Filament flow Intermittent Inconsistency
 
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MKRMVZ
(@mkrmvz)
Active Member
Filament flow Intermittent Inconsistency

FIRST POST. Greetings.

Printing from an i3MK2s
Filament type PLA from the MK2s kit package.
temps are all by the book 215/55

Problem: Image link below
When printing the V2 calibration file the filament bead that is laid down on the bed is imperfect. It starts as a blob then for the first two centimeters is good then by the third centimeter the filament bead thins out and appears to have too little filament then suddenly the filament thickens again and then thins again eventually the filament loses adhesion to the bed.

Observation:
When I run the load filament function, the shifting in volume of filament extruded does not repeat. The filament comes out smoothly and does not indicate a clogged nozzle or clogged gear

Things I have already done.
Checked the gears for gunk.
Run the extruder Load filament
Checked the tension springs on the filament door and set them to 14mm
Increased flow through slicer settings ( this caused blobs )
Slowed down speed to 80% ( this changed nothing )

Some background.
I am a newbie in to 3D printing. I built my MK2s from a kit and have successfully printed the whistle, and the Rhino skull. The frog keeps failing cause of lifting of the PLA off the bed. Now I am printing my own designs and cannot even get through printing the raft layer because of this problem with filament flow. HELP!

thank you.
https://imgur.com/aYZMIyg

https://www.instagram.com/whatiswhatdotcom/
Posted : 11/03/2018 8:23 pm
Frans Krau
(@frans-krau)
Trusted Member
Re: Filament flow Intermittent Inconsistency

I think this is a typical Z adjust issue. See the forum about it (adjust Z my way). Use the Z adjust to lower your hotend so the filament is properly pushed to the heatbed.

Frans

Frans Krau
Europe, Holland, Apeldoorn

Posted : 11/03/2018 9:43 pm
MKRMVZ
(@mkrmvz)
Active Member
Topic starter answered:
Re: Filament flow Intermittent Inconsistency

Thank you .. I played with the Z axis a lot.. actually think i might have damaged the surface a little getting it too close. The filament practically embedded. If you look at the image from the original post you can make out scrape marks on the bed where i had to really dig with a rounded edge to break off the filament bead. I will try some more tinkering with the z. Most frustrating is that I had already successful prints and not going backwards.

https://www.instagram.com/whatiswhatdotcom/
Posted : 12/03/2018 12:23 am
MKRMVZ
(@mkrmvz)
Active Member
Topic starter answered:
Re: Filament flow Intermittent Inconsistency

Not the Z axis.. still trouble shoting

https://www.instagram.com/whatiswhatdotcom/
Posted : 12/03/2018 7:25 am
rob.l6
(@rob-l6)
Honorable Member
Re: Filament flow Intermittent Inconsistency

Still smells a lot like either bad z height or partial blockage, or perhaps a bit of both.

For z height, don't use that file, try the calibration squares, something like https://www.thingiverse.com/thing:1776031

For a partial blockage, turn up the hotend temp to about 280C and stick the needle in out a few times.

Posted : 12/03/2018 8:48 am
MKRMVZ
(@mkrmvz)
Active Member
Topic starter answered:
Re: Filament flow Intermittent Inconsistency

Ok. Thank you. I am convinced that it is a partial blockage that creates fluctuations in the flow volume. I loaded filament and it appeared to flow normal the first few times then all of a sudden it started looping up back to the nozzle. It formed a loop, knotted up then dropped with increased weight. Now.. The thing about this needle. I don't have one. Was it included in the kit and I missed it? Where does one acquire "acupuncture needles" . Thank you kindly for the generous advice.

https://www.instagram.com/whatiswhatdotcom/
Posted : 12/03/2018 10:49 pm
rob.l6
(@rob-l6)
Honorable Member
Re: Filament flow Intermittent Inconsistency

Yes, they were included in the kit. Very small so easy to miss and throw out with the packaging.

