Blockage/ Clogging

[Pj_Doyle]

Hey guys,

Back again with a brand new problem, since ye helped a lot last time I was hoping for some more great advice for my Vertex K8400.

Im printing 1.75mm PLA @ 215 degree celcius. Now a couple of days ago it jammed and took me a while of poking and pulling to unclog the nozzle with no results. So yesterday I took it apart and done it right, took me the day to take the nozzle apart, burn out the plastic from the nozzle and poke out the PLA from the barrel re assemble it.

Everything was working perfectly again and the fillament fed in and extruded nicely, so I decided to run a test print, half way through… THE SAME THING HAPPENED… very very frustrating.

Now my theory is the nozzle is too old and adding to that the two fans stopped working on my hot end when I was trying to take out the jammed PLA.

1. Does anyone know why its jamming and how to fix it?

2. Everything seems OK with the fans (wiring looks normal) does anyone know what might be causing this?

Cheers,

PJ

[GIFT3D]

Hey Pj,

The cause of the blocking may is the way the filament goes into the printer. If it catches on a part then small pieces start pealing off which means it gets blocked. Sometimes the filament may have a sort of string round the filament, which is a similar thing. To get rid if this you can add various objects that will knock it off like passing it through a tight plastic piece or a piece of sponge.

If your nozzle keeps blocking use some acetone and add it into the nozzle, this will liquify the clogged plastic causing it to drill out. Be careful though as it is a flammable substance and has dangerous vapours. This should be added when the printer is off and cool. Don’t worry when the printer makes an unusual noise when it turns on, this is just the acetone evaporating. Hopefully this should be easier to do than take the printer parts apart and won’t waste as much time. I always have acetone to one side for such instances and it’s great for making slurry and glues for your prints.

I hope this helps. If you have any further questions just ask and I’ll try to help.

[Pj_Doyle]

Hi Kane,

On the K8400 there is nothing for the fillament to catch on to as it is fed through a hollow tube from the feeder to the extruder with no contact to anything but the hollow tube, the plastic barrel and the hot end.

So basically its one smooth journey.

I think the problem maybe due to temperature at the hot end and lack of cool air from the non functioning fans… But really I’m not sure…

The barrel of the hot end is made of plastic and this is where i suspect the fillament is originally getting clogged. Acetone might damage the Barrel. But i did use it on the nozzle however it is not as effective on PLA as it is on ABS.

Regards,

PJ

[GIFT3D]

Hey PJ,

you may be right about it clogging due to the barrel. I understand that there are no parts for the filament to catch, but sometimes the filament comes with a stringy plastic wrapped round the filament. I’m not sure what else could be causing the problem. I hope you get an answer and fix your printer.

[Filemon]

Administrator Note: @Pj_Doyle please don’t forget to add tags to your posts in order for the community to get notified. I’ve added this one (Velleman) for you. Cheers!

[TH3_Downer]

215 degrees i way to high it will caramlize the PLA , lower the temp to 190 - 200

[Jan_Lauwers]

Have the same problem… and for a loooong time allready know :(. this friday i will take it back to the

store where a representative of velleman will do some test on him. I will let you know what the problem

was and ho to fix it as soon as it gets back. (it will take a few weeks…)

grtz

Jan

[Pj_Doyle]

Velleman recommendations are 210… ill give it a go at 200.

I use 215 as the first layer sticks better to the print bed.

[3DVisio]

Also got this problem sometimes… i think it mostly occurs, when PLA gets too hot inside upper area of ceramic cooling element. So, I now always get fans on manually at about 30-40% output performance when heating up noozle to keep this part cool enough.
When PLA is jamming, i used to turn out the quick connector in hot state. Because of the power of thread, jammed PLA mostly gets out of noozle slowly and cooling element then. When trying to get out PLA by strongly dragging, it mostly gets ruptured anywhere inside cooling element, and then, I got it pushed through with a 1.5mm hex wrench. If this doesn’t work too, deassembling extruder is the last way solution…
When noozle is free again, i use to heat up and do a quick feed with 50 or 100. Often, some more burned PLA comes out first, before it gets a nice flow again.
Just after heating up and before start printing, i always do a 10 quick feed to get out burned PLA from heating phase.
While printing, i used to let fans run at about 30-40% (so, that temperature just doesn’t sink below 200/205 degrees). This will avoid jam in cooling element while printing.
When fans aren’t running (or any error message is shown on display), first try to do a reboot of printer. When starting print, consider that default setting will turn off fans completely on 1st (table plate) layer. When printing things with big ground surface, I turn on fans manually also on 1st layer (some about 10-20%), or sometimes i also got jam before 1st layer is done…
Hope, some of this will help…

[TH3_Downer]

Trust me 200 will do the trick some people print at 190

Regarding the sticking, just put the bed a little close by adjusting the z-end calibration at the back of the Vertex.

