room temperature that could quickly change print volume temp? Check for very high humidity, air conditioner or fan blowing almost directly toward printer.

 

[pm_dude 27]

Here come print #2-3-4

So I tried all I could to make this happen and in the end I got some but with woodfill which even then is not even close to your result.

Here are the details. Please follow using the black lines from bottom to top:

Colorfabb Dutch Orange (Prod: May 8 2014)

- Started like the previous one at 220C and reduced at 210C during base.

- First line: stop the fans completely, kick the air conditioning right in front

- Second line: set the fan one again, no air conditioning, raised progressively to 240C

- Third line: set temp from 240C to 210C (the nozzle dropped to 195C causing underextrusion)

- Fourth line: Changed to Ultimaker Metallic-Silver which I sometime get furry prints with.

- Fifth line: set Material Flow at 130%

- Sixth line: Pause print, tried sticking some filament on the nozzle. so far the nozzle was staying completely clean. More than usual. When sticking plastic on nozzle it was sticking a bit on it but not with the same behavior as I'm used to. As if something was making it not bounding to the nozzle. I have cleaned my nozzle with extra fine steel wool recently to get rid of some nasty burns. It may have helped prevent bounding but could also damage the nozzle (maybe?).

- Switch to Colorfabb Woodfill Fine (Prod: March 13 2014) and raised flow at 110% and speed at 200% (making it go at 80mm/s) because these are 0.1mm layers and its not recommended for woodfill. Finally got a few fur/webbing.

There is clearly something missing here because I had many prints with Ultimaker Metallic-Silver having some fur and this time none. The clean nozzle is also something weird because usually I can see a tiny but of plastic on the tip of the nozzle and this time I got nothing at all.

 

[gr5 2,005]

@pm_dude - I think that's just normal stringing. Not the fur in the original post (post #1).

 

material was not nicely going straight down, but more on one side,

 

Hmm. Interesting.

 

tried sticking some filament on the nozzle.

 

lol. And that still didn't do it? That is the test I would recommend. I thought maybe the fur is what you get with a nozzle with melted pla on it. I think I'm pretty good at keeping the nozzle clean. Right when the print starts I grab the bit coming out. Never burnt my fingers. Just be fast.

 

[DidierKlein 729]

Want to see my fur?? :mrgreen:

This is a bust i printed yesterday with BioFilla Linen:

 

A lot of fur every where. It's very thin my guess is that it's thinner than real hair.

 

I will have a timelapse (tonight) of the print maybe it will show something?

 

I thought about it during the night (yes i sleep badly) here's my twisted theory on this:

 

Let's imagine that the nozzle puts some extra material at random places and that the fan blows on it creating a small hair.

 

It's so small that it would stay in glass transition due to the heated bed and the nozzle head.

 

So every time the fan blows on it, it grows a bit making it even more thin, thus more subject to the phenomenon

 

[ultiarjan 1,221]

@pm_dude, thanks for your testing!

About my printroom; it's around 20 celcius, heating is off atm, no airco, no drafts I can notice. I have no idea about the humidity, wouldn't know how to measure it ....

I was most surpriced by how fast my nozzle got dirty again, so I'll clean till I'll get a nice straight flow of material again, If needed Ii'll change the nozzle with a new spare one (have one in stock).

Try to continue testing tonight... but not sure if I'll get to it...

@Didier, if you have a look at your timelaps, please let us know how dirtty (or clean) your nozzle was ....

 

[DidierKlein 729]

My nozzle get dirty quite fast, i try to catch the filament during priming but it gets often covered in PLA.

I'll have a look tonight at the pics to confirm this. My previous print was the same bust just smaller with faberdashery filament and there was no hair at all (and i didn't clean the nozzle between the prints

 

[markus-reinisch 0]

I print a lot with colourfabb PLA and sometimes when I print to hot I get this hairy look.

Normal I print with 195 degrees and 40mm/s.

 

[3dmaker4u 0]

It looks to me a combination of:

- oozing filament (you know that color can make the difference, even for the same manufacturer)

- too high temperature (especially true for the above, where a few degrees may count)

- too much fan well, I thing this is how the fur is spreading everywhere

The images remembered me about cotton candy, produced from sugar melted in a heated drum, blown by a fan and collected as "fur" on a... stick

 

[gr5 2,005]

It's a beard?

 

[DidierKlein 729]

It's a beard?

