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Filament constantly gets stuck in a nozzle

Posted by voxfuc 
Filament constantly gets stuck in a nozzle
June 13, 2019 11:16AM
Hello,
I created a 3d printer with Marlin software, after setting up Marlin i wanted to print my first object - calibration cube. From the nozzle spils out a little of filament whilst extruder is unable to push filament in correct way and the filament in the extruder comes back. I wasn't able to print even one print. After clearing up the nozzle and trying to push the filament by myself, i think, a right amount of filament spilled out, but i did it by pushing it, extruder couldn't.

I am using J-HEAD V6 Long 1,75mm/0.4mm.

I tried 190, 200, 220 degrees with PLA.


Marlin conf:
#define DEFAULT_AXIS_STEPS_PER_UNIT { 80, 80, 4000, 100 }
#define DEFAULT_MAX_FEEDRATE { 200, 200, 2, 20 }

Thanks in advance,
voxfuc

Edited 2 time(s). Last edit at 06/13/2019 11:36AM by voxfuc.
Re: Filament constantly gets stuck in a nozzle
June 13, 2019 12:29PM
Does the extruder motor skip steps or does the filament squeeze out of the top of the heater block? Try increasing motor current, or tighten the heater block or replace it, ie with an e3d v6.
It could also be that the heat break needs cooling. I never needed it with the j head though.


--
Kind regards
Imqqmi

NFAN CoreXY printer:
[reprap.org]
VDX
Re: Filament constantly gets stuck in a nozzle
June 13, 2019 01:00PM
... not enough heat ... or motor not strong enough ...

Try with higher temperatures ...


Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org]
Call for the project "garbage-free seas" - [reprap.org]
Re: Filament constantly gets stuck in a nozzle
June 13, 2019 02:06PM
Thanks for replys. The stepper does not skip steps it rotate all the time but the filament is not be able to flow out and new one is being pushed so the extruder damages filament.
Re: Filament constantly gets stuck in a nozzle
June 13, 2019 02:06PM
I will try to increase the temperature but 220 isnt enough for PLA?
btw I use bowden tube

Edited 1 time(s). Last edit at 06/13/2019 02:06PM by voxfuc.
Re: Filament constantly gets stuck in a nozzle
June 13, 2019 02:52PM
So i have already increased hot end temp to 230 degrees and the results:

Movie [click]
Re: Filament constantly gets stuck in a nozzle
June 13, 2019 03:09PM
I leveled table again and started printing. So far it looks pretty good... I will write after print will end
VDX
Re: Filament constantly gets stuck in a nozzle
June 13, 2019 04:35PM
... you'll need some "adhesive" coating on the plate - you can try with a glue/water solution or hairspray ...


Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org]
Call for the project "garbage-free seas" - [reprap.org]
Re: Filament constantly gets stuck in a nozzle
June 13, 2019 05:22PM
Okay, so the object has peeled off at the end of the printing process so i decided to connect heatbed. But after a while the mosfet started smoking... I think i should have used a radiator for it or fan right?
Re: Filament constantly gets stuck in a nozzle
June 13, 2019 05:23PM
@VDX Would a paper tape be good? I saw on yt this solution

Edited 1 time(s). Last edit at 06/13/2019 05:23PM by voxfuc.
VDX
Re: Filament constantly gets stuck in a nozzle
June 13, 2019 06:52PM
... this depends -- some of the common used "blue masking tapes" are pretty sticky for PLA, others not ...


Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org]
Call for the project "garbage-free seas" - [reprap.org]
Re: Filament constantly gets stuck in a nozzle
June 14, 2019 03:17AM
A smoking mosfet is deginitely not good, no it shouldn't need a heatsink unless a non logic level mosfet is used. The heat disdipation is a lot higher. If you've dome (de)soldering skills you could try to replace it. Please pay close attentiin to the pinout!

If the filament gets grinded up by the hobbed bolt, try loosen the tension. Toothmarks are ok but the fikament shouldn't be deformed otherwise.

As for sticking, pva glue (standard 'school' glue) works well, at 80 degrees bed temperature it sticks really well for me. It's a bit high for pla, and a bit low for abs though. To remove it, use hot water and some dishwashing soap. Use a plastic sheet to spread evenly. Adding water makes it bubbly for me. Ymmv.

Sticky paper tape can be used but may not stick well when the bed is heated. So leave the heater off, it's not stricly necessary for pka anyway. Some print surfaces need it for better sticking and release properties, ie sticks at higher temperatures and releases at lower temperatures.


--
Kind regards
Imqqmi

NFAN CoreXY printer:
[reprap.org]
Re: Filament constantly gets stuck in a nozzle
June 14, 2019 04:05AM
Thanks for replys. The mosfet is P55nf06l model. It smoked but there is a possibility it wasn't mosfet but the plastic connector (shown in the photo). I measured my heatbed resistance and it has below 1 ohm. I found that heatbed resistance should be abut 1.4 - 1.6. What should i do to make heatbeed running? If i won't use heatbed can i turn on ramps without replacing the mosfet?
Attachments:
open | download - 64435785_1608182945980512_7107862302954618880_n.jpg (468.6 KB)
Re: Filament constantly gets stuck in a nozzle
June 14, 2019 07:49AM
Looks like your glass plate is resting on the bolt heads for the bed. This is causing an air gap to the hot bed so it wont do much when turned on.
I suggest you get a smaller glass plate that fits between the fixings and rests on the bed. Then glue or clip them together. Others here can probably provide other solutions.
You may also find it usefull to set the "lift on move" settings in the slicer to avoid draging the print.

How did you measure the bed resistance? Disconnect from the control board and measure at the leads.
Check the electrical connector - not sure how. But the part thats melted is on bothe a + voltage and - voltage so there may be a short circuit underneath.
Re: Filament constantly gets stuck in a nozzle
June 14, 2019 08:01AM
I tried a radiator on that mosfet but unfortunatly (i think) i burned it. I am unable to turn off the red light near D8/D9 outputs. So would it be enough to replace the burned mosfet with a new one and use Heatbed Power Module as in the movie [click] ?

I measured resistance with Universal meter ( Firstly i measured inner resistance of meter then measured the heatbed resistance and at the end substracted from the second value the first one) ~= 0.8 ohm
Re: Filament constantly gets stuck in a nozzle
June 14, 2019 08:02AM
Maybe should i open a new topic in a section related to hardware?

Edited 1 time(s). Last edit at 06/14/2019 08:03AM by voxfuc.
Re: Filament constantly gets stuck in a nozzle
June 14, 2019 08:08AM
What hotend design do you have? Original J-head or a Chinesium one? If it's a knockoff, can it be that it's an all-metal hotend? They seem to have issues with PLA. There are Chinese copies that use a small PTFE tube inside the throat to guide the PLA to the meltchamber. These are the best I've found.


http://www.marinusdebeer.nl/
Re: Filament constantly gets stuck in a nozzle
June 14, 2019 08:08AM
IRFZ 44N would be good replacement?
Re: Filament constantly gets stuck in a nozzle
June 14, 2019 08:57AM
@Ohmarinus i think it isn't orginal hotend, but i printed nearly whole calibration cube but at the end it peeled off
Re: Filament constantly gets stuck in a nozzle
June 14, 2019 02:45PM
Irfz44 should work, the irlb8743 would be even better. Mosfets often fail open. I would also replace the burnt screw terminal. Any resistance in such terminals can cause a buildup of heat. Especially if its charred. Yep that should do the trick, unless the mcu is damaged. Check if the gate is shorted to drain or source.


--
Kind regards
Imqqmi

NFAN CoreXY printer:
[reprap.org]
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