[amarbirtakhar]

For creating a “sticky bed” I spray adhesive directly on the glass after removing it from the printer. Then I use it for a print or two. After that, I remove the glass, clean the dried adhesive with goo-gone and water, then repeat the spraying adhesive process. I currently print at 205 with great results at 1mm.

[amarbirtakhar]

PJ,

I love my K8400! Now that I understand all of its quirks I am printing some awesome stuff. I hope to help you with your issue. Let me know if you need some clarification.

Fan issue fix:

Replace parts or improvise.

I had this same exact problem. I burnt out my fans after mistakenly having some leftover superglue from a repair flow down to the board of the hot end. However, the fan burn-out was a blessing because I ended up improvising my set up. I purchased three mini-desktop fans and mounted them in a way so they blow towards the printing surface and the hot-end. Along with an another technique I use for printing my models come out awesome. Like $2000 machine quality awesome for a lot cheaper.

Clogged Nozzle/Cleaning:

A less messy alternative to chemical cleaning.

The reason I always had this problem is because my hot-end would overheat causing the PLA from the top of the isolator to expand just a little bit to where it would become stuck and “underfed” through the extruder. (even when I had everything functioning correctly) So first, you need to make sure your “hot end” or more specifically your isolator remains cool. This will prevent the PLA from expanding in the cold parts of the hot end and not being able to run through. To fix this problem try devising a way to have a fan blowing at the isolator to keep it cool. I’ll post a picture of my set up later if you need ideas.

The unclog a nozzle: I first heat the hot-end to my preferred PLA temperature. Then, I use a very thin wire and insert it into the nozzle while it is hot. Move it in and out to break up the carbonized bits of PLA. You should be able to pull out some melted plastic at this point. Now move to the top of the extruder and unscrew the nozzle going into the isolator guide. (I advise having a fan blowing at the general direction of the hot-end.) Cut the PLA from the isolator guide with a utility knife. Then find a hex or allen key that will fit into the isolator guide. Stick it in there and try pushing out the PLA. If it does not work keep using a wire to break up the PLA at the hot-end nozzle and repeat. You will pull out melted PLA until this process does not pull out any more melted PLA from the isolator guide. Now, screw in the PLA nozzle at the top of the isolator guide. Use repretier host controls to manually extract the PLA through the isolator guide. (do not extract too much material otherwise it will clog again.) Then when you see PLA coming through then you’re golden. So you should be good at this point.

Throughout this process you need to keep your hot-end…hot. This has to be done quickly to minimize another clog.

*please use this advice at your own risk. I had to break a lot of things to get to this method for which is the most reliable way to fix this problem in my eyes.

/Velleman

[mathias3dartist]

Make sure the fans is workin and low er the temp.

[amarbirtakhar]

I like…

[maximilian_3]

hey PJ,

215 is indeed whay to high for PLA, try 190.

The clogging is happening because the nozzle becomes to warm so the pla becomes to early to warm, that whay it will becomes soft and sticky to early

and that result in clogging.

I hope it answer your question.

Regards MK.

[Pj_Doyle]

Love the diagrams, explains it perfectly… What should happen… this is exactly what is not happening me.

The PLA is clogging in the blue zone… because the fans are not working…

If i lower the temperature, could i proceed to use the printer untill the replacement fans arrive?

Regards,

PJ

[Joachim_Hyl_n]

I’m having the exact same problem with filament getting stuck in the isolator. I came up with a solution to get the clog out. Dismount the isolator and place it in the oven at 225 degrees centigrade. After about 10-15 minutes you can pick it out and use a thin tool to remove the clog.

But I don’t really know why this is happening to me. I have made many parts before without any problems. But now I keep getting this problem. Maybe it’s more of a problem with certain parts? That withdraw filaments and jumps in different patterns that makes the filament go slower out of the nozzle?

[Jens_De_Vriendt]

Hi,

I don’t know if you found an sollution but have you checked your retraction distance?

In repetier the standard setting is 9mm which is way too much, it retracts the hot fillament into the ‘cold area’ and it hardens.

my retraction distance is 2 - 3mm max.

I hope this helps

[Hamidsami]

My problem is the printer was working normally and then it started failing to feed. The Bowden slipping the filament is not getting in. I changed the nozzle and changed the heat break and the problem present also now the filament is keep dropping from the nozzle. Any suggestions?