 

Yes but it's actually a woman :mrgreen: :mrgreen:

Here's the timelapse of the print.

My nozzle was covered in white filament when i checked it today. Was too lazy to clean it up now my print in black PLA has fur all over the place. I really do think that the dirty (dirty) nozzle is the cause of this...

 

 

[ultiarjan 1,221]

THE FUR IS GONE !!

so I started cleaning my nozzle this evening, tried poking it with a skewer, did a few "atomic pulls" but did not get a nice clean tip after an atomic.

Decided to go al the way and change my teflon piece and nozzle for a new one. Actually the old teflon did not look so bad, just a little brim, the nozzle was coated with dirt on the inside....

Now with the new gear, PERFECT MATERIAL FLOW, i did see a buildup of PLA on the outside of the nozzle during the first layer, but it has cleaned itself during printing later on, it's still printing atm and the nozzle is perfectly clean.

So now I want to clean the old nozzle, I read here somewhere people are using a gas torch for it, but how do you actually do that ? Is there a danger of damaging the brass by overheating easily ?

 

[pm_dude 27]

THE FUR IS GONE !!

Awesome!

 

[pm_dude 27]

I guess this could be a good subject to add to the visual troubleshooting guide (Furry effect or Cotton candy)

 

[ultiarjan 1,221]

agree, just added a link to this topic in the "visual guide" thread

 

[ultiarjan 1,221]

And although some people here complain about the high price of spare parts (I know I'm lucky to live in the Netherlands looking at the shipping cost..) I thought replacing the parts like I just did was not so bad after I got this in my mailbox

Reminds me I talked to a makerbot guy at the 3d printshow on saturday and asked him about cleaning nozzles just to have a little bit of fun ... answer; your not supposed to take them appart, you can just click on another one .... bit of a pricy machine to maintain .....

 

[pm_dude 27]

Not the first comment similar to this that I get about how rigid they are against using anything but PLA.

Its not that expensive... They come in pack of 3

 

[pdrinkut 3]

just wanted to add that I had this same issue with the first print I tried with colorFabb white. I then switched material and did another print with no problem. Going back to the white I literally had a dog hair clog in my nozzle (husky owner problems). After cleaning the nozzle I tried the white again, three different UM robots at three different temps (200,210,220) and no hair problems. I did notice that some hair fibers were on the fan shroud after the robot prints when the shroud was clean before printing.

 

[ultiarjan 1,221]

we also have a dog .... but he's not allowed in my printing room

 

[gr5 2,005]

Heating the brass is somewhat dangerous as it can melt. However the melt point is about 940C so I doubt you will have a problem if you are careful - don't leave it in the flame continuously - maybe 10 seconds at a time. Make sure everything turns to carbon ash.

Also consider soaking it for an hour in a solvent (like acetone) although I never did this myself. Acetone is good at dissolving ABS but not PLA. Ethyl Acetate will destroy any PLA (not dissolve exactly - more like make it weak and brittle).

Definitely test it while still not connected to your printer by putting some PLA through it to make sure nothing is clogged - of course you have to heat it with flame first.

 

[ultiarjan 1,221]

Ill try to burn it clean in the weekend. No hurry as its a spare now... may even try to drill it to 0.6 for experimentation but wonder if its possible by hand held dremel? I suppose if you dril from the inside theres some guidance... ever tried it?

[pm_dude 27]

You might want to look at this thread for a starting point

http://umforum.ultimaker.com/index.php?/topic/6557-help-with-drilling-out-nozzle/?hl=%2Bdrilling+%2Bnozzle

 

[ian 32]

i still suffer from poor underextrusion even with everything cleaned and the new fibre glass teflon part. So I have found by raising the nozzle temp to 250... the filament flows out like butter with almost no feeder clicking...

the only problem is... i do get great finishes but with this bunny fluff effect....

Any idea how to best remove bunny fluff from a print ?

I have just been washing and picking it off but was wondering if there is another way ?

 

[pm_dude 27]

250C is very high. Is it PLA your printing?

You might have too few or too much tension in the feeder. Try printing a small cylinder 0.1mm layers, 25mm wide, 5mm high (like a coin) at 40-50 mm/s. while its printing play with the tension of the feeder and see if you can get rid under extrusion.

That is how I manage to get rid of my under extrusion problems and get back to printing pla at 210C and be able to print at 80mm/s without underextrusion.

Its not my technique. I found someone here that does this too but cant remember who it was...