Filament stops flowing (nozzle blockage) randomly during printing

Share your successful printing settings with others here. If you have any question about the parameters or printing skills of some filament, please find here.
Kevin Nicholas
Posts: 17
Joined: Wed Dec 04, 2019 4:18 pm

Filament stops flowing (nozzle blockage) randomly during printing

Postby Kevin Nicholas » Tue Dec 08, 2020 8:23 am

Hi
We have a Raise 3D Pro 2 plus
We have had it for two years and it has always been a bit temperamental running consistent prints.
It seems that some reels of filament behave better than others.
We have just had a very good run with reliable printing from both left and right extruders. But all good things come to an end and I have just replaced both filament reels.

They both load OK but during print after printing for a random time they both simply stop extruding part way through the print.
This definitely happened after loading brand new filament.

If left unattended the filament drive simply grinds the filament sometimes distorting it enough to make removal impossible without cutting with a scalpel top and bottom of the ground and dis formed filament (a hard task to perform) dismantling the hot end and pulling the filament down and out of the machine whilst pulling the other part back out of the top.

If caught in time (whilst still hot) the filament drive tension screw can be removed and the filament pulled out of the top. when this happens ""I notice the filament has formed a sort of plug by expanding into the tube somewhere in the hot end assembly"" and this stops the filament going into the hot end.

By experimenting I have discovered that this tends to happen when the hot end is running a little cool because I can make this happen by setting a cool temperature starting a test print the flow stalls and you can hear the drive wheel clicking as it stalls. Then manually turn up the nozzle temp until it flows OK and resumes printing.

I ran some tests on the nozzle temperatures using a couple of thermocouples and a meter and discovered that the temperature inside the nozzles was about 10 degrees cooler than what showed on the screen and the external temp at the nozzle end shows about 30 degrees cooler. I have changed one of the two temp sensors in the machine and get similar results with the new sensor behaving slightly better by being loser by about 5 degrees or so.

However with the new filament what appears to be the optimum printing temp is by setting it to 70 degrees as read on the screen which is a massive offset. and it still skips the odd time when feeding the filament. I am concerned because if the hot end is set so hot the same problem arises but this time due to the filament getting to soft before it enters the hot end and blocking the feed in that way.

I am now into day 2 of trying to get this machine to print reliably again.

Has anyone else experienced this? we mainly use filament from Filamentive
We also have a BCN3D printer which runs the filamentive filament like a dream with none of this faffing about.

I have spoken to support at 3DGBRE who whilst being very helpful are not in a position to explain to me really why I am having these issues simply offering advice like change the temp sensor which I have done as apparently they do drift during time which would explain the difference between the new and the old sensor when I ran the tests.

User avatar
Vicky@Raise3D
Posts: 8066
Joined: Fri Mar 25, 2016 3:54 am

Re: Filament stops flowing (nozzle blockage) randomly during printing

Postby Vicky@Raise3D » Wed Dec 09, 2020 2:31 am

What brand/type of filament are you having the issue with? Is it mainly one brand or multiple that are causing issues?

Kevin Nicholas
Posts: 17
Joined: Wed Dec 04, 2019 4:18 pm

Re: Filament stops flowing (nozzle blockage) randomly during printing

Postby Kevin Nicholas » Wed Dec 09, 2020 11:05 am

We are using Filamentive https://www.filamentive.com/

Kevin Nicholas
Posts: 17
Joined: Wed Dec 04, 2019 4:18 pm

Re: Filament stops flowing (nozzle blockage) randomly during printing

Postby Kevin Nicholas » Wed Dec 09, 2020 11:14 am

Update.
After lots of testing and replacing the nozzle with similar results I decided to speed up the first layer a bit so that the filament would continue to flow at a reasonable rate.
I also changed filament from Black to Orange both new reels but the Orange seems to flow more freely.
This has improved things immensely. I suspect the very slow first layer is causing the filament to expand as it stays in the nearly hot zone for much longer and forms the plug. If it manages to get to the second layer the blockage is still there and will then cause this random filament flow stoppage.
However this means the filament is more liable not to stick to the bed as the slow first layer is designed to ensure good adhesion to the print bed.
So currently I am printing with the temp at 220 degrees as read on the screen which in reality is closer to 210 degrees due to the offset in the temperature sensor.
I will run the same print with the same settings using the black filament.
I will also buy some Raise 3D filament from 3DGBRE so that I can compare performance.

User avatar
Vicky@Raise3D
Posts: 8066
Joined: Fri Mar 25, 2016 3:54 am

Re: Filament stops flowing (nozzle blockage) randomly during printing

Postby Vicky@Raise3D » Thu Dec 10, 2020 1:37 am

It is difficult to say if the filament you are using would work correctly as we have never tested it. Due to the fact that the machine is fully encloused it does make it a little more subseptable to things like heat creep. This is why it is important that while running any type of temperature sensative materials in the machine like PLA that you keep the top lid off to avoid such problems.

Kevin Nicholas
Posts: 17
Joined: Wed Dec 04, 2019 4:18 pm

Re: Filament stops flowing (nozzle blockage) randomly during printing

Postby Kevin Nicholas » Thu Dec 10, 2020 1:22 pm

Hi Vicky
Yes I have the top cover off.
Its looking more likely to be a problem with the filament.
I have managed to complete one good print using a reel of Orange filament form Filamentive. however swapping the filament to Black the problems reappear.
I went back to using the original basic profile that comes with the idea maker that also failed and in fact the filament did not flow at all unless I put up the nozzle temperature (whereby we get this soft plug forming in the feed)

I have since swapped the filament for some Raise 3D filament and that prints OK using the original profile temperatures as reccomended.

