help needed!!nozzle getting jammed during printing what to do?

Hello eneryone!!

Story:
I recently completed building my custom 3D printer with latest marlin firmware 1.1.9 installed in it.I am using Ramps 1.4 controller(on arduino mega 2560) with Repetier Host for priting.
everything works completely fine except 2 major issues and i dont know what is causig this.

Problem:2
Nozzle gets jammed at anytime during print,extruder keeps trying to push it but fails.
I then have to take out the filament out of hotend nozzle and reinsert it(End of filament wire becomes thick)
Things i tried to fix it:
I completely removed the hotend and cleaned it throughly and reassembled it but problem still the same

Edited 4 time(s). Last edit at 08/30/2019 03:19PM by adnanrk.

What exact hotend do you use (manufacturer & type) and how is it cooled (picture)?
One of the most common reasons for this is that the upper part of the hotend, above the heatbrake, get's to hot. This can be due to bad or no cooling, crappy hotend, incorrectly assembled hotend ...

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[www.bonkers.de]
[merlin-hotend.de]
[www.hackerspace-ffm.de]

Quote
adnanrk
Hello eneryone!!

Story:
I recently completed building my custom 3D printer with latest marlin firmware 1.1.9 installed in it.I am using Ramps 1.4 contro

ller(on arduino mega 2560) with Repetier Host for priting.
everything works completely fine except 2 major issues and i dont know what is causig this.

Problem:2
Nozzle gets jammed at anytime during print,extruder keeps trying to push it but fails.
I then have to take out the filament out of hotend nozzle and reinsert it(End of filament wire becomes thick)
Things i tried to fix it:
I completely removed the hotend and cleaned it throughly and reassembled it but problem still the same

There are three common problems:
1- You are printing too cold. Increase your temperature by 5 deg and try again.
2- You are printing a "cooler" filament AFTER you have been printing a hotter one. Print a few meters of the "cooler" filament using the hotter settings.
3- You have inadequate cooling to your heat break. Replace your heat break fan with one that pushes more air, or add a second fan, OR reduce your hot end temperature.

(1) is pretty uncommon, (2) happens to all of us on occasion when we get in a rush. (3) is common as dirt. I suspect this is your case.

So, working with our guess that it is (3) that is your issue, check these things:
See if you have a true "all metal" heat break (vendors lie, if you remove the nozzle and see a plastic tube in your heat break, you DO NOT have an "all metal" head break.)

If your heat break is not "all metal" then heat to about 220C, remove the nozzle. Check the PTFE tubein the heat break. If it is not perfectly round and flush to the bottom of the heat break, then your filament is going to jam up there. Replace the heat break.

If that tube looks perfect, then you are getting "heat creep" up the heat break. Either you have poor spacing to the heat sink above or your temperature is too high for the fan that is cooling the heat sink. Mount a newer fan with the largest CFM value you can find. In one case where the stock fan was a 25mm one, I moved that fan over and put on a second 25mm fan. My jams stopped. In another case I yanked the 30mm fan off and put on a 40mm fan, there too the problem stopped. In a THIRD case I noticed that the air flow path was poor, I rotated my 30mm fan so that the air blew off to an open air part of the end effector - then this one stopped jamming.

If you have a true "all metal" heat break then you almost certainly have heat creep and need to increase your cooling and/or reduce your melt temperature.

Sometimes you just have a crappy nozzle. I have had crappy $25 E3D nozzles and brilliant $1.50 Chinese knock-offs. What you paid is NOT a guarantee of quality so try another nozzle and see if the problem improves. I buy nozzles by the handful for this reason.

Don't let your filament sit in the nozzle doing nothing while hot for a long period of time, it can get soft further up the tube and cause a blob inside the hot end, then when you shut down you'll end up with a blob above and below the heat break, guaranteed to clog.

Finally, if you have filament that you have left out and you have a humid print room, then your filament may have absorbed moisture and is behaving poorly. Dry the filament out and try again.

I have seen every one of the above solutions take care of persistently jamming systems. Go for it.

DLC

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Kits: Folgertech Kossel 2020 upgraded E3Dv6, Anet A8 upgraded E3Dv6, Tevo Tarantula enhanced parts and dual-head, TronXY X5SA Pro(E3DHemera).
Scratch: Large bed Cartesian, exchangeable heads, Linear slide Delta, Maker-Beam XL Micro Delta, 220x220CoreXY.

Chinese E3D clones have a narrow temp band between getting a good melt and then having bad heat creep.
This will show itself after 10-20-30minutes with increased stringing and blobbing.

The E3D clones that I have are also very particular with the retraction. the default of 4-6mm is far, far too much. I have mine dialed down to 1.5mm

Both of these will vary with your filament brand and type too.

Good Luck.