hairy prints

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chang
Posts: 45
Joined: Thu Aug 14, 2014 3:13 am

hairy prints

Post by chang » Sun Dec 07, 2014 10:27 am

Bought a new roll of OEM ABS filament.
It prints ok, but it creates this hairy surroundings. (don't know what to call it)

Anyone know why the filament behave like this? Maybe it is the high nozzle temp.
Btw: White filament from the same source prints clean.
Attachments
sen78.jpg
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caesar
Posts: 64
Joined: Sat Feb 22, 2014 1:32 am
Location: Romania

Re: hairy prints

Post by caesar » Sun Dec 07, 2014 2:36 pm

My own opinion: it is not real Up filament... It just looks like extremely cheap, vey low quality filament.

Maybe the seller used OEM in its normal meaning: compatible filament but not original. Although compatible filament should work when named OEM.
Judging by how it looks, a 25-30C drop in temperature would make that more printable (not perfect) but you would need a temperature mod.

roller
Posts: 1622
Joined: Sat Oct 06, 2012 9:09 pm
Location: Brisbane, Australia

Re: hairy prints

Post by roller » Mon Dec 08, 2014 1:58 am

Caesar, should I ask why I am quoted in your signature ... oh dear ... surely I've said stupider things :)

I agree with Caesar in that it looks like it is not a genuine filament... that said it is possible to have a fault that causes the extruder to fail on retration which will produce the same results. I have never seen such a failure on an Up though so I suspect this is unlikely. If you want to investigate this possibility:
1) check your extruder gear teeth are not clogged with ground filament powder
2) check all the cable to your extruder by unplugging and replugging them including the rainbow ribbon cable.

You can get this effect when the extruder works fine moving slow but fails when moving fast due to mechanical issues (1) or electrical loss of current/weak stepper (2). The retract moves by the stepper are faster than the forward moves to push out filament. Again though, I have never seen this happen on the Up - it is much more common on high speed printers when we push the extruder close to its speed limit so the fake/non-OEM filament scenario already suggested is much more likely.

chang
Posts: 45
Joined: Thu Aug 14, 2014 3:13 am

Re: hairy prints

Post by chang » Mon Dec 08, 2014 3:27 am

roller, there is nothing wrong with my UP Plus. Everything is perfectly adjusted. I said in my original post 'White filament from the same source prints clean.'

I'm printing now white filament from the same source - and it prints clean.
See attached picture.

I think I need a temp mod. That's why I contacted you.

However it is very easy to remove this excess parts with a file (rasple) and after an acetone treatment.
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white92.jpg
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DrewPetitclerc
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Re: hairy prints

Post by DrewPetitclerc » Mon Dec 08, 2014 6:12 am

Remember everyone!
All plastics are not the same, no matter who you get it from, even the same seller but different batches can act very different, all blends of plastic and the color and chemical additives WILL change how it prints, even "OEM" plastic direct from an approved "UP" reseller will produce different results from spool to spool or color to color, sometimes the difference is so slight that you don't notice or care, every other time you will need to make adjustments.

OEM means you bought it directly from the official manufacturer of the device it is intended for or a direct VAR (value added reseller) and that the product was formulated only for the machine intended, I would be willing to bet that upon closer inspection of the sellers add copy you could determine the true origin of the product and understand the risks you take in using it.

It still amazes me when people get bent because they ignore the common sense signs and don't understand or fail to read the postings here on the forum that will help them make informed decisions.

Regards
Drew
Drew Petitclerc
Petitclerc Designs
Owner/Senior Principal Designer, prototype, tooling and test equipment design and 3D printing
http://flash-graphics.deviantart.com/
http://www.thingiverse.com/DrewPetitclerc

roller
Posts: 1622
Joined: Sat Oct 06, 2012 9:09 pm
Location: Brisbane, Australia

Re: hairy prints

Post by roller » Mon Dec 08, 2014 8:47 am

chang wrote:roller, there is nothing wrong with my UP Plus. Everything is perfectly adjusted. I said in my original post 'White filament from the same source prints clean.'
Oops, missed that bit - I could have saved myself so much typing. Now it might be a quirk of the photograph but that doesn't look like genuine Up white either.

ggeezer
Posts: 12
Joined: Thu Sep 12, 2013 2:19 am

Re: hairy prints

Post by ggeezer » Fri Dec 12, 2014 10:59 pm

I'm speaking as a plastics professional with 50 years of experience in the field and have dealt with almost every problem imaginable. I also have over a year of hands-on experience with FDM printing and have dealt with many problems.

The number 1 reason you get "hairy" prints is moisture. ABS is mildly hygroscopic and can acquire moisture in two ways. It has absorbed it somewhere between the extruder and your home; or the extruder of the filament did not sufficiently dry his feed stock before extruding.

This can cause printing problems in three ways:
1. If the filament has absorbed the moisture sometime after extrusion, the heat of melting turns the moisture to steam. The steam pressure adds to the mechanical feed pressure to change the extrusion characteristics of the print head. The steam pressure also defeats the extrusion cut-off process where the extruder reverses slightly to break the filament as the head moves to a new location. The steam pressure however keeps feeding material which ends up as hairy strings.

2. If the moisture is trapped in the filament at the time of extrusion, it often ends up as trapped bubbles in the filament. I have had filament that was just full of these bubbles. Depending on the frequency of the bubbles, this filament will print reasonably well except that the surface of the part often is lumpy. The lumps are caused by the gas bubbles expanding and making the extrusion flow erratic. The bubbles may not be moisture but contamination problems in the extruder that cause gas bubbles to form from the degrading of the feedstock. The effects on printing are the same.

3 The moisture or trapped gasses can also cause print head jamming.

Fortunately, ABS is mildly hygroscopic and working with it in the mid-west where the air is dry, particularly in the winter, my bubble free ABS usually prints well. Trapped moisture also doesn't effect the properties of the ABS.
This however is not the case with my frequently printed nylon. I opened a new bag of Taulman Bridge nylon and tried to print it yesterday... it fuzzed like crazy and after a while, the print head jammed. I will have to dry it.
Moisture however does effect the properties of nylon so it needs to be dry to have maximum strength.

chang
Posts: 45
Joined: Thu Aug 14, 2014 3:13 am

Re: hairy prints

Post by chang » Sat Dec 13, 2014 2:59 pm

Thanks ggeezer for your insight information.

Maybe reason 1. is the cause of my problem.

My location is Bangkok. My 3-D printer is in a hot office. During working time the aircon brings the temperature down to 25 C.
Off hours the room temperature may go up to 40 C +.

I use different color ABS and keep unused rolls in the original plastic bag with those small dehumidifier sacks.

I wonder why some other color ABS from the same source print fine?

If some ABS contain more moisture than others, is there a way to dry it?

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wilsonj
Posts: 569
Joined: Tue Feb 28, 2012 10:26 pm
Location: Australia

Re: hairy prints

Post by wilsonj » Sat Dec 13, 2014 7:51 pm

Maybe just take a photo of the reel, so we can see it. I doubt it is genuine either.

Different colours from the same ABS "brand" will perform differently. So it is still quite possible the white is non genuine, but works better than the red.
Regards
Jamie
3DPrinterGear.com.au

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