Its looking very much like the Filamentive filament will not print in the Raise 3D printer.
I am purchasing two new reels of the Raise 3D filament and will use that as a comparison.

At this time I am still not sure why but will take this up with the manufacturer and feedback any advice they may give me.

Kevin Nicholas
Posts: 17
Joined: Wed Dec 04, 2019 4:18 pm

Re: Filament stops flowing (nozzle blockage) randomly during printing

Postby Kevin Nicholas » Tue Dec 15, 2020 8:09 am

Update.
I tried some filament from the Robox printer and that also causes the plugging effect.
The only filament that works OK is the Raise3D filament.
The do look and feel different the Raise 3D filament is less opaque and can't be snapped as it bends and needs twisting to break or cutting with cutters. The other filaments can be snapped.
So its an obvious difference in filament material although its PLA the Raise 3D filament is very different.
However I used to be able to print with any PLA filament so what has happened??
Why do I get this random blocking up during a print.
I can only guess its something to do with the nozzle and the way the filament is fed through the hot ens where the filament is allowed to expand into the space before it goes into the nozzle and when this happens it is cooler and actually stops the feed.
Vicky@raise3D please can you advise I can't believe Raise 3D have not seen this.

User avatar
Vicky@Raise3D
Posts: 8066
Joined: Fri Mar 25, 2016 3:54 am

Re: Filament stops flowing (nozzle blockage) randomly during printing

Postby Vicky@Raise3D » Wed Dec 16, 2020 3:24 am

If you have noticed any issues with the front fan? It should be spinning at 100% at all times as soon as the machine is powered on. If it is not, heat creep can occur causing the filament to expand and jam.

Kevin Nicholas
Posts: 17
Joined: Wed Dec 04, 2019 4:18 pm

Re: Filament stops flowing (nozzle blockage) randomly during printing

Postby Kevin Nicholas » Tue Jan 05, 2021 8:50 am

Thanks Vicky
The front fan is a bit noisy I will replace it with a new one.
I agree its probably heat creep that is my problem as its so random.
and if the fan has been failing it would explain why the issue has been getting progressively worse.

User avatar
Steven@Raise3D
Posts: 415
Joined: Thu Dec 17, 2020 11:24 pm

Re: Filament stops flowing (nozzle blockage) randomly during printing

Postby Steven@Raise3D » Wed Jan 06, 2021 12:56 am

Kevin Nicholas wrote:Thanks Vicky
The front fan is a bit noisy I will replace it with a new one.
I agree its probably heat creep that is my problem as its so random.
and if the fan has been failing it would explain why the issue has been getting progressively worse.



Definitely, the front fan is imperative to ensure that heat creep does not occur.

Kevin Nicholas
Posts: 17
Joined: Wed Dec 04, 2019 4:18 pm

Re: Filament stops flowing (nozzle blockage) randomly during printing

Postby Kevin Nicholas » Fri Jun 25, 2021 7:29 am

https://forum.raise3d.com/viewtopic.php ... 756#p54808

Here is somebody with the same filament issue.

User avatar
ccclarke
Posts: 163
Joined: Wed Apr 08, 2020 6:09 pm

Re: Filament stops flowing (nozzle blockage) randomly during printing

Postby ccclarke » Fri Jun 25, 2021 6:54 pm

Kevin Nicholas wrote:Thanks Vicky
The front fan is a bit noisy I will replace it with a new one.
I agree its probably heat creep that is my problem as its so random.
and if the fan has been failing it would explain why the issue has been getting progressively worse.


Had the same problem and this solved it: https://www.frozencpu.com/products/2438 ... d=8u8mcbZm

Apparently, this fan is putting out more air than the stock fan and after a year of flawless operation, the printer experienced it's first heat creep-related issue last week. The guy who started the print used a spool of non-approved Extech filament with predictable results. After replacing the spool with approved filament, no problems. I spliced the old connector / wire in place, which took about two minutes. This was a very cheap fix!
Male Modeler / Sub-Human

Robodad
Posts: 2
Joined: Tue Jun 22, 2021 5:43 pm

Re: Filament stops flowing (nozzle blockage) randomly during printing

Postby Robodad » Tue Jun 29, 2021 2:58 pm

I've followed this thread with great interest. Thanks for the great info and suggestions. I'm running MH Pro PLA and started to experience massive clogging problems. I turned up the temp 5-10 deg, added Gcode for a starting purge line and ordered the fan. So far so good.
Also suffering the same clogging issues using MH NylonX and Ionic PVA - I suspect heat creep. I know this is a different thread but does anyone have some settings advice?
Is there an accessible area in the Raise3D SW to calibrate the thermocouples?
Thanks again!

User avatar
Steven@Raise3D
Posts: 415
Joined: Thu Dec 17, 2020 11:24 pm

Re: Filament stops flowing (nozzle blockage) randomly during printing

Postby Steven@Raise3D » Thu Jul 01, 2021 1:57 am

Kevin Nicholas wrote:https://forum.raise3d.com/viewtopic.php?f=18&t=20537&p=61756#p54808

Here is somebody with the same filament issue.


Would you be able to attach a few images of your printhead and hotend assemblies?


Return to “Printing Settings”

Who is online

Users browsing this forum: No registered users and 3 guests