Filament abrasion in the feed: Why?

[3design 0]

What could be the reason that filament was abrased inside the feeder unit and stopped to proceed?

Please have a look at the following pictures (filament string which was abrased during printing, object when filament feed stopped, Cura settings):

It is the first time that problem occurred. As it was a five-hour-printout, I would be glad if you told me about the reasons for the problem.

Do you think one of the following could be the reason:

- old filament (might be up to 3 years

- overheated stepped motor in the feeding unit

- long printing time, problem occurred after 3.5 to 4 hrs of printing

- any of the settings chosen (Ultimaker Original, newest Cura version)

I'd be glad about any idea or hint how to fix that issue.

[3design 0]

As there have been no answers since, I decided to repeat the printing.

After a second printing failed (again due to abrased filament), I started a third one where I continually observed the feed.

I concluded that the crux of the matter was in the filament spool. The filament was so densely packed that the filament cycles blocked each other, resulting in slowing down the feed an eventually stopping it. I unwound the entire spool, so the filament was loosely lying on it. Such, I finally could successfully finish the print.

I hope to help others with this solution, the topic can be closed.

Edited January 18, 2017 by Guest

[gr5 2,167]

The photo you showed of the diamond pattern in the filament is normal. That indicates you have a good tension on the filament.

60mm/sec at 210C and .2 layer height is quite fast. That's about the limit I can do on any of my 5 UM printers. I would never print that fast normally - I prefer to go about half that speed. Here is a table of limiting recommended speeds.

ere are my recommended top speeds for .2mm layers (twice as fast for .1mm layers) and .4mm nozzle:

20mm/sec at 200C

30mm/sec at 210C

40mm/sec at 225C

50mm/sec at 240C

Of course the printer can indeed print that fast but barely such that the slightest problem can cause underextrusion and even failure.

In your case I agree it was the tightly wound filament near the end of the spool which adds to the friction both in the bowden and especially in the teflon part in the print head. However I recommend printing either thinner layers or slower speeds or higher temperatures.

[3design 0]

60mm/sec at 210C and .2 layer height is quite fast.  

Of course the printer can indeed print that fast but barely such that the slightest problem can cause underextrusion and even failure.  

 

Looks like I wa lucky with all my prints up to now - you are right, I never really wondered about too high printing speed.

During the 3rd print (with succeeded in the end) i even increased the printing speed on the controller from 100 to 130% - and all went fine.

I will readily try out different speeds or layer thickness, what might help as well with more filigrane objects - some of them I wasn't able to print because the moves of the print head caused them to bow and finally drop off.

Thank you very much for your advice.

[gr5 2,167]

1) Why is the bottom cm or so a lighter shade of red (pink)?

2) Please update your profile to reflect the country you live in because that is important to answering questions more often then you would think!

3) Your parts are small with a somewhat steep overhang. These are tricky to print. You certainly want as much fan as possible. The overhangs will have raised edges on the layer currently printing and the head will hit them and can knock them over. The solution is as much fan as possible and also to make your parts stick so well you can pick up the printer by those little dodecahedrons. Here is advice on that:

 

[LePaul 321]

One thing to add in addition to gr5's excellent response...you can test your old filament pretty easily. Simply bend it and if it snaps apart, it's no good. If it bends and twists and takes a lot of effort to break...that's good.

I also have an Ultimaker Original (and a Ultimaker 2+) On my UMO, I generally print at 40 mm/sec. It's a bit slower but I get great quality. As for temperature, it can vary with nozzles and brand. Standard nozzle and Ultimaker filament, 215-220 works best. ColorFabb PLA/PHA is around 210. I experiment on temps using the Ultimaker Robot test print

[gr5 2,167]

If your filament is brittle - don't throw away the whole spool. Usually only the meter or so that was straightened for several hours in the bowden is bad.

[LePaul 321]

I had a spool of MatterHacker Pro PLA, still in the vacuum bag, it was terrible. It was gold and I was starting to think they sent me a roll of pasta. It was breaking when I tried to unspool it. I figured the first few feet might be bad so I clipped that and fed it into the printer. It broke in many places IN the Bowden tube. Not a lot of fun to clean up