As to getting some, online, or perhaps try your local physiotherapy clinic? But don't tell them why you want one 😆

Posted : 13/03/2018 3:02 am
MKRMVZ
(@mkrmvz)
Active Member
Topic starter answered:
Re: Filament flow Intermittent Inconsistency

I cannot source an acupuncture needle. Stopped by an acupuncturist and started talking about needing to clear a nozzle and they literally said they could not give me a needle because...... Insurance. What other options do I have. Fully disassemble? I cannot wait any longer. 😥

https://www.instagram.com/whatiswhatdotcom/
Posted : 13/03/2018 8:07 pm
MKRMVZ
(@mkrmvz)
Active Member
Topic starter answered:
Re: Filament flow Intermittent Inconsistency

Ok. answered my own question. Treated my partial blockage like a full blockage. I went through the process of pushing a 1.5mm wire through the extruder. Pushed the filament out of the extruder chamber through the nozzle. Looked good coming out with each push. Once I wasn't getting any more filament release, I loaded new filament and the flow of the filament continued to curve back up to the nozzle, knot up, and then drop after accruing enough buildup to form what looked like a rope with a noose at the end of it ( is this printer possessed? )

https://www.instagram.com/whatiswhatdotcom/
Posted : 13/03/2018 9:33 pm
rob.l6
(@rob-l6)
Honorable Member
Re: Filament flow Intermittent Inconsistency

But have you actually tried to do a test print since then? And you are the using the PLA that came with the printer?

Posted : 14/03/2018 1:37 am
MKRMVZ
(@mkrmvz)
Active Member
Topic starter answered:
Re: Filament flow Intermittent Inconsistency

test print failed. I am going to step through the entire leveling process again and then let you know. I will use the same filament that was sent with the kit and also other pla filament that I know works form another printer ( makerbot ) a friend has. Will post up again. Thank you for your kindness in helping me through the pains of getting this new machine calibrated.

https://www.instagram.com/whatiswhatdotcom/
Posted : 14/03/2018 1:41 am
rob.l6
(@rob-l6)
Honorable Member
Re: Filament flow Intermittent Inconsistency


Thank you for your kindness in helping me through the pains of getting this new machine calibrated.

Life can be frustrating at times, goes double for 3d printers 😉

Posted : 14/03/2018 3:05 am
MKRMVZ
(@mkrmvz)
Active Member
Topic starter answered:
Re: Filament flow Intermittent Inconsistency

Disappointed to share that I am still not able to pull off clean prints. I suspect now that there is an issue with the extruder build. To get the filament to soften up and stick to the plate I have to crank up the heat on the PLA to 253. Once I do this the filament comes out buttery and lays down. There are still problems however with the flow of the filament. It is definitely not a partial nozzle blockage as I have thoroughly cleaned out the nozzle. What appeared to be a blockage might have actually been an issue with the filament not completely melting and thus extruding unevenly. With the extruder nozzle set to 253 the flow starts out fine but after just a minute there is a consistent ( over multiple prints ) loss of volume. The bead on the plate thins out and appears to ripple for a centimeter or two then it cleans up but when it continues it is at a slightly lower volume for the remainder of the print. The Z axis is in place. This is getting to be quite frustrating for me and the people I am working with waiting on me to print. IF I do not clear this up in the next 24hrs I will be forced to use a printing service. Tempted to completely disassemble the extruder and rebuild it.

https://www.instagram.com/whatiswhatdotcom/
Posted : 15/03/2018 5:07 pm
rob.l6
(@rob-l6)
Honorable Member
Re: Filament flow Intermittent Inconsistency

Perhaps before you start stripping stuff down, do a firmware reset (and redo the whole calibration process), make sure you are at the latest firmware, give the bed a good clean with IPA. And give it one last try.

Good luck.

Posted : 16/03/2018 11:55 am
MKRMVZ
(@mkrmvz)
Active Member
Topic starter answered:
Re: Filament flow Intermittent Inconsistency

Thank you again for your advice. I started to disassemble the extruder after updating the firmware. That is when I noticed the thermistor. The thermistor was not seated fully into the cavity of the block. I fixed this then ran into feed issues and realized the tension springs were too tight and then finally the temp for the PLA was about seven degrees under what it needed to be to run butter smooth prints. I am back in action now! Was quite frustrating though.

https://www.instagram.com/whatiswhatdotcom/
Posted : 22/03/2018 10:23 pm
rob.l6
(@rob-l6)
Honorable Member
Re: Filament flow Intermittent Inconsistency


I am back in action now! Was quite frustrating though.

Glad you found the problem.

Posted : 23/03/2018 2:41 am
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